1. Document Object Model Load and Save

1.1 Overview of the Interfaces

The list of interfaces involved with the Loading and Saving XML documents is:

• DOMImplementationLS -- A new DOMImplementation interface that provides the factory methods for creating the objects required for loading and saving.
• DOMParser -- A parser interface.
• DOMInput -- Encapsulate information about the XML document to be loaded.
• DOMResourceResolver -- During loading, provides a way for applications to redirect references to external entities.
• DOMParserFilter -- Provide the ability to examine and optionally remove Element nodes as they are being processed during the parsing of a document.
• DOMSerializer -- An interface for writing out or serializing DOM documents.
• DOMOutput -- Encapsulate information about the XML document to be serialized.
• DOMSerializerFilter -- Provide the ability to examine and optionally remove nodes as they are being processed during the serialization of a document.
• DocumentLS -- Provides a client or browser style interface for loading and saving.
• ElementLS -- Provides a user convenient mechanism by which the children of an element can be serialized to a string, or replaced by the result of parsing a provided string.

1.2 Basic types

To ensure interoperability, this specification specifies the following basic types used in various DOM modules. Even though the DOM uses the basic types in the interfaces, bindings may use different types and normative bindings are only given for Java and ECMAScript in this specification.

1.3 Fundamental interfaces

The interface within this section is considered fundamental, and must be fully implemented by all conforming implementations of the DOM Load and Save module.

A DOM application may use the hasFeature(feature, version) method of the DOMImplementation interface with parameter values "LS" (or "LS-Async") and "3.0" (respectively) to determine whether or not these interfaces are supported by the implementation. In order to fully support them, an implementation must also support the "Core" feature defined in [DOM Level 2 Core].

A DOM application may use the hasFeature(feature, version) method of the DOMImplementation interface with parameter values "LS-Async" and "3.0" (respectively) to determine whether or not the asynchronous mode is supported by the implementation. In order to fully support the asynchronous mode, an implementation must also support the "LS" feature defined in this section.

For additional information about conformance, please see the DOM Level 3 Core specification [DOM Level 3 Core].

Interface DOMImplementationLS

DOMImplementationLS contains the factory methods for creating Load and Save objects.

The expectation is that an instance of the DOMImplementationLS interface can be obtained by using binding-specific casting methods on an instance of the DOMImplementation interface or, if the Document supports the feature "Core" version "3.0" defined in [DOM Level 3 Core], by using the method DOMImplementation.getFeature with parameter values "LS" (or "LS-Async") and "3.0" (respectively).

IDL Definition

interface DOMImplementationLS {

  // DOMImplementationLSMode
  const unsigned short      MODE_SYNCHRONOUS               = 1;
  const unsigned short      MODE_ASYNCHRONOUS              = 2;

  DOMParser          createDOMParser(in unsigned short mode, 
                                     in DOMString schemaType)
                                        raises(DOMException);
  DOMSerializer      createDOMSerializer();
  DOMInput           createDOMInput();
};

Definition group DOMImplementationLSMode

Integer parser mode constants.

Defined Constants

MODE_ASYNCHRONOUS

Create an asynchronous DOMParser.

MODE_SYNCHRONOUS

Create a synchronous DOMParser.

Methods

createDOMInput

Create a new empty input source.

Return Value

DOMInput

The newly created input object.

No Parameters

No Exceptions

createDOMParser

Create a new DOMParser. The newly constructed parser may then be configured by means of its DOMConfiguration object, and used to parse documents by means of its parse method.

Parameters

mode of type unsigned short

The mode argument is either MODE_SYNCHRONOUS or MODE_ASYNCHRONOUS, if mode is MODE_SYNCHRONOUS then the DOMParser that is created will operate in synchronous mode, if it's MODE_ASYNCHRONOUS then the DOMParser that is created will operate in asynchronous mode.

schemaType of type DOMString

An absolute URI representing the type of the schema language used during the load of a Document using the newly created DOMParser. Note that no lexical checking is done on the absolute URI. In order to create a DOMParser for any kind of schema types (i.e. the DOMParser will be free to use any schema found), use the value null.

Note: For W3C XML Schema [XML Schema Part 1], applications must use the value "http://www.w3.org/2001/XMLSchema". For XML DTD [XML 1.0], applications must use the value "http://www.w3.org/TR/REC-xml". Other Schema languages are outside the scope of the W3C and therefore should recommend an absolute URI in order to use this method.

Return Value

DOMParser

The newly created DOMParser object. This DOMParser is either synchronous or asynchronous depending on the value of the mode argument. Note: By default, the newly created DOMParser does not contain a DOMErrorHandler, i.e. the value of the "error-handler" configuration parameter is null. However, implementations may provide a default error handler at creation time. In that case, the initial value of the "error-handler" configuration parameter on the new created DOMParser contains a reference to the default error handler.

Exceptions

DOMException

NOT_SUPPORTED_ERR: Raised if the requested mode or schema type is not supported.

createDOMSerializer

Create a new DOMSerializer object.

Return Value

DOMSerializer

The newly created DOMSerializer object. Note: By default, the newly created DOMSerializer has no DOMErrorHandler, i.e. the value of the "error-handler" configuration parameter is null. However, implementations may provide a default error handler at creation time. In that case, the initial value of the "error-handler" configuration parameter on the new created DOMSerializer contains a reference to the default error handler.

No Parameters

No Exceptions

Interface DOMParser

An interface to an object that is able to build, or augment, a DOM tree from various input sources.

DOMParser provides an API for parsing XML and building the corresponding DOM document structure. A DOMParser instance can be obtained by invoking the DOMImplementationLS.createDOMParser() method.

As specified in [DOM Level 3 Core], when a document is first made available via the DOMParser:

• there is only one Text node for each block of text. The Text nodes are in "normal" form: only structure (e.g. elements, comments, processing instructions, CDATA sections, and entity references) separates Text nodes, i.e., there are neither adjacent nor empty Text nodes.
• it is expected that the value and nodeValue attributes of an Attr node initially return the XML 1.0 normalized value. However, if the parameters "validate-if-schema" and "datatype-normalization" are set to true, depending on the attribute normalization used, the attribute values may differ from the ones obtained by the XML 1.0 attribute normalization. If the parameters data-type-normalization is set to false, the XML 1.0 attribute normalization is guaranteed to occur, and if the attributes list does not contain namespace declarations, the attributes attribute on Element node represents the property [attributes] defined in [XML Information set].

Asynchronous DOMParser objects are expected to also implement the events::EventTarget interface so that event listeners can be registered on asynchronous DOMParser objects.

Events supported by asynchronous DOMParser objects are:

load

The DOMParser finishes to load the document. See also the definition of the LSLoadEvent interface.

progress

The DOMParser signals a progress as a document is parsed. See also the definition of the LSProgressEvent interface.

Note: All events defined in this specification use the namespace URI "http://www.w3.org/2002/DOMLS".

While parsing an input source, errors are reported to the application through the error handler (DOMParser.config's "error-handler" parameter). This specification does in no way try to define all possible errors that can occur while parsing XML, or any other markup, but some common error cases are defined. The types (DOMError.type) of errors and warnings defined by this specification are:

"unsupported-media-type" [fatal]

Raised if the configuration parameter "supported-media-types-only" is set to true and an unsupported media type is encountered.

"unsupported-encoding" [fatal]

Raised if an unsupported encoding is encountered.

"doctype-not-allowed" [fatal]

Raised if the configuration parameter "disallow-doctype" is set to true and a doctype is encountered.

"unknown-character-denormalization" [fatal]

Raised if the configuration parameter "ignore-unknown-character-denormalizations" is set to false and a character is encountered for which the processor cannot determine the normalization properties.

"unbound-namespace-in-entity" [warning]

Raised if the configuration parameter "entities" is set to true and an unbound namespace prefix is encounterd in an entity declaration.

"pi-base-uri-not-preserved" [warning]

Raised if a processing instruction is encoutered in a location where the base URI of the processing instruction can not be preserved.
One example of a case where this warning will be raised is if the configuration parameter "entities" is set to false and the following XML file is parsed:

<!DOCTYPE root [
<!ENTITY e SYSTEM 'subdir/myentity.ent'
]>

<root>
&e;
</root>

And subdir/myentity.ent looks like this:

<one>
  <two/>
</one>
<?pi 3.14159?>
<more/>

In addition to raising the defined errors and warnings, implementations are expected to raise implementation specific errors and warnings for any other error and warning cases such as IO errors (file not found, permission denied,...), XML well-formedness errors, and so on.

IDL Definition

interface DOMParser {
  readonly attribute DOMConfiguration config;
           attribute DOMParserFilter filter;
  readonly attribute boolean         async;
  readonly attribute boolean         busy;
  Document           parse(in DOMInput is)
                                        raises(DOMException);
  Document           parseURI(in DOMString uri)
                                        raises(DOMException);

  // ACTION_TYPES
  const unsigned short      ACTION_APPEND_AS_CHILDREN      = 1;
  const unsigned short      ACTION_REPLACE_CHILDREN        = 2;
  const unsigned short      ACTION_INSERT_BEFORE           = 3;
  const unsigned short      ACTION_INSERT_AFTER            = 4;
  const unsigned short      ACTION_REPLACE                 = 5;

  Node               parseWithContext(in DOMInput input, 
                                      in Node context, 
                                      in unsigned short action)
                                        raises(DOMException);
  void               abort();
};

Definition group ACTION_TYPES

A set of possible actions for the parseWithContext method.

Defined Constants

ACTION_APPEND_AS_CHILDREN

Append the result of the parse operation as children of the context node. For this action to work, the context node must be an Element or a DocumentFragment.

ACTION_INSERT_AFTER

Insert the result of the parse operation as the immediately following sibling of the context node. For this action to work the context node's parent must be an Element or a DocumentFragment.

ACTION_INSERT_BEFORE

Insert the result of the parse operation as the immediately preceding sibling of the context node. For this action to work the context node's parent must be an Element or a DocumentFragment.

ACTION_REPLACE

Replace the context node with the result of the parse operation. For this action to work, the context node must have a parent, and the parent must be an Element or a DocumentFragment.

ACTION_REPLACE_CHILDREN

Replace all the children of the context node with the result of the parse operation. For this action to work, the context node must be an Element, a Document, or a DocumentFragment.

Attributes

async of type boolean, readonly

true if the DOMParser is asynchronous, false if it is synchronous.

busy of type boolean, readonly

true if the DOMParser is currently busy loading a document, otherwise false.

config of type DOMConfiguration, readonly

The DOMConfiguration object used when parsing an input source. This DOMConfiguration is specific to the parse operation and no parameter values from this DOMConfiguration object are passed automatically to the DOMConfiguration object on the Document that is created, or used, by the parse operation. The DOM application is responsible for passing any needed parameter values from this DOMConfiguration object to the DOMConfiguration object referenced by the Document object.
In addition to the parameters recognized in [DOM Level 3 Core], the DOMConfiguration objects for DOMParser adds or modifies the following parameters:

"charset-overrides-xml-encoding"

true

[required] (default)
If a higher level protocol such as HTTP [IETF RFC 2616] provides an indication of the character encoding of the input stream being processed, that will override any encoding specified in the XML declaration or the Text declaration (see also section 4.3.3, "Character Encoding in Entities", in [XML 1.0]). Explicitly setting an encoding in the DOMInput overrides any encoding from the protocol.

false

[required]
The parser ignores any character set encoding information from higher-level protocols.

"disallow-doctype"

true

[optional]
Throw a fatal "doctype-not-allowed" error if a doctype node is found while parsing the document. This is useful when dealing with things like SOAP envelopes where doctype nodes are not allowed.

false

[required] (default)
Allow doctype nodes in the document.

"ignore-unknown-character-denormalizations"

true

[required] (default)
If, while verifying full normalization when [XML 1.1] is supported, a processor encounters characters for which it cannot determine the normalization properties, then the processor will ignore any possible denormalizations caused by these characters.
This parameter is ignored for [XML 1.0].

false

[optional]
Report an fatal "unknown-character-denormalization" error if a character is encountered for which the processor cannot determine the normalization properties.

"infoset"

See the definition of DOMConfiguration for a description of this parameter. Unlike in [DOM Level 3 Core], this parameter will default to true for DOMParser.

"namespaces"

true

[required] (default)
Perform the namespace processing as defined in [XML Namespaces].

false

[optional]
Do not perform the namespace processing.

"supported-media-types-only"

true

[optional]
Check that the media type of the parsed resource is a supported media type. If an unsupported media type is encountered, a fatal error of type "unsupported-media-type" will be raised. The media types defined in [IETF RFC 3023] must always be accepted.

false

[required] (default)
Accept any media type.

The parameter "well-formed" cannot be set to false.

filter of type DOMParserFilter

When a filter is provided, the implementation will call out to the filter as it is constructing the DOM tree structure. The filter can choose to remove elements from the document being constructed, or to terminate the parsing early.
The filter is invoked after the operations requested by the DOMConfiguration parameters have been applied. For example, if "validate" is set to true, the validation is done before invoking the filter.

Methods

abort

Abort the loading of the document that is currently being loaded by the DOMParser. If the DOMParser is currently not busy, a call to this method does nothing.

No Parameters

No Return Value

No Exceptions

parse

Parse an XML document from a resource identified by a DOMInput.

Parameters

is of type DOMInput

The DOMInput from which the source of the document is to be read.

Return Value

Document

If the DOMParser is a synchronous DOMParser, the newly created and populated Document is returned. If the DOMParser is asynchronous, null is returned since the document object may not yet be constructed when this method returns.

Exceptions

DOMException

INVALID_STATE_ERR: Raised if the DOMParser's DOMParser.busy attribute is true.

parseURI

Parse an XML document from a location identified by a URI reference [IETF RFC 2396]. If the URI contains a fragment identifier (see section 4.1 in [IETF RFC 2396]), the behavior is not defined by this specification, future versions of this specification may define the behavior.

Parameters

uri of type DOMString

The location of the XML document to be read.

Return Value

Document

If the DOMParser is a synchronous DOMParser, the newly created and populated Document is returned. If the DOMParser is asynchronous, null is returned since the document object may not yet be constructed when this method returns.

Exceptions

DOMException

INVALID_STATE_ERR: Raised if the DOMParser.busy attribute is true.

parseWithContext

Parse an XML fragment from a resource identified by a DOMInput and insert the content into an existing document at the position specified with the context and action arguments. When parsing the input stream, the context node is used for resolving unbound namespace prefixes. The context node's ownerDocument node (or the node itself if the node of type DOCUMENT_NODE) is used to resolve default attributes and entity references.
As the new data is inserted into the document, at least one mutation event is fired per new immediate child or sibling of the context node.
If the context node is a Document node and the action is ACTION_REPLACE_CHILDREN, then the document that is passed as the context node will be changed such that it's xmlEncoding, documentURI, xmlVersion, actualEncoding, xmlStandalone, and all other such attributes are set to what they would be set to if the input source was parsed using DOMParser.parse().
If the DOMParser is asynchronous then the insertion of the resulting DOM structure is atomic, e.g. the whole structure is inserted only once the whole input stream is completely parsed without errors.
If an error occurs while parsing, the caller is notified through the ErrorHandler instance associated with the "error-handler" parameter of the DOMConfiguration.
When calling parseWithContext, the values of the following configuration parameters will be ignored and their default values will always be used instead: "validate", "validate-if-schema", and "whitespace-in-element-content".

Parameters

input of type DOMInput

The DOMInput from which the source document is to be read. The source document must be an XML fragment, i.e. anything except a complete XML document (except in the case where the context node of type DOCUMENT_NODE, and the action is ACTION_REPLACE_CHILDREN), a DOCTYPE (internal subset), entity declaration(s), notation declaration(s), or XML or text declaration(s).

context of type Node

The node that is used as the context for the data that is being parsed. This node must be a Document node, a DocumentFragment node, or a node of a type that is allowed as a child of an Element node, e.g. it cannot be an Attribute node.

action of type unsigned short

This parameter describes which action should be taken between the new set of nodes being inserted and the existing children of the context node. The set of possible actions is defined in ACTION_TYPES above.

Return Value

Node	Return the node that is the result of the parse operation. If the result is more than one top-level node, the first one is returned.

Exceptions

DOMException

NOT_SUPPORTED_ERR: Raised if the DOMParser doesn't support this method. NO_MODIFICATION_ALLOWED_ERR: Raised if the context node is a read only node. INVALID_STATE_ERR: Raised if the DOMParser.busy attribute is true.

Interface DOMInput

This interface represents an input source for data.

This interface allows an application to encapsulate information about an input source in a single object, which may include a public identifier, a system identifier, a byte stream (possibly with a specified encoding), a base URI, and/or a character stream.

The exact definitions of a byte stream and a character stream are binding dependent.

The application is expected to provide objects that implement this interface whenever such objects are needed. The application can either provide its own objects that implement this interface, or it can use the generic factory method DOMImplementationLS.createDOMInput() to create objects that implement this interface.

The DOMParser will use the DOMInput object to determine how to read data. The DOMParser will look at the different inputs specified in the DOMInput in the following order to know which one to read from, the first one through which data is available will be used:

1. DOMInput.characterStream
2. DOMInput.byteStream
3. DOMInput.stringData
4. DOMInput.systemId
5. DOMInput.publicId

DOMInput objects belong to the application. The DOM implementation will never modify them (though it may make copies and modify the copies, if necessary).

IDL Definition

interface DOMInput {
  // Depending on the language binding in use,
  // this attribute may not be available.
           attribute DOMReader       characterStream;
           attribute DOMInputStream  byteStream;
           attribute DOMString       stringData;
           attribute DOMString       systemId;
           attribute DOMString       encoding;
           attribute DOMString       publicId;
           attribute DOMString       baseURI;
           attribute boolean         certified;
};

Attributes

baseURI of type DOMString

The base URI to be used (see section 5.1.4 in [IETF RFC 2396]) for resolving a relative systemId to an absolute URI.
If, when used, the base URI is itself a relative URI, an empty string, or null, the behavior is implementation dependent.

byteStream of type DOMInputStream

An attribute of a language and binding dependent type that represents a stream of bytes.
If the application knows the character encoding of the byte stream, it should set the encoding attribute. Setting the encoding in this way will override any encoding specified in an XML declaration in the data.

certified of type boolean

If set to true, assume that the input is certified (see section 2.13 in [XML 1.1]) when parsing [XML 1.1].

characterStream of type DOMReader
Depending on the language binding in use, this attribute may not be available.

An attribute of a language and binding dependent type that represents a stream of 16-bit units. The application must encode the stream using UTF-16 (defined in [Unicode] and Amendment 1 of [ISO/IEC 10646]).

encoding of type DOMString

The character encoding, if known. The encoding must be a string acceptable for an XML encoding declaration ([XML 1.0] section 4.3.3 "Character Encoding in Entities").
This attribute has no effect when the application provides a character stream or string data. For other sources of input, an encoding specified by means of this attribute will override any encoding specified in the XML declaration or the Text declaration, or an encoding obtained from a higher level protocol, such as HTTP [IETF RFC 2616].

publicId of type DOMString

The public identifier for this input source. This may be mapped to an input source using an implementation dependent mechanism (such as catalogues or other mappings). The public identifier, if specified, may also be reported as part of the location information when errors are reported.

stringData of type DOMString

String data to parse. If provided, this will always be treated as a sequence of 16-bit units (UTF-16 encoded characters).

systemId of type DOMString

The system identifier, a URI reference [IETF RFC 2396], for this input source. The system identifier is optional if there is a byte stream, a character stream, or string data, but it is still useful to provide one, since the application will use it to resolve any relative URI's and can include it in error messages and warnings (the DOMParser will only attempt to fetch the resource identified by the URI reference only if there is no other input available in the input source).
If the application knows the character encoding of the object pointed to by the system identifier, it can set the encoding using the encoding attribute.
If the system ID is a relative URI reference (see section 5 in [IETF RFC 2396]), the DOM implementation will attempt to resolve the relative URI with the baseURI as the base, if that fails, the behavior is implementation dependent.

Interface DOMResourceResolver

DOMResourceResolver provides a way for applications to redirect references to external resources.

Applications needing to implement custom handling for external resources can implement this interface and register their implementation by setting the resourceResolver attribute of the DOMParser.

The DOMParser will then allow the application to intercept any external entities (including the external DTD subset and external parameter entities) before including them.

Many DOM applications will not need to implement this interface, but it will be especially useful for applications that build XML documents from databases or other specialized input sources, or for applications that use URN's.

Note: DOMResourceResolver is based on the SAX2 [SAX] EntityResolver interface.

IDL Definition

interface DOMResourceResolver {
  DOMInput           resolveResource(in DOMString publicId, 
                                     in DOMString systemId, 
                                     in DOMString baseURI);
};

Methods

resolveResource

Allow the application to resolve external resources.
The DOMParser will call this method before opening any external resource except the top-level document entity (including the external DTD subset, external entities referenced within the DTD, and external entities referenced within the document element); the application may request that the DOMParser resolve the resource itself, that it use an alternative URI, or that it use an entirely different input source.
Application writers can use this method to redirect external system identifiers to secure and/or local URI's, to look up public identifiers in a catalogue, or to read an entity from a database or other input source (including, for example, a dialog box).
If the system identifier is a URI, the DOMParser must resolve it fully before calling this method.

Parameters

publicId of type DOMString

The public identifier of the external entity being referenced, or null if no public identifier was supplied or if the resource is not an entity.

systemId of type DOMString

The system identifier, a URI reference [IETF RFC 2396], of the external resource being referenced.

baseURI of type DOMString

The absolute base URI of the resource being parsed, or null if there is no base URI.

Return Value

DOMInput

A DOMInput object describing the new input source, or null to request that the parser open a regular URI connection to the system identifier.

No Exceptions

Interface DOMParserFilter

DOMParserFilters provide applications the ability to examine nodes as they are being constructed while parsing. As each node is examined, it may be modified or removed, or the entire parse may be terminated early.

At the time any of the filter methods are called by the parser, the owner Document and DOMImplementation objects exist and are accessible. The document element is never passed to the DOMParserFilter methods, i.e. it is not possible to filter out the document element. The Document, DocumentType, Notation, and Entity nodes are not passed to the acceptNode method on the filter.

All validity checking while reading a document occurs on the source document as it appears on the input stream, not on the DOM document as it is built in memory. With filters, the document in memory may be a subset of the document on the stream, and its validity may have been affected by the filtering.

All default content, including default attributes, must be passed to the filter methods.

The DOMParser ignores any exception raised in the filter.

IDL Definition

interface DOMParserFilter {

  // Constants returned by startElement and acceptNode
  const short               FILTER_ACCEPT                  = 1;
  const short               FILTER_REJECT                  = 2;
  const short               FILTER_SKIP                    = 3;
  const short               FILTER_INTERRUPT               = 4;

  unsigned short     startElement(in Element element);
  unsigned short     acceptNode(in Node node);
  readonly attribute unsigned long   whatToShow;
};

Definition group Constants returned by startElement and acceptNode

Constants returned by startElement and acceptNode.

Defined Constants

FILTER_ACCEPT

Accept the node.

FILTER_INTERRUPT

Interrupt the normal processing of the document.

FILTER_REJECT

Reject the node and its children.

FILTER_SKIP

Skip this single node. The children of this node will still be considered.

Attributes

whatToShow of type unsigned long, readonly

Tells the DOMParser what types of nodes to show to the filter. See NodeFilter for definition of the constants. The constants SHOW_ATTRIBUTE, SHOW_DOCUMENT, SHOW_DOCUMENT_TYPE, SHOW_NOTATION, SHOW_ENTITY, and SHOW_DOCUMENT_FRAGMENT are meaningless here, those nodes will never be passed to a DOMParserFilter.
The constants used here are defined in [DOM Level 2 Traversal and Range].

Methods

acceptNode

This method will be called by the parser at the completion of the parsing of each node. The node and all of its descendants will exist and be complete. The parent node will also exist, although it may be incomplete, i.e. it may have additional children that have not yet been parsed. Attribute nodes are never passed to this function.
From within this method, the new node may be freely modified - children may be added or removed, text nodes modified, etc. The state of the rest of the document outside this node is not defined, and the affect of any attempt to navigate to, or to modify any other part of the document is undefined.
For validating parsers, the checks are made on the original document, before any modification by the filter. No validity checks are made on any document modifications made by the filter.
If this new node is rejected, the parser might reuse the new node or any of its descendants.

Parameters

node of type Node

The newly constructed element. At the time this method is called, the element is complete - it has all of its children (and their children, recursively) and attributes, and is attached as a child to its parent.

Return Value

unsigned short

FILTER_ACCEPT if this Node should be included in the DOM document being built. FILTER_REJECT if the Node and all of its children should be rejected. FILTER_SKIP if the Node should be skipped and the Node should be replaced by all the children of the Node. FILTER_INTERRUPT if the filter wants to stop the processing of the document. Interrupting the processing of the document does no longer guarantee that the entire is XML well-formed.

No Exceptions

startElement

The parser will call this method after each Element start tag has been scanned, but before the remainder of the Element is processed. The intent is to allow the element, including any children, to be efficiently skipped. Note that only element nodes are passed to the startElement function.
The element node passed to startElement for filtering will include all of the Element's attributes, but none of the children nodes. The Element may not yet be in place in the document being constructed (it may not have a parent node.)
A startElement filter function may access or change the attributes for the Element. Changing Namespace declarations will have no effect on namespace resolution by the parser.
For efficiency, the Element node passed to the filter may not be the same one as is actually placed in the tree if the node is accepted. And the actual node (node object identity) may be reused during the process of reading in and filtering a document.

Parameters

element of type Element

The newly encountered element. At the time this method is called, the element is incomplete - it will have its attributes, but no children.

Return Value

unsigned short

FILTER_ACCEPT if this Element should be included in the DOM document being built. FILTER_REJECT if the Element and all of its children should be rejected. This return value will be ignored if element is the documentElement, the documentElement cannot be rejected. FILTER_SKIP if the Element should be rejected. All of its children are inserted in place of the rejected Element node. This return value will be ignored if element is the documentElement, the documentElement cannot be rejected nor skipped. FILTER_INTERRUPT if the filter wants to stop the processing of the document. Interrupting the processing of the document does no longer guarantee that the entire is XML well-formed. Returning any other values will result in unspecified behavior.

No Exceptions

Interface LSProgressEvent

This interface represents a progress event object that notifies the application about progress as a document is parsed. It extends the Event interface defined in [DOM Level 3 Events].

IDL Definition

interface LSProgressEvent : events::Event {
  readonly attribute DOMInput        input;
  readonly attribute unsigned long   position;
  readonly attribute unsigned long   totalSize;
};

Attributes

input of type DOMInput, readonly

The input source that is being parsed.

position of type unsigned long, readonly

The current position in the input source, including all external entities and other resources that have been read.

totalSize of type unsigned long, readonly

The total size of the document including all external resources, this number might change as a document is being parsed if references to more external resources are seen.

Interface LSLoadEvent

This interface represents a load event object that signals the completion of a document load.

IDL Definition

interface LSLoadEvent : events::Event {
  readonly attribute Document        newDocument;
  readonly attribute DOMInput        input;
};

Attributes

input of type DOMInput, readonly

The input source that was parsed.

newDocument of type Document, readonly

The document that finished loading.

Interface DOMSerializer

DOMSerializer provides an API for serializing (writing) a DOM document out into XML. The XML data is written to a string or an output stream.

During serialization of XML data, namespace fixup is done as defined in [DOM Level 3 Core], Appendix B. [DOM Level 2 Core] allows empty strings as a real namespace URI. If the namespaceURI of a Node is empty string, the serialization will treat them as null, ignoring the prefix if any.

DOMSerializer accepts any node type for serialization. For nodes of type Document or Entity, well-formed XML will be created when possible (well-formedness is guaranteed if the document or entity comes from a parse operation and is unchanged since it was created). The serialized output for these node types is either as a XML document or an External XML Entity, respectively, and is acceptable input for an XML parser. For all other types of nodes the serialized form is not specified, but should be something useful to a human for debugging or diagnostic purposes.

Within a Document, DocumentFragment, or Entity being serialized, Nodes are processed as follows

• Document nodes are written, including the XML declaration (unless the parameter "xml-declaration" is set to false) and a DTD subset, if one exists in the DOM. Writing a Document node serializes the entire document.
• Entity nodes, when written directly by DOMSerializer.write, outputs the entity expansion but no namespace fixup is done. The resulting output will be valid as an external entity.
• EntityReference nodes are serialized as an entity reference of the form "&entityName;" in the output. Child nodes (the expansion) of the entity reference are ignored.
• CDATA sections containing content characters that cannot be represented in the specified output encoding are handled according to the "split-cdata-sections" parameter.
  If the parameter is set to true, CDATA sections are split, and the unrepresentable characters are serialized as numeric character references in ordinary content. The exact position and number of splits is not specified.
  If the parameter is set to false, unrepresentable characters in a CDATA section are reported as "invalid-data-in-cdata-section" errors. The error is not recoverable - there is no mechanism for supplying alternative characters and continuing with the serialization.
• DocumentFragment nodes are serialized by serializing the children of the document fragment in the order they appear in the document fragment.
• All other node types (Element, Text, etc.) are serialized to their corresponding XML source form.

Note: The serialization of a Node does not always generate a well-formed XML document, i.e. a DOMParser might throw fatal errors when parsing the resulting serialization.

Within the character data of a document (outside of markup), any characters that cannot be represented directly are replaced with character references. Occurrences of '<' and '&' are replaced by the predefined entities &lt; and &amp;. The other predefined entities (&gt;, &apos;, and &quot;) might not be used, except where needed (e.g. using &gt; in cases such as ']]>'). Any characters that cannot be represented directly in the output character encoding are serialized as numeric character references.

To allow attribute values to contain both single and double quotes, the apostrophe or single-quote character (') may be represented as "&apos;", and the double-quote character (") as "&quot;". New line characters and other characters that cannot be represented directly in attribute values in the output character encoding are serialized as a numeric character reference.

Within markup, but outside of attributes, any occurrence of a character that cannot be represented in the output character encoding is reported as an error. An example would be serializing the element <LaCañada/> with encoding="us-ascii".

When requested by setting the parameter "normalize-characters" on DOMSerializer to true, character normalization is performed according to the rules defined in [CharModel] on all data to be serialized, both markup and character data. The character normalization process affects only the data as it is being written; it does not alter the DOM's view of the document after serialization has completed.

When outputting unicode data, whether or not a byte order mark is serialized, or if the output is big-endian or little-endian, is implementation dependent.

Namespaces are fixed up during serialization, the serialization process will verify that namespace declarations, namespace prefixes and the namespace URI's associated with elements and attributes are consistent. If inconsistencies are found, the serialized form of the document will be altered to remove them. The method used for doing the namespace fixup while serializing a document is the algorithm defined in Appendix B.1, "Namespace normalization", of [DOM Level 3 Core].

Any changes made affect only the namespace prefixes and declarations appearing in the serialized data. The DOM's view of the document is not altered by the serialization operation, and does not reflect any changes made to namespace declarations or prefixes in the serialized output.

Issue DOMSerializer-change-DOM:

We may take back what we say in the above paragraph depending on feedback from implementors, but for now the belief is that the DOM's view of the document is not changed during serialization.

While serializing a document, the parameter "discard-default-content" controls whether or not non-specified data is serialized.

While serializing, errors are reported to the application through the error handler (DOMSerializer.config's "error-handler" parameter). This specification does in no way try to define all possible errors that can occur while serializing a DOM node, but some common error cases are defined. The types (DOMError.type) of errors and warnings defined by this specification are:

"invalid-data-in-cdata-section" [fatal]

Raised if the configuration parameter "split-cdata-sections" is set to false and invalid data is encountered in a CDATA section.

"unsupported-encoding" [fatal]

Raised if an unsupported encoding is encountered.

"unbound-namespace-in-entity" [warning]

Raised if the configuration parameter "entities" is set to true and an unbound namespace prefix is encounterd in a referenced entity.

"no-output-specified" [fatal]

Raised when writing to a DOMOutput if no output is specified in the DOMOutput.

In addition to raising the defined errors and warnings, implementations are expected to raise implementation specific errors and warnings for any other error and warning cases such as IO errors (file not found, permission denied,...) and so on.

IDL Definition

interface DOMSerializer {
  readonly attribute DOMConfiguration config;
           attribute DOMString       newLine;
           attribute DOMSerializerFilter filter;
  boolean            write(in Node node, 
                           in DOMOutput destination);
  boolean            writeURI(in Node node, 
                              in DOMString URI);
  DOMString          writeToString(in Node node)
                                        raises(DOMException);
};

Attributes

config of type DOMConfiguration, readonly

The DOMConfiguration object used by the DOMSerializer when serializing a DOM node.
In addition to the parameters recognized in the [DOM Level 3 Core], the DOMConfiguration objects for DOMSerializer adds, or modifies, the following parameters:

"canonical-form"

true

[optional]
This formatting writes the document according to the rules specified in [Canonical XML]. Setting this parameter to true will set the parameter "format-pretty-print" to false.

false

[required] (default)
Do not canonicalize the output.

"discard-default-content"

true

[required] (default)
Use the Attr.specified attribute to decide what attributes should be discarded. Note that some implementations might use whatever information available to the implementation (i.e. XML schema, DTD, the Attr.specified attribute, and so on) to determine what attributes and content to discard if this parameter is set to true.

false

[required]
Keep all attributes and all content.

"format-pretty-print"

true

[optional]
Formatting the output by adding whitespace to produce a pretty-printed, indented, human-readable form. The exact form of the transformations is not specified by this specification. Pretty-printing changes the content of the document and may affect the validity of the document, validating implementations should preserve validity. Setting this parameter to true will set the parameter "canonical-form" to false.

false

[required] (default)
Don't pretty-print the result.

"ignore-unknown-character-denormalizations"

true

[required] (default)
If, while verifying full normalization when [XML 1.1] is supported, a character is encountered for which the normalization properties cannot be determined, then raise a "unknown-character-denormalization" warning (instead of raising an error, if this parameter is not set) and ignore any possible denormalizations caused by these characters.

Issue DOMSerializer-iucd-issue:

IMO it would make sense to move this parameter into the DOM Level 3 Core spec, and the error/warning should be defined there.

false

[optional]
Report an fatal error if a character is encountered for which the processor cannot determine the normalization properties.

"normalize-characters"

This parameter is equivalent to the one defined by DOMConfiguration in [DOM Level 3 Core]. Unlike in the Core, the default value for this parameter is true. While DOM implementations are not required to support fully normalizing the characters in the document according to the rules defined in [CharModel] supplemented by the definitions of relevant constructs from Section 2.13 of [XML 1.1], this parameter must be activated by default if supported.

"xml-declaration"

true

[required] (default)
If a Document, Element, or Entity node is serialized, the XML declaration, or text declaration, should be included. The version (Document.xmlVersion if the document is a Level 3 document, and the version is non-null, otherwise use the value "1.0"), and possibly an encoding (DOMSerializer.encoding, or Document.actualEncoding or Document.xmlEncoding if the document is a Level 3 document) is specified in the serialized XML declaration.

false

[required]
Do not serialize the XML and text declarations. Report a "xml-declaration-needed" warning if this will cause problems (i.e. the serialized data is of an XML version other than [XML 1.0], or an encoding would be needed to be able to re-parse the serialized data).

The parameters "well-formed", "namespaces", and "namespace-declarations" cannot be set to false.

filter of type DOMSerializerFilter

When the application provides a filter, the serializer will call out to the filter before serializing each Node. The filter implementation can choose to remove the node from the stream or to terminate the serialization early.
The filter is invoked before the operations requested by the DOMConfiguration parameters have been applied. For example, CDATA sections are passed to the filter even if "cdata-sections" is set to false.

newLine of type DOMString

The end-of-line sequence of characters to be used in the XML being written out. Any string is supported, but these are the recommended end-of-line sequences (using other character sequences than these recommended ones can result in a document that is either not serializable or not well-formed):

null

Use a default end-of-line sequence. DOM implementations should choose the default to match the usual convention for text files in the environment being used. Implementations must choose a default sequence that matches one of those allowed by section 2.11, "End-of-Line Handling" in [XML 1.0], if the serialized content is XML 1.0 or section 2.11, "End-of-Line Handling" in [XML 1.1], if the serialized content is XML 1.1.

CR

The carriage-return character (#xD).

CR-LF

The carriage-return and line-feed characters (#xD #xA).

LF

The line-feed character (#xA).

The default value for this attribute is null.

Methods

write

Serialize the specified node as described above in the general description of the DOMSerializer interface. The output is written to the supplied DOMOutput.
When writing to a DOMOutput, the encoding is found by looking at the encoding information that is reachable through the DOMOutput and the item to be written (or its owner document) in this order:

1. DOMOutput.encoding,
2. Document.actualEncoding,
3. Document.xmlEncoding.

If no encoding is reachable through the above properties, a default encoding of "UTF-8" will be used.
If the specified encoding is not supported an "unsupported-encoding" error is raised.
If no output is specified in the DOMOutput, a "no-output-specified" error is raised.

Parameters

node of type Node

The node to serialize.

destination of type DOMOutput

The destination for the serialized DOM.

Return Value

boolean

Returns true if node was successfully serialized and false in case the node couldn't be serialized.

No Exceptions

writeToString

Serialize the specified node as described above in the general description of the DOMSerializer interface. The output is written to a DOMString that is returned to the caller (this method completely ignores all the encoding information available).

Parameters

node of type Node

The node to serialize.

Return Value

DOMString

Returns the serialized data, or null in case the node couldn't be serialized.

Exceptions

DOMException

DOMSTRING_SIZE_ERR: Raised if the resulting string is too long to fit in a DOMString.

writeURI

Serialize the specified node as described above in the general description of the DOMSerializer interface. The output is written to the supplied URI.
When writing to a URI, the encoding is found by looking at the encoding information that is reachable through the item to be written (or its owner document) in this order:

1. Document.actualEncoding,
2. Document.xmlEncoding.

If no encoding is reachable through the above properties, a default encoding of "UTF-8" will be used.
If the specified encoding is not supported an "unsupported-encoding" error is raised.

Parameters

node of type Node

The node to serialize.

URI of type DOMString

The URI to write to.

Return Value

boolean

Returns true if node was successfully serialized and false in case the node couldn't be serialized.

No Exceptions

Interface DOMOutput

This interface represents an output destination for data.

This interface allows an application to encapsulate information about an output destination in a single object, which may include a URI, a byte stream (possibly with a specified encoding), a base URI, and/or a character stream.

The exact definitions of a byte stream and a character stream are binding dependent.

The application is expected to provide objects that implement this interface whenever such objects are needed. The application can either provide its own objects that implement this interface, or it can use the generic factory method DOMImplementationLS.createDOMOutput() to create objects that implement this interface.

The DOMSerializer will use the DOMOutput object to determine where to serialize the output to. The DOMSerializer will look at the different outputs specified in the DOMOutput in the following order to know which one to output to, the first one that data can be output to will be used:

1. DOMOutput.characterStream
2. DOMOutput.byteStream
3. DOMOutput.systemId

DOMOutput objects belong to the application. The DOM implementation will never modify them (though it may make copies and modify the copies, if necessary).

IDL Definition

interface DOMOutput {
  // Depending on the language binding in use,
  // this attribute may not be available.
           attribute DOMWriter       characterStream;
           attribute DOMOutputStream byteStream;
           attribute DOMString       systemId;
           attribute DOMString       encoding;
};

Attributes

byteStream of type DOMOutputStream

An attribute of a language and binding dependent type that represents a writable stream of bytes.
If the application knows the character encoding of the byte stream, it should set the encoding attribute. Setting the encoding in this way will override any encoding specified in an XML declaration in the data.

characterStream of type DOMWriter
Depending on the language binding in use, this attribute may not be available.

An attribute of a language and binding dependent type that represents a writable stream to which 16-bit units can be output. The application must encode the stream using UTF-16 (defined in [Unicode] and Amendment 1 of [ISO/IEC 10646]).

encoding of type DOMString

The character encoding, if known. The encoding must be a string acceptable for an XML encoding declaration ([XML 1.0] section 4.3.3 "Character Encoding in Entities").
This attribute has no effect when the application provides a character stream or string data. For other sources of input, an encoding specified by means of this attribute will override any encoding specified in the XML declaration or the Text declaration, or an encoding obtained from a higher level protocol, such as HTTP [IETF RFC 2616].

systemId of type DOMString

The system identifier, a URI reference [IETF RFC 2396], for this output destination.
If the application knows the character encoding of the object pointed to by the system identifier, it can set the encoding using the encoding attribute.
If the system ID is a relative URI reference (see section 5 in [IETF RFC 2396]), the behavior is implementation dependent.

Interface DOMSerializerFilter

DOMSerializerFilters provide applications the ability to examine nodes as they are being serialized and decide what nodes should be serialized or not. The DOMSerializerFilter interface is based on the NodeFilter interface defined in [DOM Level 2 Traversal and Range].

The Document, DocumentType, DocumentFragment, Attr, Notation, and Entity nodes are not passed to the filter.

The result of any attempt to modify a node passed to a DOMSerializerFilter is implementation dependent.

IDL Definition

interface DOMSerializerFilter : traversal::NodeFilter {
  readonly attribute unsigned long   whatToShow;
};

Attributes

whatToShow of type unsigned long, readonly

Tells the DOMSerializer what types of nodes to show to the filter. See NodeFilter for definition of the constants. The constants SHOW_ATTRIBUTE, SHOW_DOCUMENT, SHOW_DOCUMENT_TYPE, SHOW_NOTATION, SHOW_ATTRIBUTE, and SHOW_DOCUMENT_FRAGMENT are meaningless here, those nodes will never be passed to a DOMSerializerFilter.
The constants used here are defined in [DOM Level 2 Traversal and Range].

1.4 Convenience Interfaces

The interfaces defined in this section provide no direct functionality that cannot be achieved with the load and save interfaces defined in the earlier sections of this specification. These interfaces are defined for developer convenience only, and supporting them is optional.

These interfaces are not nearly as flexible as the ones defined earlier in this specification, for example, no configuration parameters are settable when calling these methods, and the values of all configuration parameters are predefined.

Interface DocumentLS

The DocumentLS interface provides a mechanism by which the content of a document can be serialized, or replaced with the DOM tree produced when loading a URI, or parsing a string.

If the DocumentLS interface is supported, the expectation is that an instance of the DocumentLS interface can be obtained by using binding-specific casting methods on an instance of the Document interface, or by using the method Node.getFeature with parameter values "DocumentLS" and "3.0" (respectively) on an Document, if the Document supports the feature "Core" version "3.0" defined in [DOM Level 3 Core]

This interface is optional. If supported, implementations must support version "3.0" of the feature "DocumentLS".

IDL Definition

interface DocumentLS {
           attribute boolean         async;
                                        // raises(DOMException) on setting

  void               abort();
  boolean            load(in DOMString uri);
  boolean            loadXML(in DOMString source);
  DOMString          saveXML(in Node node)
                                        raises(DOMException);
};

Attributes

async of type boolean

Indicates whether the method DocumentLS.load() should be synchronous or asynchronous. When the async attribute is set to true the load method returns control to the caller before the document has completed loading. The default value of this attribute is true.

Exceptions on setting

DOMException

NOT_SUPPORTED_ERR: Raised if the implementation doesn't support the mode the attribute is being set to.

Methods

abort

If the document is currently being loaded as a result of the method load being invoked the loading and parsing is immediately aborted. The possibly partial result of parsing the document is discarded and the document is cleared.

No Parameters

No Return Value

No Exceptions

load

Replaces the content of the document with the result of parsing the given URI. Invoking this method will either block the caller or return to the caller immediately depending on the value of the async attribute. Once the document is fully loaded a "load" event (as defined in [DOM Level 3 Events], except that the Event.targetNode will be the document, not an element) will be dispatched on the document. If an error occurs, an implementation dependent "error" event will be dispatched on the document. If this method is called on a document that is currently loading, the current load is interrupted and the new URI load is initiated.
When invoking this method the parameters used in the DOMParser interface are assumed to have their default values with the exception that the parameters "entities", "normalize-characters", "check-character-normalization" are set to "false".
The result of a call to this method is the same the result of a call to DOMParser.parseWithContext with an input stream referencing the URI that was passed to this call, the document as the context node, and the action ACTION_REPLACE_CHILDREN.

Parameters

uri of type DOMString

The URI reference for the XML file to be loaded. If this is a relative URI, the base URI used by the implementation is implementation dependent.

Return Value

boolean

If async is set to true load returns true if the document load was successfully initiated. If an error occurred when initiating the document load, load returns false. If async is set to false load returns true if the document was successfully loaded and parsed. If an error occurred when either loading or parsing the URI, load returns false.

No Exceptions

loadXML

Replace the content of the document with the result of parsing the input string, this method is always synchronous. This method always parses from a DOMString, which means the data is always UTF-16. All other encoding information is ignored.
The parameters used in the DOMParser interface are assumed to have their default values when invoking this method.
The result of a call to this method is the same the result of a call to DOMParser.parseWithContext with an input stream containing the string passed to this call, the document as the context node, and the action ACTION_REPLACE_CHILDREN.

Parameters

source of type DOMString

A string containing an XML document.

Return Value

boolean

true if parsing the input string succeeded without errors, otherwise false.

No Exceptions

saveXML

Save the document or the given node and all its descendants to a string (i.e. serialize the document or node).
The parameters used in the DOMSerializer interface are assumed to have their default values when invoking this method.
The result of a call to this method is the same the result of a call to DOMSerializer.writeToString with the document as the node to write.

Parameters

node of type Node

Specifies what to serialize, if this parameter is null the whole document is serialized, if it's non-null the given node is serialized.

Return Value

DOMString

The serialized document or null in case an error occurred.

Exceptions

DOMException

WRONG_DOCUMENT_ERR: Raised if the node passed in as the node parameter is from an other document.

Interface ElementLS

The ElementLS interface provides a convenient mechanism by which the children of an element can be serialized to a string, or replaced by the result of parsing a provided string.

If the ElementLS interface is supported, the expectation is that an instance of the ElementLS interface can be obtained by using binding-specific casting methods on an instance of the Element interface, or by using the method Node.getFeature with parameter values "ElementLS" and "3.0" (respectively) on an Element, if the Element supports the feature "Core" version "3.0" defined in [DOM Level 3 Core].

This interface is optional. If supported, implementations must support version "3.0" of the feature "ElementLS".

IDL Definition

interface ElementLS {
           attribute DOMString       markupContent;
};

Attributes

markupContent of type DOMString

The content of the element in serialized form.
When getting the value of this attribute, the children are serialized in document order and the serialized result is returned. This is equivalent of calling DOMSerializer.writeToString() on all children in document order and appending the result of the individual results to a single string that is then returned as the value of this attribute.
When setting the value of this attribute, all children of the element are removed, the provided string is parsed and the result of the parse operation is inserted into the element. This is equivalent of calling DOMParser.parseWithContext() passing in the provided string (through the input source argument), the Element, and the action ACTION_REPLACE_CHILDREN. If an error occurs while parsing the provided string, the Element's owner document's error handler will be called, and the Element is left with no children.
Both setting and getting the value of this attribute assumes that the parameters in the DOMConfiguration object have their default values.