Status: Last call for comments
This specification refers to both HTML and XML attributes and IDL attributes, often in the same context. When it is not clear which is being referred to, they are referred to as content attributes for HTML and XML attributes, and IDL attributes for those defined on IDL interfaces. Similarly, the term "properties" is used for both JavaScript object properties and CSS properties. When these are ambiguous they are qualified as object properties and CSS properties respectively.
Generally, when the specification states that a feature applies to the HTML syntax or the XHTML syntax, it also includes the other. When a feature specifically only applies to one of the two languages, it is called out by explicitly stating that it does not apply to the other format, as in "for HTML, ... (this does not apply to XHTML)".
This specification uses the term document to refer to any use of HTML, ranging from short static documents to long essays or reports with rich multimedia, as well as to fully-fledged interactive applications.
For simplicity, terms such as shown, displayed, and visible might sometimes be used when referring to the way a document is rendered to the user. These terms are not meant to imply a visual medium; they must be considered to apply to other media in equivalent ways.
When an algorithm B says to return to another algorithm A, it implies that A called B. Upon returning to A, the implementation must continue from where it left off in calling B.
Status: Last call for comments
The specification uses the term supported when referring to whether a user agent has an implementation capable of decoding the semantics of an external resource. A format or type is said to be supported if the implementation can process an external resource of that format or type without critical aspects of the resource being ignored. Whether a specific resource is supported can depend on what features of the resource's format are in use.
For example, a PNG image would be considered to be in a supported format if its pixel data could be decoded and rendered, even if, unbeknownst to the implementation, the image also contained animation data.
A MPEG4 video file would not be considered to be in a supported format if the compression format used was not supported, even if the implementation could determine the dimensions of the movie from the file's metadata.
The term MIME type is used to refer to what is sometimes called an Internet media type in protocol literature. The term media type in this specification is used to refer to the type of media intended for presentation, as used by the CSS specifications. [RFC2046] [MQ]
A string is a valid MIME type if it matches the media-type
rule defined in section 3.7 "Media Types"
of RFC 2616. In particular, a valid MIME type may
include MIME type parameters. [HTTP]
A string is a valid MIME type with no parameters if it
matches the media-type
rule defined in section
3.7 "Media Types" of RFC 2616, but does not contain any U+003B
SEMICOLON characters (;). In other words, if it consists only of a
type and subtype, with no MIME Type parameters. [HTTP]
The term HTML MIME type is used to refer to the MIME types text/html
and
text/html-sandboxed
.
Status: Last call for comments
To ease migration from HTML to XHTML, UAs
conforming to this specification will place elements in HTML in the
http://www.w3.org/1999/xhtml
namespace, at least for
the purposes of the DOM and CSS. The term "HTML
elements", when used in this specification, refers to any
element in that namespace, and thus refers to both HTML and XHTML
elements.
Except where otherwise stated, all elements defined or mentioned
in this specification are in the
http://www.w3.org/1999/xhtml
namespace, and all
attributes defined or mentioned in this specification have no
namespace.
Attribute names are said to be XML-compatible if they
match the Name
production defined in XML, they contain no
U+003A COLON characters (:), and their first three characters are
not an ASCII case-insensitive match for the string
"xml
". [XML]
The term XML MIME type is used to refer to the MIME types text/xml
,
application/xml
, and any MIME
type whose subtype ends with the four characters "+xml
". [RFC3023]
Status: Last call for comments
The term root element, when not explicitly qualified as referring to the document's root element, means the furthest ancestor element node of whatever node is being discussed, or the node itself if it has no ancestors. When the node is a part of the document, then the node's root element is indeed the document's root element; however, if the node is not currently part of the document tree, the root element will be an orphaned node.
When an element's root element is the root element
of a Document
, it is said to be in a
Document
. An element is said to have been inserted into a
document when its root element changes and is now
the document's root element. Analogously, an element is
said to have been removed from a document when its root
element changes from being the document's root
element to being another element.
A node's home subtree is the subtree rooted at that
node's root element. When a node is in a
Document
, its home subtree is that
Document
's tree.
The Document
of a Node
(such as an
element) is the Document
that the Node
's
ownerDocument
IDL attribute returns. When a
Node
is in a Document
then
that Document
is always the Node
's
Document
, and the Node
's ownerDocument
IDL attribute thus always returns that
Document
.
The term tree order means a pre-order, depth-first
traversal of DOM nodes involved (through the parentNode
/childNodes
relationship).
When it is stated that some element or attribute is ignored, or treated as some other value, or handled as if it was something else, this refers only to the processing of the node after it is in the DOM. A user agent must not mutate the DOM in such situations.
The term text node refers to any Text
node, including CDATASection
nodes; specifically, any
Node
with node type TEXT_NODE
(3)
or CDATA_SECTION_NODE
(4). [DOMCORE]
A content attribute is said to change value only if its new value is different than its previous value; setting an attribute to a value it already has does not change it.
Status: Last call for comments
The construction "a Foo
object", where
Foo
is actually an interface, is sometimes used instead
of the more accurate "an object implementing the interface
Foo
".
An IDL attribute is said to be getting when its value is being retrieved (e.g. by author script), and is said to be setting when a new value is assigned to it.
If a DOM object is said to be live, then that means that any attributes returning that object must always return the same object (not a new object each time), and the attributes and methods on that object must operate on the actual underlying data, not a snapshot of the data.
The terms fire and dispatch are used interchangeably in the context of events, as in the DOM Events specifications. The term trusted event is used as defined by the DOM Events specification. [DOMEVENTS]
Status: Last call for comments
The term plugin is used to mean any content handler
that supports displaying content as part of the user agent's
rendering of a Document
object, but that neither acts
as a child browsing context of the
Document
nor introduces any Node
objects
to the Document
's DOM.
Typically such content handlers are provided by third parties, though a user agent can designate content handlers to be plugins.
One example of a plugin would be a PDF viewer that is instantiated in a browsing context when the user navigates to a PDF file. This would count as a plugin regardless of whether the party that implemented the PDF viewer component was the same as that which implemented the user agent itself. However, a PDF viewer application that launches separate from the user agent (as opposed to using the same interface) is not a plugin by this definition.
This specification does not define a mechanism for interacting with plugins, as it is expected to be user-agent- and platform-specific. Some UAs might opt to support a plugin mechanism such as the Netscape Plugin API; others might use remote content converters or have built-in support for certain types. [NPAPI]
Browsers should take extreme care when interacting with external content intended for plugins. When third-party software is run with the same privileges as the user agent itself, vulnerabilities in the third-party software become as dangerous as those in the user agent.
Status: Last call for comments. ISSUE-101 (us-ascii-ref) blocks progress to Last Call
The preferred MIME name of a character encoding is the name or alias labeled as "preferred MIME name" in the IANA Character Sets registry, if there is one, or the encoding's name, if none of the aliases are so labeled. [IANACHARSET]
An ASCII-compatible character encoding is a single-byte or variable-length encoding in which the bytes 0x09, 0x0A, 0x0C, 0x0D, 0x20 - 0x22, 0x26, 0x27, 0x2C - 0x3F, 0x41 - 0x5A, and 0x61 - 0x7A, ignoring bytes that are the second and later bytes of multibyte sequences, all correspond to single-byte sequences that map to the same Unicode characters as those bytes in ANSI_X3.4-1968 (US-ASCII). [RFC1345]
This includes such encodings as Shift_JIS, HZ-GB-2312, and variants of ISO-2022, even though it is possible in these encodings for bytes like 0x70 to be part of longer sequences that are unrelated to their interpretation as ASCII. It excludes such encodings as UTF-7, UTF-16, GSM03.38, and EBCDIC variants.
The term Unicode character is used to mean a Unicode scalar value (i.e. any Unicode code point that is not a surrogate code point). [UNICODE]
Status: Last call for comments
All diagrams, examples, and notes in this specification are non-normative, as are all sections explicitly marked non-normative. Everything else in this specification is normative.
The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in the normative parts of this document are to be interpreted as described in RFC2119. For readability, these words do not appear in all uppercase letters in this specification. [RFC2119]
Requirements phrased in the imperative as part of algorithms (such as "strip any leading space characters" or "return false and abort these steps") are to be interpreted with the meaning of the key word ("must", "should", "may", etc) used in introducing the algorithm.
This specification describes the conformance criteria for user agents (relevant to implementors) and documents (relevant to authors and authoring tool implementors).
There is no implied relationship between document conformance requirements and implementation conformance requirements. User agents are not free to handle non-conformant documents as they please; the processing model described in this specification applies to implementations regardless of the conformity of the input documents.
User agents fall into several (overlapping) categories with different conformance requirements.
Web browsers that support the XHTML syntax must process elements and attributes from the HTML namespace found in XML documents as described in this specification, so that users can interact with them, unless the semantics of those elements have been overridden by other specifications.
A conforming XHTML processor would, upon
finding an XHTML script
element in an XML document,
execute the script contained in that element. However, if the
element is found within a transformation expressed in XSLT
(assuming the user agent also supports XSLT), then the processor
would instead treat the script
element as an opaque
element that forms part of the transform.
Web browsers that support the HTML syntax must process documents labeled with an HTML MIME type as described in this specification, so that users can interact with them.
User agents that support scripting must also be conforming implementations of the IDL fragments in this specification, as described in the Web IDL specification. [WEBIDL]
Unless explicitly stated, specifications that
override the semantics of HTML elements do not override the
requirements on DOM objects representing those elements. For
example, the script
element in the example above
would still implement the HTMLScriptElement
interface.
User agents that process HTML and XHTML documents purely to render non-interactive versions of them must comply to the same conformance criteria as Web browsers, except that they are exempt from requirements regarding user interaction.
Typical examples of non-interactive presentation user agents are printers (static UAs) and overhead displays (dynamic UAs). It is expected that most static non-interactive presentation user agents will also opt to lack scripting support.
A non-interactive but dynamic presentation UA would still execute scripts, allowing forms to be dynamically submitted, and so forth. However, since the concept of "focus" is irrelevant when the user cannot interact with the document, the UA would not need to support any of the focus-related DOM APIs.
Implementations that do not support scripting (or which have their scripting features disabled entirely) are exempt from supporting the events and DOM interfaces mentioned in this specification. For the parts of this specification that are defined in terms of an events model or in terms of the DOM, such user agents must still act as if events and the DOM were supported.
Scripting can form an integral part of an application. Web browsers that do not support scripting, or that have scripting disabled, might be unable to fully convey the author's intent.
Conformance checkers must verify that a document conforms to
the applicable conformance criteria described in this
specification. Automated conformance checkers are exempt from
detecting errors that require interpretation of the author's
intent (for example, while a document is non-conforming if the
content of a blockquote
element is not a quote,
conformance checkers running without the input of human judgement
do not have to check that blockquote
elements only
contain quoted material).
Conformance checkers must check that the input document conforms when parsed without a browsing context (meaning that no scripts are run, and that the parser's scripting flag is disabled), and should also check that the input document conforms when parsed with a browsing context in which scripts execute, and that the scripts never cause non-conforming states to occur other than transiently during script execution itself. (This is only a "SHOULD" and not a "MUST" requirement because it has been proven to be impossible. [COMPUTABLE])
The term "HTML5 validator" can be used to refer to a conformance checker that itself conforms to the applicable requirements of this specification.
XML DTDs cannot express all the conformance requirements of this specification. Therefore, a validating XML processor and a DTD cannot constitute a conformance checker. Also, since neither of the two authoring formats defined in this specification are applications of SGML, a validating SGML system cannot constitute a conformance checker either.
To put it another way, there are three types of conformance criteria:
A conformance checker must check for the first two. A simple DTD-based validator only checks for the first class of errors and is therefore not a conforming conformance checker according to this specification.
Applications and tools that process HTML and XHTML documents for reasons other than to either render the documents or check them for conformance should act in accordance with the semantics of the documents that they process.
A tool that generates document outlines but increases the nesting level for each paragraph and does not increase the nesting level for each section would not be conforming.
Authoring tools and markup generators must generate conforming documents. Conformance criteria that apply to authors also apply to authoring tools, where appropriate.
Authoring tools are exempt from the strict requirements of using elements only for their specified purpose, but only to the extent that authoring tools are not yet able to determine author intent. However, authoring tools must not automatically misuse elements or encourage their users to do so.
For example, it is not conforming to use an
address
element for arbitrary contact information;
that element can only be used for marking up contact information
for the author of the document or section. However, since an
authoring tool is likely unable to determine the difference, an
authoring tool is exempt from that requirement. This does not
mean, though, that authoring tools can use address
elements for any block of italics text (for instance); it just
means that the authoring tool doesn't have to verify that when the
user uses a tool for inserting contact information for a section,
that the user really is doing that and not inserting something
else instead.
In terms of conformance checking, an editor has to output documents that conform to the same extent that a conformance checker will verify.
When an authoring tool is used to edit a non-conforming document, it may preserve the conformance errors in sections of the document that were not edited during the editing session (i.e. an editing tool is allowed to round-trip erroneous content). However, an authoring tool must not claim that the output is conformant if errors have been so preserved.
Authoring tools are expected to come in two broad varieties: tools that work from structure or semantic data, and tools that work on a What-You-See-Is-What-You-Get media-specific editing basis (WYSIWYG).
The former is the preferred mechanism for tools that author HTML, since the structure in the source information can be used to make informed choices regarding which HTML elements and attributes are most appropriate.
However, WYSIWYG tools are legitimate. WYSIWYG tools should use
elements they know are appropriate, and should not use elements
that they do not know to be appropriate. This might in certain
extreme cases mean limiting the use of flow elements to just a few
elements, like div
, b
, i
,
and span
and making liberal use of the style
attribute.
All authoring tools, whether WYSIWYG or not, should make a best effort attempt at enabling users to create well-structured, semantically rich, media-independent content.
Some conformance requirements are phrased as requirements on elements, attributes, methods or objects. Such requirements fall into two categories: those describing content model restrictions, and those describing implementation behavior. Those in the former category are requirements on documents and authoring tools. Those in the second category are requirements on user agents. Similarly, some conformance requirements are phrased as requirements on authors; such requirements are to be interpreted as conformance requirements on the documents that authors produce. (In other words, this specification does not distinguish between conformance criteria on authors and conformance criteria on documents.)
Conformance requirements phrased as algorithms or specific steps may be implemented in any manner, so long as the end result is equivalent. (In particular, the algorithms defined in this specification are intended to be easy to follow, and not intended to be performant.)
User agents may impose implementation-specific limits on otherwise unconstrained inputs, e.g. to prevent denial of service attacks, to guard against running out of memory, or to work around platform-specific limitations.
For compatibility with existing content and prior specifications, this specification describes two authoring formats: one based on XML (referred to as the XHTML syntax), and one using a custom format inspired by SGML (referred to as the HTML syntax). Implementations may support only one of these two formats, although supporting both is encouraged.
The language in this specification assumes that the user agent expands all entity references, and therefore does not include entity reference nodes in the DOM. If user agents do include entity reference nodes in the DOM, then user agents must handle them as if they were fully expanded when implementing this specification. For example, if a requirement talks about an element's child text nodes, then any text nodes that are children of an entity reference that is a child of that element would be used as well. Entity references to unknown entities must be treated as if they contained just an empty text node for the purposes of the algorithms defined in this specification.
Status: Last call for comments
This specification relies on several other underlying specifications.
Implementations that support the XHTML syntax must support some version of XML, as well as its corresponding namespaces specification, because that syntax uses an XML serialization with namespaces. [XML] [XMLNS]
The Document Object Model (DOM) is a representation — a model — of a document and its content. The DOM is not just an API; the conformance criteria of HTML implementations are defined, in this specification, in terms of operations on the DOM. [DOMCORE]
Implementations must support some version of DOM Core and DOM Events, because this specification is defined in terms of the DOM, and some of the features are defined as extensions to the DOM Core interfaces. [DOMCORE] [DOMEVENTS]
In particular, the following features are defined in the DOM Core specification: [DOMCORE]
The following features are defined in the DOM Events specification: [DOMEVENTS]
The IDL fragments in this specification must be interpreted as required for conforming IDL fragments, as described in the Web IDL specification. [WEBIDL]
Except where otherwise specified, if an IDL
attribute that is a floating point number type (float
) is assigned an Infinity or Not-a-Number
(NaN) value, a NOT_SUPPORTED_ERR
exception must be
raised.
Except where otherwise specified, if a method with an argument
that is a floating point number type (float
)
is passed an Infinity or Not-a-Number (NaN) value, a
NOT_SUPPORTED_ERR
exception must be raised.
Some parts of the language described by this specification only support JavaScript as the underlying scripting language. [ECMA262]
The term "JavaScript" is used to refer to ECMA262,
rather than the official term ECMAScript, since the term
JavaScript is more widely known. Similarly, the MIME
type used to refer to JavaScript in this specification is
text/javascript
, since that is the most
commonly used type, despite it
being an officially obsoleted type according to RFC
4329. [RFC4329]
Implementations must support some version of the Media Queries language. [MQ]
Implementations must support the semantics of URLs defined in the URI and IRI specifications, as well as the semantics of IDNA domain names defined in the Internationalizing Domain Names in Applications (IDNA) specification. [RFC3986] [RFC3987] [RFC3490]
This specification does not require support of any particular network transport protocols, style sheet language, scripting language, or any of the DOM specifications beyond those described above. However, the language described by this specification is biased towards CSS as the styling language, JavaScript as the scripting language, and HTTP as the network protocol, and several features assume that those languages and protocols are in use.
This specification might have certain additional requirements on character encodings, image formats, audio formats, and video formats in the respective sections.
Status: Last call for comments. ISSUE-41 (Decentralized-extensibility) blocks progress to Last Call
Vendor-specific proprietary extensions to this specification are strongly discouraged. Documents must not use such extensions, as doing so reduces interoperability and fragments the user base, allowing only users of specific user agents to access the content in question.
If vendor-specific markup extensions are needed, they should be done using XML, with elements or attributes from custom namespaces. If such DOM extensions are needed, the members should be prefixed by vendor-specific strings to prevent clashes with future versions of this specification. Extensions must be defined so that the use of extensions neither contradicts nor causes the non-conformance of functionality defined in the specification.
For example, while strongly discouraged from doing so, an
implementation "Foo Browser" could add a new IDL attribute "fooTypeTime
" to a control's DOM interface that
returned the time it took the user to select the current value of a
control (say). On the other hand, defining a new control that
appears in a form's elements
array would be in violation of the above requirement, as it would
violate the definition of elements
given in this
specification.
When support for a feature is disabled (e.g. as an emergency measure to mitigate a security problem, or to aid in development, or for performance reasons), user agents must act as if they had no support for the feature whatsoever, and as if the feature was not mentioned in this specification. For example, if a particular feature is accessed via an attribute in a Web IDL interface, the attribute itself would be omitted from the objects that implement that interface — leaving the attribute on the object but making it return null or throw an exception is insufficient.
When vendor-neutral extensions to this specification are needed, either this specification can be updated accordingly, or an extension specification can be written that overrides the requirements in this specification. When someone applying this specification to their activities decides that they will recognise the requirements of such an extension specification, it becomes an applicable specification for the purposes of conformance requirements in this specification.
User agents must treat elements and attributes that they do not understand as semantically neutral; leaving them in the DOM (for DOM processors), and styling them according to CSS (for CSS processors), but not inferring any meaning from them.
Status: Last call for comments
Comparing two strings in a case-sensitive manner means comparing them exactly, code point for code point.
Comparing two strings in an ASCII case-insensitive manner means comparing them exactly, code point for code point, except that the characters in the range U+0041 to U+005A (i.e. LATIN CAPITAL LETTER A to LATIN CAPITAL LETTER Z) and the corresponding characters in the range U+0061 to U+007A (i.e. LATIN SMALL LETTER A to LATIN SMALL LETTER Z) are considered to also match.
Comparing two strings in a compatibility caseless manner means using the Unicode compatibility caseless match operation to compare the two strings. [UNICODE]
Converting a string to ASCII uppercase means replacing all characters in the range U+0061 to U+007A (i.e. LATIN SMALL LETTER A to LATIN SMALL LETTER Z) with the corresponding characters in the range U+0041 to U+005A (i.e. LATIN CAPITAL LETTER A to LATIN CAPITAL LETTER Z).
Converting a string to ASCII lowercase means replacing all characters in the range U+0041 to U+005A (i.e. LATIN CAPITAL LETTER A to LATIN CAPITAL LETTER Z) with the corresponding characters in the range U+0061 to U+007A (i.e. LATIN SMALL LETTER A to LATIN SMALL LETTER Z).
A string pattern is a prefix match for a string s when pattern is not longer than s and truncating s to pattern's length leaves the two strings as matches of each other.
Status: Last call for comments
There are various places in HTML that accept particular data types, such as dates or numbers. This section describes what the conformance criteria for content in those formats is, and how to parse them.
Implementors are strongly urged to carefully examine any third-party libraries they might consider using to implement the parsing of syntaxes described below. For example, date libraries are likely to implement error handling behavior that differs from what is required in this specification, since error-handling behavior is often not defined in specifications that describe date syntaxes similar to those used in this specification, and thus implementations tend to vary greatly in how they handle errors.
Status: Last call for comments
The space characters, for the purposes of this specification, are U+0020 SPACE, U+0009 CHARACTER TABULATION (tab), U+000A LINE FEED (LF), U+000C FORM FEED (FF), and U+000D CARRIAGE RETURN (CR).
The White_Space characters are those that have the Unicode property "White_Space". [UNICODE]
The alphanumeric ASCII characters are those in the ranges U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), U+0041 LATIN CAPITAL LETTER A to U+005A LATIN CAPITAL LETTER Z, U+0061 LATIN SMALL LETTER A to U+007A LATIN SMALL LETTER Z.
Some of the micro-parsers described below follow the pattern of having an input variable that holds the string being parsed, and having a position variable pointing at the next character to parse in input.
For parsers based on this pattern, a step that requires the user agent to collect a sequence of characters means that the following algorithm must be run, with characters being the set of characters that can be collected:
Let input and position be the same variables as those of the same name in the algorithm that invoked these steps.
Let result be the empty string.
While position doesn't point past the end of input and the character at position is one of the characters, append that character to the end of result and advance position to the next character in input.
Return result.
The step skip whitespace means that the user agent must collect a sequence of characters that are space characters. The step skip White_Space characters means that the user agent must collect a sequence of characters that are White_Space characters. In both cases, the collected characters are not used. [UNICODE]
When a user agent is to strip line breaks from a string, the user agent must remove any U+000A LINE FEED (LF) and U+000D CARRIAGE RETURN (CR) characters from that string.
The code-point length of a string is the number of Unicode code points in that string.
Status: Last call for comments
A number of attributes are boolean attributes. The presence of a boolean attribute on an element represents the true value, and the absence of the attribute represents the false value.
If the attribute is present, its value must either be the empty string or a value that is an ASCII case-insensitive match for the attribute's canonical name, with no leading or trailing whitespace.
The values "true" and "false" are not allowed on boolean attributes. To represent a false value, the attribute has to be omitted altogether.
Status: Last call for comments
Some attributes are defined as taking one of a finite set of keywords. Such attributes are called enumerated attributes. The keywords are each defined to map to a particular state (several keywords might map to the same state, in which case some of the keywords are synonyms of each other; additionally, some of the keywords can be said to be non-conforming, and are only in the specification for historical reasons). In addition, two default states can be given. The first is the invalid value default, the second is the missing value default.
If an enumerated attribute is specified, the attribute's value must be an ASCII case-insensitive match for one of the given keywords that are not said to be non-conforming, with no leading or trailing whitespace.
When the attribute is specified, if its value is an ASCII case-insensitive match for one of the given keywords then that keyword's state is the state that the attribute represents. If the attribute value matches none of the given keywords, but the attribute has an invalid value default, then the attribute represents that state. Otherwise, if the attribute value matches none of the keywords but there is a missing value default state defined, then that is the state represented by the attribute. Otherwise, there is no default, and invalid values must be ignored.
When the attribute is not specified, if there is a missing value default state defined, then that is the state represented by the (missing) attribute. Otherwise, the absence of the attribute means that there is no state represented.
The empty string can be a valid keyword.
Status: Last call for comments
Status: Last call for comments
A string is a valid non-negative integer if it consists of one or more characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9).
A valid non-negative integer represents the number that is represented in base ten by that string of digits.
The rules for parsing non-negative integers are as given in the following algorithm. When invoked, the steps must be followed in the order given, aborting at the first step that returns a value. This algorithm will return either zero, a positive integer, or an error. Leading spaces are ignored. Trailing spaces and any trailing garbage characters are ignored.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
If position is past the end of input, return an error.
If the character indicated by position
is a U+002B PLUS SIGN character (+), advance position to the next character. (The "+
" is ignored, but it is not conforming.)
If position is past the end of input, return an error.
If the character indicated by position is not one of U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then return an error.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), and interpret the resulting sequence as a base-ten integer. Let value be that integer.
Return value.
Status: Last call for comments
A string is a valid integer if it consists of one or more characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), optionally prefixed with a U+002D HYPHEN-MINUS character (-).
A valid integer without a U+002D HYPHEN-MINUS (-) prefix represents the number that is represented in base ten by that string of digits. A valid integer with a U+002D HYPHEN-MINUS (-) prefix represents the number represented in base ten by the string of digits that follows the U+002D HYPHEN-MINUS, subtracted from zero.
The rules for parsing integers are similar to the rules for non-negative integers, and are as given in the following algorithm. When invoked, the steps must be followed in the order given, aborting at the first step that returns a value. This algorithm will return either an integer or an error. Leading spaces are ignored. Trailing spaces and trailing garbage characters are ignored.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Let sign have the value "positive".
If position is past the end of input, return an error.
If the character indicated by position (the first character) is a U+002D HYPHEN-MINUS character (-):
Otherwise, if the character indicated by position (the first character) is a U+002B PLUS SIGN character (+):
+
" is ignored, but it is
not conforming.)If the character indicated by position is not one of U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then return an error.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), and interpret the resulting sequence as a base-ten integer. Let value be that integer.
If sign is "positive", return value, otherwise return the result of subtracting value from zero.
Status: Last call for comments
A string is a valid floating point number if it consists of:
A valid floating point number represents the number obtained by multiplying the significand by ten raised to the power of the exponent, where the significand is the first number, interpreted as base ten (including the decimal point and the number after the decimal point, if any, and interpreting the significand as a negative number if the whole string starts with a U+002D HYPHEN-MINUS character (-) and the number is not zero), and where the exponent is the number after the E, if any (interpreted as a negative number if there is a U+002D HYPHEN-MINUS character (-) between the E and the number and the number is not zero, or else ignoring a U+002B PLUS SIGN character (+) between the E and the number if there is one). If there is no E, then the exponent is treated as zero.
The Infinity and Not-a-Number (NaN) values are not valid floating point numbers.
The best representation of the number n as a floating point number is the string obtained from applying the JavaScript operator ToString to n. The JavaScript operator ToString is not uniquely determined. When there are multiple possible strings that could be obtained from the JavaScript operator ToString for a particular value, the user agent must always return the same string for that value (though it may differ from the value used by other user agents).
The rules for parsing floating point number values are as given in the following algorithm. This algorithm must be aborted at the first step that returns something. This algorithm will return either a number or an error. Leading spaces are ignored. Trailing spaces and garbage characters are ignored.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Let value have the value 1.
Let divisor have the value 1.
Let exponent have the value 1.
If position is past the end of input, return an error.
If the character indicated by position is a U+002D HYPHEN-MINUS character (-):
If the character indicated by position is not one of U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then return an error.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), and interpret the resulting sequence as a base-ten integer. Multiply value by that integer.
If the character indicated by position is a U+002E FULL STOP (.), run these substeps:
Advance position to the next character.
If position is past the end of input, or if the character indicated by position is not one of U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then jump to the step labeled conversion.
Fraction loop: Multiply divisor by ten.
Advance position to the next character.
If position is past the end of input, then jump to the step labeled conversion.
If the character indicated by position is one of U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), jump back to the step labeled fraction loop in these substeps.
If the character indicated by position is a U+0065 LATIN SMALL LETTER E character (e) or a U+0045 LATIN CAPITAL LETTER E character (E), run these substeps:
Advance position to the next character.
If position is past the end of input, then jump to the step labeled conversion.
If the character indicated by position is a U+002D HYPHEN-MINUS character (-):
If position is past the end of input, then jump to the step labeled conversion.
Otherwise, if the character indicated by position is a U+002B PLUS SIGN character (+):
If position is past the end of input, then jump to the step labeled conversion.
If the character indicated by position is not one of U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then jump to the step labeled conversion.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), and interpret the resulting sequence as a base-ten integer. Multiply exponent by that integer.
Multiply value by ten raised to the exponentth power.
Conversion: Let S be the set of finite IEEE 754 single-precision floating point values except −0, but with two special values added: 2128 and −2128.
Let rounded-value be the number in S that is closest to value, selecting the number with an even significand if there are two equally close values. (The two special values 2128 and −2128 are considered to have even significands for this purpose.)
If rounded-value is 2128 or −2128, return an error.
Return rounded-value.
Status: Last call for comments
The rules for parsing dimension values are as given in the following algorithm. When invoked, the steps must be followed in the order given, aborting at the first step that returns a value. This algorithm will return either a number greater than or equal to 1.0, or an error; if a number is returned, then it is further categorized as either a percentage or a length.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
If position is past the end of input, return an error.
If the character indicated by position is a U+002B PLUS SIGN character (+), advance position to the next character.
Collect a sequence of characters that are U+0030 DIGIT ZERO (0) characters, and discard them.
If position is past the end of input, return an error.
If the character indicated by position is not one of U+0031 DIGIT ONE (1) to U+0039 DIGIT NINE (9), then return an error.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), and interpret the resulting sequence as a base-ten integer. Let value be that number.
If position is past the end of input, return value as a length.
If the character indicated by position is a U+002E FULL STOP character (.):
Advance position to the next character.
If position is past the end of input, or if the character indicated by position is not one of U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then return value as a length.
Let divisor have the value 1.
Fraction loop: Multiply divisor by ten.
Advance position to the next character.
If position is past the end of input, then return value as a length.
If the character indicated by position is one of U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), return to the step labeled fraction loop in these substeps.
If position is past the end of input, return value as a length.
If the character indicated by position is a U+0025 PERCENT SIGN character (%), return value as a percentage.
Return value as a length.
Status: Last call for comments
A valid list of integers is a number of valid integers separated by U+002C COMMA characters, with no other characters (e.g. no space characters). In addition, there might be restrictions on the number of integers that can be given, or on the range of values allowed.
The rules for parsing a list of integers are as follows:
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Let numbers be an initially empty list of integers. This list will be the result of this algorithm.
If there is a character in the string input at position position, and it is either a U+0020 SPACE, U+002C COMMA, or U+003B SEMICOLON character, then advance position to the next character in input, or to beyond the end of the string if there are no more characters.
If position points to beyond the end of input, return numbers and abort.
If the character in the string input at position position is a U+0020 SPACE, U+002C COMMA, or U+003B SEMICOLON character, then return to step 4.
Let negated be false.
Let value be 0.
Let started be false. This variable is set to true when the parser sees a number or a U+002D HYPHEN-MINUS character (-).
Let got number be false. This variable is set to true when the parser sees a number.
Let finished be false. This variable is set to true to switch parser into a mode where it ignores characters until the next separator.
Let bogus be false.
Parser: If the character in the string input at position position is:
Follow these substeps:
Follow these substeps:
Follow these substeps:
1,2,x,4
".Follow these substeps:
Follow these substeps:
Advance position to the next character in input, or to beyond the end of the string if there are no more characters.
If position points to a character (and not to beyond the end of input), jump to the big Parser step above.
If negated is true, then negate value.
If got number is true, then append value to the numbers list.
Return the numbers list and abort.
Status: Last call for comments
The rules for parsing a list of dimensions are as follows. These rules return a list of zero or more pairs consisting of a number and a unit, the unit being one of percentage, relative, and absolute.
Let raw input be the string being parsed.
If the last character in raw input is a U+002C COMMA character (,), then remove that character from raw input.
Split the string raw input on commas. Let raw tokens be the resulting list of tokens.
Let result be an empty list of number/unit pairs.
For each token in raw tokens, run the following substeps:
Let input be the token.
Let position be a pointer into input, initially pointing at the start of the string.
Let value be the number 0.
Let unit be absolute.
If position is past the end of input, set unit to relative and jump to the last substep.
If the character at position is a character in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), interpret the resulting sequence as an integer in base ten, and increment value by that integer.
If the character at position is a U+002E FULL STOP character (.), run these substeps:
Collect a sequence of characters consisting of space characters and characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). Let s be the resulting sequence.
Remove all space characters in s.
If s is not the empty string, run these subsubsteps:
Let length be the number of characters in s (after the spaces were removed).
Let fraction be the result of interpreting s as a base-ten integer, and then dividing that number by 10length.
Increment value by fraction.
If the character at position is a U+0025 PERCENT SIGN character (%), then set unit to percentage.
Otherwise, if the character at position is a U+002A ASTERISK character (*), then set unit to relative.
Add an entry to result consisting of the number given by value and the unit given by unit.
Return the list result.
Status: Last call for comments
In the algorithms below, the number of days in month month of year year is: 31 if month is 1, 3, 5, 7, 8, 10, or 12; 30 if month is 4, 6, 9, or 11; 29 if month is 2 and year is a number divisible by 400, or if year is a number divisible by 4 but not by 100; and 28 otherwise. This takes into account leap years in the Gregorian calendar. [GREGORIAN]
The digits in the date and time syntaxes defined in this section must be characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), used to express numbers in base ten.
While the formats described here are intended to be subsets of the corresponding ISO8601 formats, this specification defines parsing rules in much more detail than ISO8601. Implementors are therefore encouraged to carefully examine any date parsing libraries before using them to implement the parsing rules described below; ISO8601 libraries might not parse dates and times in exactly the same manner. [ISO8601]
Status: Last call for comments
A month consists of a specific proleptic Gregorian date with no time-zone information and no date information beyond a year and a month. [GREGORIAN]
A string is a valid month string representing a year year and month month if it consists of the following components in the given order:
The rules to parse a month string are as follows. This will return either a year and month, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Parse a month component to obtain year and month. If this returns nothing, then fail.
If position is not beyond the end of input, then fail.
Return year and month.
The rules to parse a month component, given an input string and a position, are as follows. This will return either a year and a month, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). If the collected sequence is not at least four characters long, then fail. Otherwise, interpret the resulting sequence as a base-ten integer. Let that number be the year.
If year is not a number greater than zero, then fail.
If position is beyond the end of input or if the character at position is not a U+002D HYPHEN-MINUS character, then fail. Otherwise, move position forwards one character.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). If the collected sequence is not exactly two characters long, then fail. Otherwise, interpret the resulting sequence as a base-ten integer. Let that number be the month.
If month is not a number in the range 1 ≤ month ≤ 12, then fail.
Return year and month.
Status: Last call for comments
A date consists of a specific proleptic Gregorian date with no time-zone information, consisting of a year, a month, and a day. [GREGORIAN]
A string is a valid date string representing a year year, month month, and day day if it consists of the following components in the given order:
The rules to parse a date string are as follows. This will return either a date, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Parse a date component to obtain year, month, and day. If this returns nothing, then fail.
If position is not beyond the end of input, then fail.
Let date be the date with year year, month month, and day day.
Return date.
The rules to parse a date component, given an input string and a position, are as follows. This will return either a year, a month, and a day, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Parse a month component to obtain year and month. If this returns nothing, then fail.
Let maxday be the number of days in month month of year year.
If position is beyond the end of input or if the character at position is not a U+002D HYPHEN-MINUS character, then fail. Otherwise, move position forwards one character.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). If the collected sequence is not exactly two characters long, then fail. Otherwise, interpret the resulting sequence as a base-ten integer. Let that number be the day.
If day is not a number in the range 1 ≤ day ≤ maxday, then fail.
Return year, month, and day.
Status: Last call for comments
A time consists of a specific time with no time-zone information, consisting of an hour, a minute, a second, and a fraction of a second.
A string is a valid time string representing an hour hour, a minute minute, and a second second if it consists of the following components in the given order:
The second component cannot be 60 or 61; leap seconds cannot be represented.
The rules to parse a time string are as follows. This will return either a time, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Parse a time component to obtain hour, minute, and second. If this returns nothing, then fail.
If position is not beyond the end of input, then fail.
Let time be the time with hour hour, minute minute, and second second.
Return time.
The rules to parse a time component, given an input string and a position, are as follows. This will return either an hour, a minute, and a second, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). If the collected sequence is not exactly two characters long, then fail. Otherwise, interpret the resulting sequence as a base-ten integer. Let that number be the hour.
If position is beyond the end of input or if the character at position is not a U+003A COLON character, then fail. Otherwise, move position forwards one character.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). If the collected sequence is not exactly two characters long, then fail. Otherwise, interpret the resulting sequence as a base-ten integer. Let that number be the minute.
Let second be a string with the value "0".
If position is not beyond the end of input and the character at position is a U+003A COLON, then run these substeps:
Advance position to the next character in input.
If position is beyond the end of input, or at the last character in input, or if the next two characters in input starting at position are not two characters both in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then fail.
Collect a sequence of characters that are either characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9) or U+002E FULL STOP characters. If the collected sequence has more than one U+002E FULL STOP characters, or if the last character in the sequence is a U+002E FULL STOP character, then fail. Otherwise, let the collected string be second instead of its previous value.
Interpret second as a base-ten number (possibly with a fractional part). Let second be that number instead of the string version.
If second is not a number in the range 0 ≤ second < 60, then fail.
Return hour, minute, and second.
Status: Last call for comments
A local date and time consists of a specific proleptic Gregorian date, consisting of a year, a month, and a day, and a time, consisting of an hour, a minute, a second, and a fraction of a second, but expressed without a time zone. [GREGORIAN]
A string is a valid local date and time string representing a date and time if it consists of the following components in the given order:
The rules to parse a local date and time string are as follows. This will return either a date and time, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Parse a date component to obtain year, month, and day. If this returns nothing, then fail.
If position is beyond the end of input or if the character at position is not a U+0054 LATIN CAPITAL LETTER T character (T) then fail. Otherwise, move position forwards one character.
Parse a time component to obtain hour, minute, and second. If this returns nothing, then fail.
If position is not beyond the end of input, then fail.
Let date be the date with year year, month month, and day day.
Let time be the time with hour hour, minute minute, and second second.
Return date and time.
Status: Last call for comments
A global date and time consists of a specific proleptic Gregorian date, consisting of a year, a month, and a day, and a time, consisting of an hour, a minute, a second, and a fraction of a second, expressed with a time-zone offset, consisting of a signed number of hours and minutes. [GREGORIAN]
A string is a valid global date and time string representing a date, time, and a time-zone offset if it consists of the following components in the given order:
This format allows for time-zone offsets from -23:59 to +23:59. In practice, however, the range of offsets of actual time zones is -12:00 to +14:00, and the minutes component of offsets of actual time zones is always either 00, 30, or 45.
The following are some examples of dates written as valid global date and time strings.
0037-12-13T00:00Z
"1979-10-14T12:00:00.001-04:00
"8592-01-01T02:09+02:09
"Several things are notable about these dates:
The best representation of the global date and time string datetime is the valid global date and time string representing datetime with the last character of the string not being a U+005A LATIN CAPITAL LETTER Z character (Z), even if the time zone is UTC, and with a U+002D HYPHEN-MINUS character (-) representing the sign of the time-zone offset when the time zone is UTC.
The rules to parse a global date and time string are as follows. This will return either a time in UTC, with associated time-zone offset information for round tripping or display purposes, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Parse a date component to obtain year, month, and day. If this returns nothing, then fail.
If position is beyond the end of input or if the character at position is not a U+0054 LATIN CAPITAL LETTER T character (T) then fail. Otherwise, move position forwards one character.
Parse a time component to obtain hour, minute, and second. If this returns nothing, then fail.
If position is beyond the end of input, then fail.
Parse a time-zone offset component to obtain timezonehours and timezoneminutes. If this returns nothing, then fail.
If position is not beyond the end of input, then fail.
Let time be the moment in time at year year, month month, day day, hours hour, minute minute, second second, subtracting timezonehours hours and timezoneminutes minutes. That moment in time is a moment in the UTC time zone.
Let timezone be timezonehours hours and timezoneminutes minutes from UTC.
Return time and timezone.
The rules to parse a time-zone offset component, given an input string and a position, are as follows. This will return either time-zone hours and time-zone minutes, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
If the character at position is a U+005A LATIN CAPITAL LETTER Z character (Z), then:
Let timezonehours be 0.
Let timezoneminutes be 0.
Advance position to the next character in input.
Otherwise, if the character at position is either a U+002B PLUS SIGN (+) or a U+002D HYPHEN-MINUS (-), then:
If the character at position is a U+002B PLUS SIGN (+), let sign be "positive". Otherwise, it's a U+002D HYPHEN-MINUS (-); let sign be "negative".
Advance position to the next character in input.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). If the collected sequence is not exactly two characters long, then fail. Otherwise, interpret the resulting sequence as a base-ten integer. Let that number be the timezonehours.
If position is beyond the end of input or if the character at position is not a U+003A COLON character, then fail. Otherwise, move position forwards one character.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). If the collected sequence is not exactly two characters long, then fail. Otherwise, interpret the resulting sequence as a base-ten integer. Let that number be the timezoneminutes.
Otherwise, fail.
Return timezonehours and timezoneminutes.
Status: Last call for comments
A week consists of a week-year number and a week number representing a seven-day period starting on a Monday. Each week-year in this calendaring system has either 52 or 53 such seven-day periods, as defined below. The seven-day period starting on the Gregorian date Monday December 29th 1969 (1969-12-29) is defined as week number 1 in week-year 1970. Consecutive weeks are numbered sequentially. The week before the number 1 week in a week-year is the last week in the previous week-year, and vice versa. [GREGORIAN]
A week-year with a number year has 53 weeks if it corresponds to either a year year in the proleptic Gregorian calendar that has a Thursday as its first day (January 1st), or a year year in the proleptic Gregorian calendar that has a Wednesday as its first day (January 1st) and where year is a number divisible by 400, or a number divisible by 4 but not by 100. All other week-years have 52 weeks.
The week number of the last day of a week-year with 53 weeks is 53; the week number of the last day of a week-year with 52 weeks is 52.
The week-year number of a particular day can be different than the number of the year that contains that day in the proleptic Gregorian calendar. The first week in a week-year y is the week that contains the first Thursday of the Gregorian year y.
A string is a valid week string representing a week-year year and week week if it consists of the following components in the given order:
The rules to parse a week string are as follows. This will return either a week-year number and week number, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). If the collected sequence is not at least four characters long, then fail. Otherwise, interpret the resulting sequence as a base-ten integer. Let that number be the year.
If year is not a number greater than zero, then fail.
If position is beyond the end of input or if the character at position is not a U+002D HYPHEN-MINUS character, then fail. Otherwise, move position forwards one character.
If position is beyond the end of input or if the character at position is not a U+0057 LATIN CAPITAL LETTER W character (W), then fail. Otherwise, move position forwards one character.
Collect a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9). If the collected sequence is not exactly two characters long, then fail. Otherwise, interpret the resulting sequence as a base-ten integer. Let that number be the week.
Let maxweek be the week number of the last day of year year.
If week is not a number in the range 1 ≤ week ≤ maxweek, then fail.
If position is not beyond the end of input, then fail.
Return the week-year number year and the week number week.
Status: Last call for comments
A string is a valid date or time string if it is also one of the following:
A string is a valid date or time string in content if it consists of zero or more White_Space characters, followed by a valid date or time string, followed by zero or more further White_Space characters.
A string is a valid date string with optional time if it is also one of the following:
A string is a valid date string in content with optional time if it consists of zero or more White_Space characters, followed by a valid date string with optional time, followed by zero or more further White_Space characters.
The rules to parse a date or time string are as follows. The algorithm is invoked with a flag indicating if the in attribute variant or the in content variant is to be used. The algorithm will return either a date, a time, a global date and time, or nothing. If at any point the algorithm says that it "fails", this means that it is aborted at that point and returns nothing.
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
For the in content variant: skip White_Space characters.
Set start position to the same position as position.
Set the date present and time present flags to true.
Parse a date component to obtain year, month, and day. If this fails, then set the date present flag to false.
If date present is true, and position is not beyond the end of input, and the character at position is a U+0054 LATIN CAPITAL LETTER T character (T), then advance position to the next character in input.
Otherwise, if date present is true, and either position is beyond the end of input or the character at position is not a U+0054 LATIN CAPITAL LETTER T character (T), then set time present to false.
Otherwise, if date present is false, set position back to the same position as start position.
If the time present flag is true, then parse a time component to obtain hour, minute, and second. If this returns nothing, then set the time present flag to false.
If both the date present and time present flags are false, then fail.
If the date present and time present flags are both true, but position is beyond the end of input, then fail.
If the date present and time present flags are both true, parse a time-zone offset component to obtain timezonehours and timezoneminutes. If this returns nothing, then fail.
For the in content variant: skip White_Space characters.
If position is not beyond the end of input, then fail.
If the date present flag is true and the time present flag is false, then let date be the date with year year, month month, and day day, and return date.
Otherwise, if the time present flag is true and the date present flag is false, then let time be the time with hour hour, minute minute, and second second, and return time.
Otherwise, let time be the moment in time at year year, month month, day day, hours hour, minute minute, second second, subtracting timezonehours hours and timezoneminutes minutes, that moment in time being a moment in the UTC time zone; let timezone be timezonehours hours and timezoneminutes minutes from UTC; and return time and timezone.
Status: Last call for comments
A simple color consists of three 8-bit numbers in the range 0..255, representing the red, green, and blue components of the color respectively, in the sRGB color space. [SRGB]
A string is a valid simple color if it is exactly seven characters long, and the first character is a U+0023 NUMBER SIGN character (#), and the remaining six characters are all in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), U+0041 LATIN CAPITAL LETTER A to U+0046 LATIN CAPITAL LETTER F, U+0061 LATIN SMALL LETTER A to U+0066 LATIN SMALL LETTER F, with the first two digits representing the red component, the middle two digits representing the green component, and the last two digits representing the blue component, in hexadecimal.
A string is a valid lowercase simple color if it is a valid simple color and doesn't use any characters in the range U+0041 LATIN CAPITAL LETTER A to U+0046 LATIN CAPITAL LETTER F.
The rules for parsing simple color values are as given in the following algorithm. When invoked, the steps must be followed in the order given, aborting at the first step that returns a value. This algorithm will return either a simple color or an error.
Let input be the string being parsed.
If input is not exactly seven characters long, then return an error.
If the first character in input is not a U+0023 NUMBER SIGN character (#), then return an error.
If the last six characters of input are not all in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), U+0041 LATIN CAPITAL LETTER A to U+0046 LATIN CAPITAL LETTER F, U+0061 LATIN SMALL LETTER A to U+0066 LATIN SMALL LETTER F, then return an error.
Let result be a simple color.
Interpret the second and third characters as a hexadecimal number and let the result be the red component of result.
Interpret the fourth and fifth characters as a hexadecimal number and let the result be the green component of result.
Interpret the sixth and seventh characters as a hexadecimal number and let the result be the blue component of result.
Return result.
The rules for serializing simple color values given a simple color are as given in the following algorithm:
Let result be a string consisting of a single U+0023 NUMBER SIGN character (#).
Convert the red, green, and blue components in turn to two-digit hexadecimal numbers using the digits U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9) and U+0061 LATIN SMALL LETTER A to U+0066 LATIN SMALL LETTER F, zero-padding if necessary, and append these numbers to result, in the order red, green, blue.
Return result, which will be a valid lowercase simple color.
Some obsolete legacy attributes parse colors in a more complicated manner, using the rules for parsing a legacy color value, which are given in the following algorithm. When invoked, the steps must be followed in the order given, aborting at the first step that returns a value. This algorithm will return either a simple color or an error.
Let input be the string being parsed.
If input is the empty string, then return an error.
If input is an ASCII
case-insensitive match for the string "transparent
", then return an error.
If input is an ASCII case-insensitive match for one of the keywords listed in the SVG color keywords or CSS2 System Colors sections of the CSS3 Color specification, then return the simple color corresponding to that keyword. [CSSCOLOR]
If input is four characters long, and the first character in input is a U+0023 NUMBER SIGN character (#), and the last three characters of input are all in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), U+0041 LATIN CAPITAL LETTER A to U+0046 LATIN CAPITAL LETTER F, and U+0061 LATIN SMALL LETTER A to U+0066 LATIN SMALL LETTER F, then run these substeps:
Let result be a simple color.
Interpret the second character of input as a hexadecimal digit; let the red component of result be the resulting number multiplied by 17.
Interpret the third character of input as a hexadecimal digit; let the green component of result be the resulting number multiplied by 17.
Interpret the fourth character of input as a hexadecimal digit; let the blue component of result be the resulting number multiplied by 17.
Return result.
Replace any characters in input that
have a Unicode code point greater than U+FFFF (i.e. any characters
that are not in the basic multilingual plane) with the
two-character string "00
".
If input is longer than 128 characters, truncate input, leaving only the first 128 characters.
If the first character in input is a U+0023 NUMBER SIGN character (#), remove it.
Replace any character in input that is not in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), U+0041 LATIN CAPITAL LETTER A to U+0046 LATIN CAPITAL LETTER F, and U+0061 LATIN SMALL LETTER A to U+0066 LATIN SMALL LETTER F with the character U+0030 DIGIT ZERO (0).
While input's length is zero or not a multiple of three, append a U+0030 DIGIT ZERO (0) character to input.
Split input into three strings of equal length, to obtain three components. Let length be the length of those components (one third the length of input).
If length is greater than 8, then remove the leading length-8 characters in each component, and let length be 8.
While length is greater than two and the first character in each component is a U+0030 DIGIT ZERO (0) character, remove that character and reduce length by one.
If length is still greater than two, truncate each component, leaving only the first two characters in each.
Let result be a simple color.
Interpret the first component as a hexadecimal number; let the red component of result be the resulting number.
Interpret the second component as a hexadecimal number; let the green component of result be the resulting number.
Interpret the third component as a hexadecimal number; let the blue component of result be the resulting number.
Return result.
Status: Last call for comments
A set of space-separated tokens is a string containing zero or more words separated by one or more space characters, where words consist of any string of one or more characters, none of which are space characters.
A string containing a set of space-separated tokens may have leading or trailing space characters.
An unordered set of unique space-separated tokens is a set of space-separated tokens where none of the words are duplicated.
An ordered set of unique space-separated tokens is a set of space-separated tokens where none of the words are duplicated but where the order of the tokens is meaningful.
Sets of space-separated tokens sometimes have a defined set of allowed values. When a set of allowed values is defined, the tokens must all be from that list of allowed values; other values are non-conforming. If no such set of allowed values is provided, then all values are conforming.
When a user agent has to split a string on spaces, it must use the following algorithm:
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Let tokens be a list of tokens, initially empty.
While position is not past the end of input:
Collect a sequence of characters that are not space characters.
Add the string collected in the previous step to tokens.
Return tokens.
When a user agent has to remove a token from a string, it must use the following algorithm:
Let input be the string being modified.
Let token be the token being removed. It will not contain any space characters.
Let output be the output string, initially empty.
Let position be a pointer into input, initially pointing at the start of the string.
If position is beyond the end of input, abort these steps.
If the character at position is a space character:
Append the character at position to the end of output.
Advance position so it points at the next character in input.
Return to step 5 in the overall set of steps.
Otherwise, the character at position is the first character of a token. Collect a sequence of characters that are not space characters, and let that be s.
If s is exactly equal to token, then:
Skip whitespace (in input).
Remove any space characters currently at the end of output.
If position is not past the end of input, and output is not the empty string, append a single U+0020 SPACE character at the end of output.
Otherwise, append s to the end of output.
Return to step 6 in the overall set of steps.
This causes any occurrences of the token to be removed from the string, and any spaces that were surrounding the token to be collapsed to a single space, except at the start and end of the string, where such spaces are removed.
Status: Last call for comments
A set of comma-separated tokens is a string containing zero or more tokens each separated from the next by a single U+002C COMMA character (,), where tokens consist of any string of zero or more characters, neither beginning nor ending with space characters, nor containing any U+002C COMMA characters (,), and optionally surrounded by space characters.
For instance, the string " a ,b,,d d
" consists of four
tokens: "a", "b", the empty string, and "d d". Leading and
trailing whitespace around each token doesn't count as part of the
token, and the empty string can be a token.
Sets of comma-separated tokens sometimes have further restrictions on what consists a valid token. When such restrictions are defined, the tokens must all fit within those restrictions; other values are non-conforming. If no such restrictions are specified, then all values are conforming.
When a user agent has to split a string on commas, it must use the following algorithm:
Let input be the string being parsed.
Let position be a pointer into input, initially pointing at the start of the string.
Let tokens be a list of tokens, initially empty.
Token: If position is past the end of input, jump to the last step.
Collect a sequence of characters that are not U+002C COMMA characters (,). Let s be the resulting sequence (which might be the empty string).
Remove any leading or trailing sequence of space characters from s.
Add s to tokens.
If position is not past the end of input, then the character at position is a U+002C COMMA character (,); advance position past that character.
Jump back to the step labeled token.
Return tokens.
Status: Last call for comments
A valid hash-name reference to an element of type type is a string consisting of a U+0023 NUMBER SIGN
character (#) followed by a string which exactly matches the value
of the name
attribute of an element with type
type in the document.
The rules for parsing a hash-name reference to an element of type type are as follows:
If the string being parsed does not contain a U+0023 NUMBER SIGN character, or if the first such character in the string is the last character in the string, then return null and abort these steps.
Let s be the string from the character immediately after the first U+0023 NUMBER SIGN character in the string being parsed up to the end of that string.
Return the first element of type type
that has an id
attribute whose value
is a case-sensitive match for s or
a name
attribute whose value is a
compatibility caseless match for s.
Status: Last call for comments
A string is a valid media query if it matches the
media_query_list
production of the Media
Queries specification. [MQ]
A string matches the environment of a view if it is the empty string, a string consisting of only space characters, or is a media query that matches that view's environment according to the definitions given in the Media Queries specification. [MQ]
Status: Last call for comments. ISSUE-56 (urls-webarch) and ISSUE-78 (urls-terminology) block progress to Last Call
Status: Last call for comments
A URL is a string used to identify a resource.
A URL is a valid URL if it is a valid Web address as defined by the Web addresses specification. [WEBADDRESSES]
A URL is an absolute URL if it is an absolute Web address as defined by the Web addresses specification. [WEBADDRESSES]
To parse a URL url into its component parts, the user agent must use the parse a Web address algorithm defined by the Web addresses specification. [WEBADDRESSES]
Parsing a URL results in the following components, again as defined by the Web addresses specification:
To resolve a URL to an absolute URL relative to either another absolute URL or an element, the user agent must use the resolve a Web address algorithm defined by the Web addresses specification. [WEBADDRESSES]
The document base URL of a Document
object is the absolute URL obtained by running these
substeps:
Let fallback base url be the document's address.
If fallback base url is
about:blank
, and the Document
's
browsing context has a creator browsing
context, then let fallback base url
be the document base URL of the creator
Document
instead.
If there is no base
element that is both a
child of the head
element and has an
href
attribute, then the
document base URL is fallback base
url.
Otherwise, let url be the value of the
href
attribute of the first
such element.
Resolve url relative to fallback base
url (thus, the base
href
attribute isn't affected by
xml:base
attributes).
The document base URL is the result of the previous step if it was successful; otherwise it is fallback base url.
This specification defines the URL
about:legacy-compat
as a reserved, though
unresolvable, about:
URI, for use in DOCTYPEs in HTML
documents when needed for compatibility with XML tools. [ABOUT]
This specification defines the URL
about:srcdoc
as a reserved, though
unresolvable, about:
URI, that is used as
the document's address of iframe
srcdoc
documents. [ABOUT]
The term "URL" in this specification is used in a manner distinct from the precise technical meaning it is given in RFC 3986. Readers familiar with that RFC will find it easier to read this specification if they pretend the term "URL" as used herein is really called something else altogether. This is a willful violation of RFC 3986. [RFC3986]
Status: Last call for comments
When an xml:base
attribute
changes, the attribute's element, and all descendant elements, are
affected by a base URL change.
When a document's document base URL changes, all elements in that document are affected by a base URL change.
When an element is moved from one document to another, if the two documents have different base URLs, then that element and all its descendants are affected by a base URL change.
When an element is affected by a base URL change, it must act as described in the following list:
If the absolute URL identified by the hyperlink is
being shown to the user, or if any data derived from that URL is
affecting the display, then the href
attribute should be re-resolved relative to the element
and the UI updated appropriately.
For example, the CSS :link
/:visited
pseudo-classes might have
been affected.
If the hyperlink has a ping
attribute and its absolute URL(s) are being shown to the
user, then the ping
attribute's tokens should be re-resolved relative to the element and the UI updated
appropriately.
q
, blockquote
,
section
, article
, ins
, or
del
element with a cite
attributeIf the absolute URL identified by the cite
attribute is being shown to the user, or if
any data derived from that URL is affecting the display, then the
URL should be re-resolved relative to the element and the UI updated
appropriately.
The element is not directly affected.
Changing the base URL doesn't affect the image
displayed by img
elements, although subsequent
accesses of the src
IDL attribute
from script will return a new absolute URL that might
no longer correspond to the image being shown.
Status: Last call for comments
An interface that has a complement of URL decomposition IDL attributes will have seven attributes with the following definitions:
attribute DOMString protocol; attribute DOMString host; attribute DOMString hostname; attribute DOMString port; attribute DOMString pathname; attribute DOMString search; attribute DOMString hash;
protocol
[ = value ]Returns the current scheme of the underlying URL.
Can be set, to change the underlying URL's scheme.
host
[ = value ]Returns the current host and port (if it's not the default port) in the underlying URL.
Can be set, to change the underlying URL's host and port.
The host and the port are separated by a colon. The port part, if omitted, will be assumed to be the current scheme's default port.
hostname
[ = value ]Returns the current host in the underlying URL.
Can be set, to change the underlying URL's host.
port
[ = value ]Returns the current port in the underlying URL.
Can be set, to change the underlying URL's port.
pathname
[ = value ]Returns the current path in the underlying URL.
Can be set, to change the underlying URL's path.
search
[ = value ]Returns the current query component in the underlying URL.
Can be set, to change the underlying URL's query component.
hash
[ = value ]Returns the current fragment identifier in the underlying URL.
Can be set, to change the underlying URL's fragment identifier.
The attributes defined to be URL decomposition IDL attributes must act as described for the attributes with the same corresponding names in this section.
In addition, an interface with a complement of URL decomposition IDL attributes will define an input, which is a URL that the attributes act on, and a common setter action, which is a set of steps invoked when any of the attributes' setters are invoked.
The seven URL decomposition IDL attributes have similar requirements.
On getting, if the input is an absolute URL that fulfills the condition given in the "getter condition" column corresponding to the attribute in the table below, the user agent must return the part of the input URL given in the "component" column, with any prefixes specified in the "prefix" column appropriately added to the start of the string and any suffixes specified in the "suffix" column appropriately added to the end of the string. Otherwise, the attribute must return the empty string.
On setting, the new value must first be mutated as described by the "setter preprocessor" column, then mutated by %-escaping any characters in the new value that are not valid in the relevant component as given by the "component" column. Then, if the input is an absolute URL and the resulting new value fulfills the condition given in the "setter condition" column, the user agent must make a new string output by replacing the component of the URL given by the "component" column in the input URL with the new value; otherwise, the user agent must let output be equal to the input. Finally, the user agent must invoke the common setter action with the value of output.
When replacing a component in the URL, if the component is part of an optional group in the URL syntax consisting of a character followed by the component, the component (including its prefix character) must be included even if the new value is the empty string.
The previous paragraph applies in particular to the
":
" before a <port> component, the "?
" before a <query> component, and the "#
" before a <fragment> component.
For the purposes of the above definitions, URLs must be parsed using the URL parsing rules defined in this specification.
Attribute | Component | Getter Condition | Prefix | Suffix | Setter Preprocessor | Setter Condition |
---|---|---|---|---|---|---|
protocol
| <scheme> | — | — | U+003A COLON (:) | Remove all trailing U+003A COLON characters (:) | The new value is not the empty string |
host
| <hostport> | input is hierarchical and uses a server-based naming authority | — | — | — | The new value is not the empty string and input is hierarchical and uses a server-based naming authority |
hostname
| <host> | input is hierarchical and uses a server-based naming authority | — | — | Remove all leading U+002F SOLIDUS characters (/) | The new value is not the empty string and input is hierarchical and uses a server-based naming authority |
port
| <port> | input is hierarchical, uses a server-based naming authority, and contained a <port> component (possibly an empty one) | — | — | Remove all characters in the new value from the first that is not in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), if any. Remove any leading U+0030 DIGIT ZERO characters (0) in the new value. If the resulting string is empty, set it to a single U+0030 DIGIT ZERO character (0). | input is hierarchical and uses a server-based naming authority, and the new value, when interpretted as a base-ten integer, is less than or equal to 65535 |
pathname
| <path> | input is hierarchical | — | — | If it has no leading U+002F SOLIDUS character (/), prepend a U+002F SOLIDUS character (/) to the new value | input is hierarchical |
search
| <query> | input is hierarchical, and contained a <query> component (possibly an empty one) | U+003F QUESTION MARK (?) | — | Remove one leading U+003F QUESTION MARK character (?), if any | input is hierarchical |
hash
| <fragment> | input contained a non-empty <fragment> component | U+0023 NUMBER SIGN (#) | — | Remove one leading U+0023 NUMBER SIGN character (#), if any | — |
The table below demonstrates how the getter condition for search
results in different results
depending on the exact original syntax of the URL:
Input URL | search value
| Explanation |
---|---|---|
http://example.com/
| empty string | No <query> component in input URL. |
http://example.com/?
| ?
| There is a <query> component, but it is empty. The question mark in the resulting value is the prefix. |
http://example.com/?test
| ?test
| The <query> component has the value "test ".
|
http://example.com/?test#
| ?test
| The (empty) <fragment> component is not part of the <query> component. |
Status: Last call for comments
When a user agent is to fetch a resource or URL, optionally from an origin origin, and optionally with a synchronous flag, the following steps must be run. (When a URL is to be fetched, the URL identifies a resource to be obtained.)
Generate the address of the resource from which Request-URIs
are obtained as required by HTTP for the Referer
(sic) header from the
document's current address of the appropriate
Document
as given by the following list. [HTTP]
Document
.Remove any <fragment> component from the generated address of the resource from which Request-URIs are obtained.
If the origin of the appropriate
Document
is not a scheme/host/port tuple, then the
Referer
(sic) header must be
omitted, regardless of its value.
If the algorithm was not invoked with the synchronous flag, perform the remaining steps asynchronously.
If the resource is identified by an absolute URL,
and the resource is to be obtained using an idempotent action
(such as an HTTP GET or
equivalent), and it is already being downloaded for other
reasons (e.g. another invocation of this algorithm), and this
request would be identical to the previous one (e.g. same Accept
and Origin
headers), and the user agent is
configured such that it is to reuse the data from the existing
download instead of initiating a new one, then use the results of
the existing download instead of starting a new one.
Otherwise, at a time convenient to the user and the user agent,
download (or otherwise obtain) the resource, applying the
semantics of the relevant specifications (e.g. performing an HTTP
GET or POST operation, or reading the file from disk, following
redirects, dereferencing javascript:
URLs, etc).
The HTTP specification requires that 301, 302, and 307 redirects, when applied to methods other than the safe methods, not be followed without user confirmation. [HTTP]
For the purposes of the Referer
(sic) header, use the
address of the resource from which Request-URIs are
obtained generated in the earlier step.
For the purposes of the Origin
header, if the fetching algorithm was
explicitly initiated from an origin, then the origin that initiated the HTTP request is origin. Otherwise, this is a request from
a "privacy-sensitive" context. [ORIGIN]
If the resource is identified by the URL
about:blank
, then the resource is
immediately available and consists of the empty string, with no
metadata.
If there are cookies to be set, then the user agent must run the following substeps:
Wait until ownership of the storage mutex can be taken by this instance of the fetching algorithm.
Take ownership of the storage mutex.
Update the cookies. [COOKIES]
Release the storage mutex so that it is once again free.
If the algorithm was not invoked with the synchronous flag: When the resource is available, or if there is an error of some description, queue a task that uses the resource as appropriate. If the resource can be processed incrementally, as, for instance, with a progressively interlaced JPEG or an HTML file, additional tasks may be queued to process the data as it is downloaded. The task source for these tasks is the networking task source.
Otherwise, return the resource or error information to the calling algorithm.
If the user agent can determine the actual length of the resource
being fetched for an instance of this
algorithm, and if that length is finite, then that length is the
file's size. Otherwise, the
subject of the algorithm (that is, the resource being fetched) has
no known size. (For
example, the HTTP Content-Length
header might
provide this information.)
The user agent must also keep track of the number of bytes downloaded for each instance of this algorithm. This number must exclude any out-of-band metadata, such as HTTP headers.
The application cache processing model introduces some changes to the networking model to handle the returning of cached resources.
The navigation processing model handles redirects itself, overriding the redirection handling that would be done by the fetching algorithm.
Whether the type sniffing rules apply to the fetched resource depends on the algorithm that invokes the rules — they are not always applicable.
Status: Last call for comments
User agents can implement a variety of transfer protocols, but this specification mostly defines behavior in terms of HTTP. [HTTP]
The HTTP GET method is equivalent to the default retrieval action of the protocol. For example, RETR in FTP. Such actions are idempotent and safe, in HTTP terms.
The HTTP response codes are equivalent to statuses in other protocols that have the same basic meanings. For example, a "file not found" error is equivalent to a 404 code, a server error is equivalent to a 5xx code, and so on.
The HTTP headers are equivalent to fields in other protocols that have the same basic meaning. For example, the HTTP authentication headers are equivalent to the authentication aspects of the FTP protocol.
Status: Last call for comments
Anything in this specification that refers to HTTP also applies
to HTTP-over-TLS, as represented by URLs
representing the https
scheme.
User agents should report certificate errors to the user and must either refuse to download resources sent with erroneous certificates or must act as if such resources were in fact served with no encryption.
User agents should warn the user that there is a potential problem whenever the user visits a page that the user has previously visited, if the page uses less secure encryption on the second visit.
Not doing so can result in users not noticing man-in-the-middle attacks.
If a user connects to a server with a self-signed certificate, the user agent could allow the connection but just act as if there had been no encryption. If the user agent instead allowed the user to override the problem and then displayed the page as if it was fully and safely encrypted, the user could be easily tricked into accepting man-in-the-middle connections.
If a user connects to a server with full encryption, but the page then refers to an external resource that has an expired certificate, then the user agent will act as if the resource was unavailable, possibly also reporting the problem to the user. If the user agent instead allowed the resource to be used, then an attacker could just look for "secure" sites that used resources from a different host and only apply man-in-the-middle attacks to that host, for example taking over scripts in the page.
If a user bookmarks a site that uses a CA-signed certificate, and then later revisits that site directly but the site has started using a self-signed certificate, the user agent could warn the user that a man-in-the-middle attack is likely underway, instead of simply acting as if the page was not encrypted.
Status: Last call for comments. ISSUE-104 (sniffing-optional) blocks progress to Last Call
The Content-Type metadata of a resource must be obtained and interpreted in a manner consistent with the requirements of the Content-Type Processing Model specification. [MIMESNIFF]
The algorithm for extracting an encoding from a Content-Type, given a string s, is given in the Content-Type Processing Model specification. It either returns an encoding or nothing. [MIMESNIFF]
The sniffed type of a resource must be found in a manner consistent with the requirements given in the Content-Type Processing Model specification for finding that sniffed type. [MIMESNIFF]
The rules for sniffing images specifically and the rules for distingushing if a resource is text or binary are also defined in the Content-Type Processing Model specification. Both sets of rules return a MIME type as their result. [MIMESNIFF]
It is imperative that the rules in the Content-Type Processing Model specification be followed exactly. When a user agent uses different heuristics for content type detection than the server expects, security problems can occur. For more details, see the Content-Type Processing Model specification. [MIMESNIFF]
Status: Last call for comments
Status: Last call for comments
Some IDL attributes are defined to reflect a particular content attribute. This means that on getting, the IDL attribute returns the current value of the content attribute, and on setting, the IDL attribute changes the value of the content attribute to the given value.
In general, on getting, if the content attribute is not present, the IDL attribute must act as if the content attribute's value is the empty string; and on setting, if the content attribute is not present, it must first be added.
If a reflecting IDL attribute is a DOMString
attribute whose content attribute is defined to contain a
URL, then on getting, the IDL attribute must resolve the value of the content
attribute relative to the element and return the resulting
absolute URL if that was successful, or the empty
string otherwise; and on setting, must set the content attribute to
the specified literal value. If the content attribute is absent, the
IDL attribute must return the default value, if the content
attribute has one, or else the empty string.
If a reflecting IDL attribute is a DOMString
attribute whose content attribute is defined to contain one or more
URLs, then on getting, the IDL attribute
must split the content
attribute on spaces and return the concatenation of resolving each token URL to an
absolute URL relative to the element, with a single
U+0020 SPACE character between each URL, ignoring any tokens that
did not resolve successfully. If the content attribute is absent,
the IDL attribute must return the default value, if the content
attribute has one, or else the empty string. On setting, the IDL
attribute must set the content attribute to the specified literal
value.
If a reflecting IDL attribute is a DOMString
whose
content attribute is an enumerated attribute, and the
IDL attribute is limited to only known values, then, on
getting, the IDL attribute must return the conforming value
associated with the state the attribute is in (in its canonical
case), or the empty string if the attribute is in a state that has
no associated keyword value; and on setting, if the new value is an
ASCII case-insensitive match for one of the keywords
given for that attribute, then the content attribute must be set to
the conforming value associated with the state that the attribute
would be in if set to the given new value, otherwise, if the new
value is the empty string, then the content attribute must be
removed, otherwise, the setter must raise a SYNTAX_ERR
exception.
If a reflecting IDL attribute is a DOMString
but
doesn't fall into any of the above categories, then the getting and
setting must be done in a transparent, case-preserving manner.
If a reflecting IDL attribute is a boolean attribute, then on getting the IDL attribute must return true if the attribute is set, and false if it is absent. On setting, the content attribute must be removed if the IDL attribute is set to false, and must be set to have the same value as its name if the IDL attribute is set to true. (This corresponds to the rules for boolean content attributes.)
If a reflecting IDL attribute is a signed integer type
(long
) then, on getting, the content attribute must be
parsed according to the rules for parsing signed integers, and if that is
successful, and the value is in the range of the IDL attribute's
type, the resulting value must be returned. If, on the other hand,
it fails or returns an out of range value, or if the attribute is
absent, then the default value must be returned instead, or 0 if
there is no default value. On setting, the given value must be
converted to the shortest possible string representing the number as
a valid integer and then that string must be used as
the new content attribute value.
If a reflecting IDL attribute is a signed integer type
(long
) that is limited to only non-negative
numbers then, on getting, the content attribute must be parsed
according to the rules for parsing non-negative
integers, and if that is successful, and the value is in the
range of the IDL attribute's type, the resulting value must be
returned. If, on the other hand, it fails or returns an out of range
value, or if the attribute is absent, the default value must be
returned instead, or −1 if there is no default value. On
setting, if the value is negative, the user agent must fire an
INDEX_SIZE_ERR
exception. Otherwise, the given value
must be converted to the shortest possible string representing the
number as a valid non-negative integer and then that
string must be used as the new content attribute value.
If a reflecting IDL attribute is an unsigned integer
type (unsigned long
) then, on getting, the content
attribute must be parsed according to the rules for parsing
non-negative integers, and if that is successful, and the
value is in the range of the IDL attribute's type, the resulting
value must be returned. If, on the other hand, it fails or returns
an out of range value, or if the attribute is absent, the default
value must be returned instead, or 0 if there is no default
value. On setting, the given value must be converted to the shortest
possible string representing the number as a valid
non-negative integer and then that string must be used as the
new content attribute value.
If a reflecting IDL attribute is an unsigned integer type
(unsigned long
) that is limited to only
non-negative numbers greater than zero, then the behavior is
similar to the previous case, but zero is not allowed. On getting,
the content attribute must first be parsed according to the
rules for parsing non-negative integers, and if that is
successful, and the value is in the range of the IDL attribute's
type, the resulting value must be returned. If, on the other hand,
it fails or returns an out of range value, or if the attribute is
absent, the default value must be returned instead, or 1 if there is
no default value. On setting, if the value is zero, the user agent
must fire an INDEX_SIZE_ERR
exception. Otherwise, the
given value must be converted to the shortest possible string
representing the number as a valid non-negative integer
and then that string must be used as the new content attribute
value.
If a reflecting IDL attribute is a floating point number type
(float
), then, on getting, the content attribute must
be parsed according to the rules for parsing floating point
number values, and if that is successful, the resulting value
must be returned. If, on the other hand, it fails, or if the
attribute is absent, the default value must be returned instead, or
0.0 if there is no default value. On setting, the given value must
be converted to the best representation of the number as a
floating point number and then that string must be used as
the new content attribute value.
The values Infinity and Not-a-Number (NaN) values throw an exception on setting, as defined earlier.
If a reflecting IDL attribute is of the type
DOMTokenList
or DOMSettableTokenList
, then
on getting it must return a DOMTokenList
or
DOMSettableTokenList
object (as appropriate) whose
underlying string is the element's corresponding content
attribute. When the object mutates its underlying string, the
content attribute must itself be immediately mutated. When the
attribute is absent, then the string represented by the object is
the empty string; when the object mutates this empty string, the
user agent must add the corresponding content attribute, with its
value set to the value it would have been set to after mutating the
empty string. The same DOMTokenList
or
DOMSettableTokenList
object must be returned every time
for each attribute.
If an element with no attributes has its element.classList.remove()
method invoked, the underlying string won't be changed, since the
result of removing any token from the empty string is still the
empty string. However, if the element.classList.add()
method is
then invoked, a class
attribute
will be added to the element with the value of the token to be
added.
If a reflecting IDL attribute has the type
HTMLElement
, or an interface that descends from
HTMLElement
, then, on getting, it must run the
following algorithm (stopping at the first point where a value is
returned):
document.getElementById()
method would find if it
was passed as its argument the current value of the corresponding
content attribute.On setting, if the given element has an id
attribute, then the content attribute must
be set to the value of that id
attribute. Otherwise, the IDL attribute must be set to the empty
string.
Status: Last call for comments
The HTMLCollection
, HTMLAllCollection
,
HTMLFormControlsCollection
,
HTMLOptionsCollection
, and
HTMLPropertiesCollection
interfaces represent various
lists of DOM nodes. Collectively, objects implementing these
interfaces are called collections.
When a collection is created, a filter and a root are associated with the collection.
For example, when the HTMLCollection
object for the document.images
attribute is
created, it is associated with a filter that selects only
img
elements, and rooted at the root of the
document.
The collection then represents a live view of the subtree rooted at the collection's root, containing only nodes that match the given filter. The view is linear. In the absence of specific requirements to the contrary, the nodes within the collection must be sorted in tree order.
The rows
list is
not in tree order.
An attribute that returns a collection must return the same object every time it is retrieved.
Status: Last call for comments
The HTMLCollection
interface represents a generic
collection of elements.
interface HTMLCollection { readonly attribute unsigned long length; caller getter object item(in unsigned long index); // only returns Element caller getter object namedItem(in DOMString name); // only returns Element };
length
Returns the number of elements in the collection.
item
(index)Returns the item with index index from the collection. The items are sorted in tree order.
Returns null if index is out of range.
namedItem
(name)Returns the first item with ID or name name from the collection.
Returns null if no element with that ID or name could be found.
Only a
, applet
, area
,
embed
, form
, frame
,
frameset
, iframe
, img
, and
object
elements can have a name for the purpose of
this method; their name is given by the value of their name
attribute.
The object's indices of the supported indexed properties are the numbers in the range zero to one less than the number of nodes represented by the collection. If there are no such elements, then there are no supported indexed properties.
The length
attribute must return the number of nodes represented by the
collection.
The item(index)
method must return the indexth node in the collection. If there is no indexth node in the collection, then the method must
return null.
The names of the supported named properties consist
of the values of the name
attributes of each
a
, applet
, area
,
embed
, form
, frame
,
frameset
, iframe
, img
, and
object
element represented by the
collection with a name
attribute, plus
the list of IDs that the elements represented by the
collection have.
The namedItem(key)
method must return the first node
in the collection that matches the following requirements:
a
, applet
,
area
, embed
, form
,
frame
, frameset
, iframe
,
img
, or object
element with a name
attribute equal to key,
or,If no such elements are found, then the method must return null.
Status: Last call for comments
The HTMLAllCollection
interface represents a generic
collection of elements just like
HTMLCollection
, with the exception that its namedItem()
method
returns an HTMLCollection
object when there are
multiple matching elements.
interface HTMLAllCollection : HTMLCollection { // inherits length and item() caller getter object namedItem(in DOMString name); // overrides inherited namedItem() HTMLAllCollection tags(in DOMString tagName); };
length
Returns the number of elements in the collection.
item
(index)Returns the item with index index from the collection. The items are sorted in tree order.
Returns null if index is out of range.
namedItem
(name)namedItem
(name)Returns the item with ID or name name from the collection.
If there are multiple matching items, then an HTMLAllCollection
object containing all those elements is returned.
Returns null if no element with that ID or name could be found.
Only a
, applet
, area
,
embed
, form
, frame
,
frameset
, iframe
, img
, and
object
elements can have a name for the purpose of
this method; their name is given by the value of their name
attribute.
tags
(tagName)Returns a collection that is a filtered view of the current collection, containing only elements with the given tag name.
The object's indices of the supported indexed
properties and names of the supported named
properties are as defined for HTMLCollection
objects.
The namedItem(key)
method must act according to the
following algorithm:
Let collection be an
HTMLAllCollection
object rooted at the same node as
the HTMLAllCollection
object on which the method was
invoked, whose filter matches only only elements that already
match the filter of the HTMLAllCollection
object on
which the method was invoked and that are either:
The tags(tagName)
method must return an
HTMLAllCollection
rooted at the same node as the
HTMLAllCollection
object on which the method was
invoked, whose filter matches only HTML elements whose
local name is the tagName argument and that
already match the filter of the HTMLAllCollection
object on which the method was invoked. In HTML
documents, the argument must first be converted to
ASCII lowercase.
Status: Last call for comments
The HTMLFormControlsCollection
interface represents
a collection of listed elements in form
and fieldset
elements.
interface HTMLFormControlsCollection : HTMLCollection { // inherits length and item() caller getter object namedItem(in DOMString name); // overrides inherited namedItem() }; interface RadioNodeList : NodeList { attribute DOMString value; };
length
Returns the number of elements in the collection.
item
(index)Returns the item with index index from the collection. The items are sorted in tree order.
Returns null if index is out of range.
namedItem
(name)namedItem
(name)Returns the item with ID or name
name from the collection.
If there are multiple matching items, then a RadioNodeList
object containing all those elements is returned.
Returns null if no element with that ID or name
could be found.
Returns the value of the first checked radio button represented by the object.
Can be set, to check the first radio button with the given value represented by the object.
The object's indices of the supported indexed
properties are as defined for HTMLCollection
objects.
The names of the supported named properties consist
of the values of all the id
and name
attributes of all the elements
represented by the collection.
The namedItem(name)
method must act according to the
following algorithm:
id
attribute or a name
attribute equal to name, then return that node and stop the
algorithm.id
attribute or a name
attribute equal to name, then return null and stop the algorithm.RadioNodeList
object
representing a live view of the
HTMLFormControlsCollection
object, further filtered so
that the only nodes in the RadioNodeList
object are
those that have either an id
attribute
or a name
attribute equal to name. The nodes in the RadioNodeList
object must be sorted in tree order.RadioNodeList
object.Members of the RadioNodeList
interface inherited
from the NodeList
interface must behave as they would
on a NodeList
object.
The value
IDL attribute on the RadioNodeList
object, on getting,
must return the value returned by running the following steps:
Let element be the first element in
tree order represented by the
RadioNodeList
object that is an input
element whose type
attribute
is in the Radio Button
state and whose checkedness
is true. Otherwise, let it be null.
If element is null, or if it is an
element with no value
attribute, return the empty string.
Otherwise, return the value of element's
value
attribute.
On setting, the value
IDL attribute must run
the following steps:
Let element be the first element in
tree order represented by the
RadioNodeList
object that is an input
element whose type
attribute
is in the Radio Button
state and whose value
content
attribute is present and equal to the new value, if any. Otherwise,
let it be null.
If element is not null, then set its checkedness to true.
Status: Last call for comments
The HTMLOptionsCollection
interface represents a
list of option
elements. It is always rooted on a
select
element and has attributes and methods that
manipulate that element's descendants.
interface HTMLOptionsCollection : HTMLCollection { // inherits item() attribute unsigned long length; // overrides inherited length caller getter object namedItem(in DOMString name); // overrides inherited namedItem() void add(in HTMLElement element, in optional HTMLElement before); void add(in HTMLElement element, in long before); void remove(in long index); };
length
[ = value ]Returns the number of elements in the collection.
When set to a smaller number, truncates the number of option
elements in the corresponding container.
When set to a greater number, adds new blank option
elements to that container.
item
(index)Returns the item with index index from the collection. The items are sorted in tree order.
Returns null if index is out of range.
namedItem
(name)namedItem
(name)Returns the item with ID or name
name from the collection.
If there are multiple matching items, then a NodeList
object containing all those elements is returned.
Returns null if no element with that ID could be found.
add
(element [, before ] )Inserts element before the node given by before.
The before argument can be a number, in which case element is inserted before the item with that number, or an element from the collection, in which case element is inserted before that element.
If before is omitted, null, or a number out of range, then element will be added at the end of the list.
This method will throw a HIERARCHY_REQUEST_ERR
exception if element is an ancestor of the
element into which it is to be inserted. If element is not an option
or
optgroup
element, then the method does nothing.
The object's indices of the supported indexed
properties are as defined for HTMLCollection
objects.
On getting, the length
attribute must return the number of nodes represented by the
collection.
On setting, the behavior depends on whether the new value is
equal to, greater than, or less than the number of nodes
represented by the collection at that time. If the
number is the same, then setting the attribute must do nothing. If
the new value is greater, then n new
option
elements with no attributes and no child nodes
must be appended to the select
element on which the
HTMLOptionsCollection
is rooted, where n is the difference between the two numbers (new
value minus old value). Mutation events must be fired as if a
DocumentFragment
containing the new option
elements had been inserted. If the new value is lower, then the
last n nodes in the collection must be removed
from their parent nodes, where n is the
difference between the two numbers (old value minus new value).
Setting length
never removes
or adds any optgroup
elements, and never adds new
children to existing optgroup
elements (though it can
remove children from them).
The names of the supported named properties consist
of the values of all the id
and name
attributes of all the elements
represented by the collection.
The namedItem(name)
method must act according to the
following algorithm:
id
attribute or a name
attribute equal to name, then return that node and stop the
algorithm.id
attribute or a name
attribute equal to name, then return null and stop the algorithm.NodeList
object representing a
live view of the HTMLOptionsCollection
object, further
filtered so that the only nodes in the NodeList
object
are those that have either an id
attribute or a name
attribute
equal to name. The nodes in the
NodeList
object must be sorted in tree
order.NodeList
object.The add(element, before)
method must act according to the following algorithm:
If element is not an option
or optgroup
element, then return and abort these
steps.
If element is an ancestor of the
select
element on which the
HTMLOptionsCollection
is rooted, then throw a
HIERARCHY_REQUEST_ERR
exception.
If before is an element, but that
element isn't a descendant of the select
element on
which the HTMLOptionsCollection
is rooted, then throw
a NOT_FOUND_ERR
exception.
If element and before are the same element, then return and abort these steps.
If before is a node, then let reference be that node. Otherwise, if before is an integer, and there is a beforeth node in the collection, let reference be that node. Otherwise, let reference be null.
If reference is not null, let parent be the parent node of reference. Otherwise, let parent
be the select
element on which the
HTMLOptionsCollection
is rooted.
Act as if the DOM Core insertBefore()
method was invoked
on the parent node, with element as the first argument and reference as the second argument.
The remove(index)
method must act according to
the following algorithm:
If the number of nodes represented by the collection is zero, abort these steps.
If index is not a number greater than or equal to 0 and less than the number of nodes represented by the collection, let element be the first element in the collection. Otherwise, let element be the indexth element in the collection.
Remove element from its parent node.
Status: Last call for comments
The DOMTokenList
interface represents an interface
to an underlying string that consists of a set of
space-separated tokens.
DOMTokenList
objects are always
case-sensitive, even when the underlying string might
ordinarily be treated in a case-insensitive manner.
interface DOMTokenList { readonly attribute unsigned long length; getter DOMString item(in unsigned long index); boolean contains(in DOMString token); void add(in DOMString token); void remove(in DOMString token); boolean toggle(in DOMString token); stringifier DOMString (); };
length
Returns the number of tokens in the string.
item
(index)Returns the token with index index. The tokens are returned in the order they are found in the underlying string.
Returns null if index is out of range.
contains
(token)Returns true if the token is present; false otherwise.
Throws a SYNTAX_ERR
exception if token is empty.
Throws an INVALID_CHARACTER_ERR
exception if token contains any spaces.
add
(token)Adds token, unless it is already present.
Throws a SYNTAX_ERR
exception if token is empty.
Throws an INVALID_CHARACTER_ERR
exception if token contains any spaces.
remove
(token)Removes token if it is present.
Throws a SYNTAX_ERR
exception if token is empty.
Throws an INVALID_CHARACTER_ERR
exception if token contains any spaces.
toggle
(token)Adds token if it is not present, or removes it if it is. Returns true if token is now present (it was added); returns false if it is not (it was removed).
Throws a SYNTAX_ERR
exception if token is empty.
Throws an INVALID_CHARACTER_ERR
exception if token contains any spaces.
The length
attribute must return the number of tokens that result from splitting the underlying string on
spaces. This is the length.
The object's indices of the supported indexed properties are the numbers in the range zero to length-1, unless the length is zero, in which case there are no supported indexed properties.
The item(index)
method must split the underlying string on spaces,
preserving the order of the tokens as found in the underlying
string, and then return the indexth item in this
list. If index is equal to or greater than the
number of tokens, then the method must return null.
For example, if the string is "a b
a c
" then there are four tokens: the token with index 0 is
"a
", the token with index 1 is "b
", the token with index 2 is "a
", and the token with index 3 is "c
".
The contains(token)
method must run the following
algorithm:
SYNTAX_ERR
exception and stop the
algorithm.INVALID_CHARACTER_ERR
exception and stop the
algorithm.The add(token)
method must run the following
algorithm:
SYNTAX_ERR
exception and stop the
algorithm.INVALID_CHARACTER_ERR
exception and stop the
algorithm.DOMTokenList
object's underlying string then stop the
algorithm.DOMTokenList
object's underlying
string is not the empty string and the last character of that
string is not a space character, then append a U+0020
SPACE character to the end of that string.DOMTokenList
object's underlying string.The remove(token)
method must run the following
algorithm:
SYNTAX_ERR
exception and stop the
algorithm.INVALID_CHARACTER_ERR
exception and stop the
algorithm.The toggle(token)
method must run the following
algorithm:
SYNTAX_ERR
exception and stop the
algorithm.INVALID_CHARACTER_ERR
exception and stop the
algorithm.DOMTokenList
object's underlying string then remove the given token from the underlying string and stop the
algorithm, returning false.DOMTokenList
object's underlying
string is not the empty string and the last character of that
string is not a space character, then append a U+0020
SPACE character to the end of that string.DOMTokenList
object's underlying string.Objects implementing the DOMTokenList
interface must
stringify to the object's
underlying string representation.
Status: Last call for comments
The DOMSettableTokenList
interface is the same as the
DOMTokenList
interface, except that it allows the
underlying string to be directly changed.
interface DOMSettableTokenList : DOMTokenList { attribute DOMString value; };
value
Returns the underlying string.
Can be set, to change the underlying string.
An object implementing the DOMSettableTokenList
interface must act as defined for the DOMTokenList
interface, except for the value
attribute defined
here.
The value
attribute must return the underlying string on getting, and must
replace the underlying string with the new value on setting.
Status: Last call for comments
When a user agent is required to obtain a structured clone of an object, it must run the following algorithm, which either returns a separate object, or throws an exception.
Let input be the object being cloned.
Let memory be a list of objects, initially empty. (This is used to catch cycles.)
Let output be the object resulting from calling the internal structured cloning algorithm with input and memory.
Return output.
The internal structured cloning algorithm is always called with two arguments, input and memory, and its behavior depends on the type of input, as follows:
Return the undefined value.
Return the null value.
Return the false value.
Return the true value.
Return a newly constructed Number object with the same value as input.
Return a newly constructed String object with the same value as input.
Date
objectReturn a newly constructed Date
object with the same value as input.
RegExp
objectReturn a newly constructed RegExp
object with the same pattern and flags as input.
The value of the lastIndex
property is not copied.
ImageData
objectReturn a newly constructed ImageData
object
with the same width
and
height
as input, and with a newly constructed
CanvasPixelArray
for its data
attribute, with the same
length
and pixel
values as the input's.
File
objectReturn a newly constructed File
object corresponding to the same underlying data.
Blob
objectReturn a newly constructed Blob
object corresponding to the same underlying data.
FileList
objectReturn a newly constructed FileList
object containing a list of newly constructed File
objects corresponding to the same underlying data as those in input, maintaining their relative order.
Return the null value.
If input is in memory, then throw a
NOT_SUPPORTED_ERR
exception and abort the overall
structured clone algorithm.
Otherwise, let new memory be a list consisting of the items in memory with the addition of input.
Create a new object, output, of the same type as input: either an Array or an Object.
For each enumerable property in input, add a corresponding property to output having the same name, and having a value created from invoking the internal structured cloning algorithm recursively with the value of the property as the "input" argument and new memory as the "memory" argument. The order of the properties in the input and output objects must be the same.
This does not walk the prototype chain.
Return output.
Error
)Return the null value.
Status: Last call for comments
The DOMStringMap
interface represents a set of
name-value pairs. It exposes these using the scripting language's
native mechanisms for property access.
When a DOMStringMap
object is instantiated, it is
associated with three algorithms, one for getting the list of
name-value pairs, one for setting names to certain values, and one
for deleting names.
interface DOMStringMap { getter DOMString (in DOMString name); setter void (in DOMString name, in DOMString value); creator void (in DOMString name, in DOMString value); deleter void (in DOMString name); };
The names of the supported named properties on a
DOMStringMap
object at any instant are the names of
each pair returned from the algorithm for getting the list of
name-value pairs at that instant.
When a DOMStringMap
object is indexed to retrieve a
named property name, the value returned must be
the value component of the name-value pair whose name component is
name in the list returned by the algorithm for
getting the list of name-value pairs.
When a DOMStringMap
object is indexed to create or
modify a named property name with value value, the algorithm for setting names to certain
values must be run, passing name as the name and
the result of converting value to a
DOMString
as the value.
When a DOMStringMap
object is indexed to delete a
named property named name, the algorithm for
deleting names must be run, passing name as the
name.
The DOMStringMap
interface definition
here is only intended for JavaScript environments. Other language
bindings will need to define how DOMStringMap
is to be
implemented for those languages.
The dataset
attribute on
elements exposes the data-*
attributes on the element.
Given the following fragment and elements with similar constructions:
<img class="tower" id="tower5" data-x="12" data-y="5" data-ai="robotarget" data-hp="46" data-ability="flames" src="towers/rocket.png alt="Rocket Tower">
...one could imagine a function splashDamage()
that takes some arguments, the first
of which is the element to process:
function splashDamage(node, x, y, damage) { if (node.classList.contains('tower') && // checking the 'class' attribute node.dataset.x == x && // reading the 'data-x' attribute node.dataset.y == y) { // reading the 'data-y' attribute var hp = parseInt(node.dataset.hp); // reading the 'data-hp' attribute hp = hp - damage; if (hp < 0) { hp = 0; node.dataset.ai = 'dead'; // setting the 'data-ai' attribute delete node.dataset.ability; // removing the 'data-ability' attribute } node.dataset.hp = hp; // setting the 'data-hp' attribute } }
Status: Last call for comments
DOM3 Core defines mechanisms for checking for interface support, and for obtaining implementations of interfaces, using feature strings. [DOMCORE]
Authors are strongly discouraged from using these, as they are notoriously unreliable and imprecise. Authors are encouraged to rely on explicit feature testing or the graceful degradation behavior intrinsic to some of the features in this specification.
For historical reasons, user agents should return the true value
when the hasFeature(feature, version)
method of the DOMImplementation
interface is invoked
with feature set to either "HTML
" or "XHTML
" and version set to either "1.0
" or
"2.0
".
Status: Last call for comments
The following are DOMException
codes. [DOMCORE]
INDEX_SIZE_ERR
DOMSTRING_SIZE_ERR
HIERARCHY_REQUEST_ERR
WRONG_DOCUMENT_ERR
INVALID_CHARACTER_ERR
NO_DATA_ALLOWED_ERR
NO_MODIFICATION_ALLOWED_ERR
NOT_FOUND_ERR
NOT_SUPPORTED_ERR
INUSE_ATTRIBUTE_ERR
INVALID_STATE_ERR
SYNTAX_ERR
INVALID_MODIFICATION_ERR
NAMESPACE_ERR
INVALID_ACCESS_ERR
VALIDATION_ERR
TYPE_MISMATCH_ERR
SECURITY_ERR
NETWORK_ERR
ABORT_ERR
URL_MISMATCH_ERR
QUOTA_EXCEEDED_ERR
PARSE_ERR
SERIALIZE_ERR
Status: Last call for comments
There is an implied strong reference from any IDL attribute that returns a pre-existing object to that object.
Status: Last call for comments
The HTML namespace is: http://www.w3.org/1999/xhtml
The MathML namespace is: http://www.w3.org/1998/Math/MathML
The SVG namespace is: http://www.w3.org/2000/svg
The XLink namespace is: http://www.w3.org/1999/xlink
The XML namespace is: http://www.w3.org/XML/1998/namespace
The XMLNS namespace is: http://www.w3.org/2000/xmlns/
Data mining tools and other user agents that perform operations on content without running scripts, evaluating CSS or XPath expressions, or otherwise exposing the resulting DOM to arbitrary content, may "support namespaces" by just asserting that their DOM node analogues are in certain namespaces, without actually exposing the above strings.