2. Document Object Model Load and Save

2.1. Load and Save Requirements

DOM Level 3 will provide an API for loading XML documents into a DOM representation and for saving a DOM representation as a XML document.

Some environments, such as the Java [Java] or COM [COM], have their own ways to persist objects to streams and to restore them. There is no direct relationship between these mechanisms and the DOM load/save mechanism. This specification defines how to serialize documents only to and from XML format.

2.2. Issue List

2.3. Interfaces

This section defines an API for loading (parsing) XML documents [XML 1.0] into a DOM representation [DOM Level 3 Core] and for saving (serializing) a DOM representation as an XML document.

The proposal for loading is influenced by the Java APIs for XML Processing [JAXP] and by SAX2 [SAX].

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.
• DOMBuilder -- A parser interface.
• DOMInputSource -- Encapsulate information about the XML document to be loaded.
• DOMEntityResolver -- During loading, provides a way for applications to redirect references to external entities.
• DOMBuilderFilter -- Provide the ability to examine and optionally remove Element nodes as they are being processed during the parsing of a document.
• DOMWriter -- An interface for writing out or serializing DOM documents.
• DocumentLS -- Provides a client or browser style interface for loading and saving.
• ParseErrorEvent -- ParseErrorEvent is the event that is fired if there's an error in the XML document being parsed using the methods of DocumentLS.

Interface DOMImplementationLS

DOMImplementationLS contains the factory methods for creating objects that implement the DOMBuilder (parser) and DOMWriter (serializer) interfaces.

An object that implements DOMImplementationLS is obtained by doing a binding specific cast from DOMImplementation to DOMImplementationLS. Implementations supporting the Load and Save feature must implement the DOMImplementationLS interface on whatever object implements the DOMImplementation interface.

IDL Definition

interface DOMImplementationLS {

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

  DOMBuilder         createDOMBuilder(in unsigned short mode)
                                        raises(DOMException);
  DOMWriter          createDOMWriter();
  DOMInputSource     createDOMInputSource();
};

Definition group DOMIMplementationLSMode

An integer indicating which type of mode this is.

Defined Constants

MODE_ASYNCHRONOUS

Create an asynchronous DOMBuilder.

MODE_SYNCHRONOUS

Create a synchronous DOMBuilder.

Methods

createDOMBuilder

Create a new DOMBuilder. The newly constructed parser may then be configured by means of its setFeature method, 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 DOMBuilder that is created will operate in synchronous mode, if it's MODE_ASYNCHRONOUS then the DOMBuilder that is created will operate in asynchronous mode.

Return Value

DOMBuilder

The newly created DOMBuilder object, this DOMBuilder is either synchronous or asynchronous depending on the value of the type argument.

Exceptions

DOMException

Raise a NOT_SUPPORTED_ERR exception if MODE_ASYNCHRONOUS is not supported.

createDOMInputSource

Create a new "empty" DOMInputSource.

Return Value

DOMInputSource

The newly created DOMBuilder object, this DOMBuilder is either synchronous or asynchronous depending on the value of the type argument.

No Parameters

No Exceptions

createDOMWriter

Create a new DOMWriter object. DOMWriters are used to serialize a DOM tree back into an XML document.

Return Value

DOMWriter

The newly created DOMWriter object.

No Parameters

No Exceptions

Interface DOMBuilder

A interface to an object that is able to build a DOM tree from various input sources.

DOMBuilder provides an API for parsing XML documents and building the corresponding DOM document tree. A DOMBuilder instance is obtained from the DOMImplementationLS interface by invoking its createDOMBuildermethod.

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

• there is only one Text node for each block of text. The Text nodes are into "normal" form: only structure (e.g., elements, comments, processing instructions, CDATA sections, and entity references) separates Text nodes, i.e., there are neither adjacent Text nodes 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 features 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 feature datatype-normalization is not set to true, the XML 1.0 attribute normalization is garantee to occur, and if attributes list does not contain namespace declarations, the attributes attribute on Element node represents the property [attributes] defined in [XML Information set] .

  Issue Infoset:

  XML Schemas does not modified the XML attribute normalization but represents their normalized value in an other information item property: [schema normalized value]
  Resolution: XML Schema normalization only occurs if datatype-normalization is set to true.

The Document Object Model Level 3 Load and Save does not provide a way to disable the namespace resolution: Namespaces are always taken into account during loading and saving operations.

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

Events supported by asynchronous DOMBuilder are:

• ls-load: The document that's being loaded is completely parsed, see the definition of LSLoadEvent
• ls-progress: Progress notification, see the definition of LSProgressEvent

DOMBuilders have a number of named features that can be queried or set. The name of DOMBuilder features must be valid XML names. Implementation specific features (extensions) should choose a implementation specific prefix to avoid name collisions.

Even if all features must be recognized by all implementations, being able to set a state (true or false) is not always required. The following list of recognized features indicates the definitions of each feature state, if setting the state to true or false must be supported or is optional and, which state is the default one:

"namespace-declarations"

true

[required] (default)
include the namespace declaration attributes, specified or defaulted from the schema or the DTD, in the DOM document. See also the section Declaring Namespaces in [XML Namespaces].

false

[optional]
discard all namespace declaration attributes. The Namespace prefixes will be retained even if this feature is set to false.

"validation"

true

[optional]
report validation errors (setting true also will force the external-general-entities and external-parameter-entities features to be true.) Also note that the validate-if-schema feature will alter the validation behavior when this feature is set true.

false

[required] (default)
do not report validation errors.

"external-parameter-entities"

true

[required] (default)
load external parameter entities.

false

[optional]
do not load external parameter entities.

default value

true

"external-general-entities"

true

[required] (default)
include all external general (text) entities.

false

[optional]
do not include external general entities.

"external-dtd-subset"

true

[required] (default)
load the external dtd and also all external parameter entities.

false

[optional]
do not load the dtd nor external parameter entities.

"validate-if-schema"

true

[optional]
when both this feature and validation are true, enable validation only if the document being processed has a schema (i.e. XML schema, DTD, any other type of schema, note that this is unrelated to the abstract schema specification). Documents without schemas are parsed without validation.

false

[required] (default)
the validation feature alone controls whether the document is checked for validity. Documents without a schemas are not valid.

"validate-against-dtd"

true

[optional]
Prefere validation against the DTD over any other schema referenced in the XML file.

false

[required] (default)
Let the parser decide what to validate against if there are references to multiple types of schemas.

"datatype-normalization"

true

[required]
Let the (non-DTD) validation process do its datatype normalization that is defined in the used schema language.

Issue normalization-1:

We should define "datatype normalization".

false

[required] (default)
Disable datatype normalization. The XML 1.0 attribute value normalization is garantee to occur in that case.

"create-entity-ref-nodes"

true

[required] (default)
Create EntityReference nodes in the DOM document. It will also set create-entity-nodes to be true.

false

[optional]
omit all EntityReference nodes from the DOM document, putting the entity expansions directly in their place. Text nodes are into "normal" form. EntityReference nodes to non-defined entities will still be created in the DOM document.

"create-entity-nodes"

true

[required] (default)
Create Entity nodes in the DOM document.

false

[optional]
Omit all entity nodes from the DOM document. It will also set create-entity-ref-nodes to false.

"whitespace-in-element-content"

true

[required] (default)
Include white space characters appearing within element content (see [XML 1.0] 2.10 "White Space Handling").

false

[optional]
Omit white space characters appearing within element content. Note that white space characters within element content will only be omitted if it can be identified as such, and not all parsers may be able to do so (see [XML 1.0] 2.10 "White Space Handling").

"create-cdata-nodes"

true

[required] (default)
Create CDATASection nodes in response to the appearance of CDATA sections in the XML document.

false

[optional]
Do not create CDATASection nodes in the DOM document.
The content of any CDATA sections in the XML document appears in the DOM as if it had been normal (non-CDATA) content. If a CDATA section is adjacent to other content, the combined content appears in a single Text node, i.e. the Text nodes are into "normal" form.

"comments"

true

[required] (default)
Include XML comments in the DOM document.

false

[required]
Discard XML comments, do not create Comment nodes in the DOM Document resulting from a parse.

"charset-overrides-xml-encoding"

true

[required] (default)
If a higher level protocol such as HTTP [RFC2616] 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 [XML 1.0] 4.3.3 "Character Encoding in Entities"). Explicitly setting an encoding in the DOMInputSource overrides encodings from the protocol.

false

[required]
Any character set encoding information from higher level protocols is ignored by the parser.

"load-as-infoset"

true

[optional]
Load the document and store only the information defined in the XML Information Set [XML Information set].
This will force the following features to false: namespace-declarations, validate-if-schema, create-entity-ref-nodes, create-entity-nodes, create-cdata-nodes.
This will force the following features to true: datatype-normalization, whitespace-in-element-content, comments, charset-overrides-xml-encoding.
Other features are not changed unless explicity specified in the description of the features.
Note that querying this feature with getFeature will return true only if the individual features specified above are appropriately set.

false

Setting load-as-infoset to false has no effect.

"supported-mediatypes-only"

true

[optional]
Check that the media type of the parsed resource is a supported media type and call the error handler if an unsupported media type is encountered. The media types defined in [RFC3023] must be accepted.

false

[required] (default)
Don't check the media type, accept any type of data.

IDL Definition

interface DOMBuilder {
           attribute DOMEntityResolver entityResolver;
           attribute DOMErrorHandler errorHandler;
           attribute DOMBuilderFilter filter;
  void               setFeature(in DOMString name, 
                                in boolean state)
                                        raises(DOMException);
  boolean            canSetFeature(in DOMString name, 
                                   in boolean state);
  boolean            getFeature(in DOMString name)
                                        raises(DOMException);
  Document           parseURI(in DOMString uri)
                                        raises(DOMSystemException);
  Document           parse(in DOMInputSource is)
                                        raises(DOMSystemException);

  // ACTION_TYPES
  const unsigned short      ACTION_REPLACE                 = 1;
  const unsigned short      ACTION_APPEND                  = 2;
  const unsigned short      ACTION_INSERT_AFTER            = 3;
  const unsigned short      ACTION_INSERT_BEFORE           = 4;

  void               parseWithContext(in DOMInputSource is, 
                                      in Node cnode, 
                                      in unsigned short action)
                                        raises(DOMException);
};

Definition group ACTION_TYPES

A set of possible actions for the parseWithContext method.

Defined Constants

ACTION_APPEND

Append the result of parsing the input source to the context node. For this action to work, the context node must be an Element.

ACTION_INSERT_AFTER

Insert the result of parsing the input source after the context node. For this action to work the context nodes parent must be an Element.

ACTION_INSERT_BEFORE

Insert the result of parsing the input source before the context node. For this action to work the context nodes parent must be an Element.

ACTION_REPLACE

Replace the context node with the result of parsing the input source. For this action to work the context node must be an Element, Text, CDATASection, Comment, ProcessingInstruction, or EntityReference node.

Attributes

entityResolver of type DOMEntityResolver

If a DOMEntityResolver has been specified, each time a reference to an external entity is encountered the DOMBuilder will pass the public and system IDs to the entity resolver, which can then specify the actual source of the entity.

errorHandler of type DOMErrorHandler

In the event that an error is encountered in the XML document being parsed, the DOMDcoumentBuilder will call back to the errorHandler with the error information. When the document loading process calls the error handler the node closest to where the error occured is passed to the error handler if the implementation, if the implementation is unable to pass the node where the error occures the document Node is passed to the error handler. Mutations to the document from within an error handler will result in implementation dependent behavour.

filter of type DOMBuilderFilter

When the application provides a filter, the parser will call out to the filter at the completion of the construction of each Element node. The filter implementation can choose to remove the element from the document being constructed (unless the element is the document element) or to terminate the parse early. If the document is being validated when it's loaded the validation happens before the filter is called.

Methods

canSetFeature

Query whether setting a feature to a specific value is supported.
The feature name has the same form as a DOM hasFeature string.

Parameters

name of type DOMString

The feature name, which is a DOM has-feature style string.

state of type boolean

The requested state of the feature (true or false).

Return Value

boolean

true if the feature could be successfully set to the specified value, or false if the feature is not recognized or the requested value is not supported. The value of the feature itself is not changed.

No Exceptions

getFeature

Look up the value of a feature.
The feature name has the same form as a DOM hasFeature string

Parameters

name of type DOMString

The feature name, which is a string with DOM has-feature syntax.

Return Value

boolean

The current state of the feature (true or false).

Exceptions

DOMException

Raise a NOT_FOUND_ERR When the DOMBuilder does not recognize the feature name.

parse

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

Parameters

is of type DOMInputSource

The DOMInputSource from which the source document is to be read.

Return Value

Document

If the DOMBuilder is a synchronous DOMBuilder the newly created and populated Document is returned. If the DOMBuilder is asynchronous then null is returned since the document object is not yet parsed when this method returns.

Exceptions

DOMSystemException

Exceptions raised by parse originate with the installed ErrorHandler, and thus depend on the implementation of the DOMErrorHandler interfaces. The default ErrorHandlers will raise a DOMSystemException if any form I/O or other system error occurs during the parse, but application defined ErrorHandlers are not required to do so.

parseURI

Parse an XML document from a location identified by an URI reference [RFC2396]. If the URI contains a fragment identifier (see section 4.1 in [RFC2396]), the behavior is not defined by this specification.

Parameters

uri of type DOMString

The location of the XML document to be read.

Return Value

Document

If the DOMBuilder is a synchronous DOMBuilder the newly created and populated Document is returned. If the DOMBuilder is asynchronous then null is returned since the document object is not yet parsed when this method returns.

Exceptions

DOMSystemException

Exceptions raised by parseURI originate with the installed ErrorHandler, and thus depend on the implementation of the DOMErrorHandler interfaces. The default error handlers will raise a DOMSystemException if any form I/O or other system error occurs during the parse, but application defined error handlers are not required to do so.

parseWithContext

Parse an XML document or fragment from a resource identified by an DOMInputSource and insert the content into an existing document at the position epcified with the contextNode and action arguments. When parsing the input stream the context node is used for resolving unbound namespace prefixes.

Parameters

is of type DOMInputSource

The DOMInputSource from which the source document is to be read.

cnode of type Node

The Node that is used as the context for the data that is being parsed.

action of type unsigned short

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

Exceptions

DOMException

HIERARCHY_REQUEST_ERR: Thrown if this action results in an invalid hierarchy (i.e. a Document with more than one document element).

No Return Value

setFeature

Set the state of a feature.
The feature name has the same form as a DOM hasFeature string.
It is possible for a DOMBuilder to recognize a feature name but to be unable to set its value.

Parameters

name of type DOMString

The feature name.

state of type boolean

The requested state of the feature (true or false).

Exceptions

DOMException

Raise a NOT_SUPPORTED_ERR exception when the DOMBuilder recognizes the feature name but cannot set the requested value. Raise a NOT_FOUND_ERR When the DOMBuilder does not recognize the feature name.

No Return Value

Interface DOMWriter

DOMWriter provides an API for serializing (writing) a DOM document out in an XML document. The XML data is written to an output stream, the type of which depends on the specific language bindings in use. During serialization of XML data, namespace fixup is done when possible.

DOMWriter accepts any node type for serialization. For nodes of type Document or Entity, well formed XML will be created if possible. The serialized output for these node types is either as a Document or an External 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. Note: rigorously designing an external (source) form for stand-alone node types that don't already have one defined in [XML 1.0] seems a bit much to take on here.

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

• Documents are written including an XML declaration and a DTD subset, if one exists in the DOM. Writing a document node serializes the entire document.
• Entity nodes, when written directly by writeNode defined in the DOMWriter interface, output the entity expansion but no namespace fixup is done. The resulting output will be valid as an external entity.
• Entity References nodes are serializes 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 can not be represented in the specified output encoding are handled according to the "split-cdata-sections" feature.
  If the feature is 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 feature is false, unrepresentable characters in a CDATA section are reported as errors. The error is not recoverable - there is no mechanism for supplying alternative characters and continuing with the serialization.
• All other node types (Element, Text, etc.) are serialized to their corresponding XML source form.

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, etc.) are not used; these characters can be included directly. Any character that can not be represented directly in the output character encoding is serialized as a numeric character reference.

Attributes not containing quotes are serialized in quotes. Attributes containing quotes but no apostrophes are serialized in apostrophes (single quotes). Attributes containing both forms of quotes are serialized in quotes, with quotes within the value represented by the predefined entity &quot;. Any character that can not be represented directly in the output character encoding is 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 the encoding="us-ascii".

When requested by setting the normalize-characters feature on DOMWriter, all data to be serialized, both markup and character data, is W3C Text normalized according to the rules defined in [CharModel]. The W3C Text 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.

Namespaces are fixed up during serialization, the serialization process will verify that namespace declarations, namespace prefixes and the namespace URIs associated with Elements and Attributes are consistent. If inconsistencies are found, the serialized form of the document will be altered to remove them. The algorithm used for doing the namespace fixup while seralizing a document is a combination of the algorithms used for lookupNamespaceURI and lookupNamespacePrefix .

(ED: previous paragraph to be defined closer here.)

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.

While serializing a document the serializer will write out non-specified values (such as attributes whose specified is false) if the output-default-values feature is set to true. If the output-default-values flag is set to false and the use-abstract-schema feature is set to true the abstract schema will be used to determine if a value is specified or not, if use-abstract-schema is not set the specified flag on attribute nodes is used to determine if attribute values should be written out.

Ref to Core spec (1.1.9, XML namespaces, 5th paragraph) entity ref description about warning about unbound entity refs. Entity refs are always serialized as &foo;, also mention this in the load part of this spec.

When serializing a document the DOMWriter checks to see if the document element in the document is a DOM Level 1 element or a DOM Level 2 (or higher) element (this check is done by looking at the localName of the root element). If the root element is a DOM Level 1 element then the DOMWriter will issue an error if a DOM Level 2 (or higher) element is found while serializing. Likewise if the document element is a DOM Level 2 (or higher) element and the DOMWriter sees a DOM Level 1 element an error is issued. Mixing DOM Level 1 elements with DOM Level 2 (or higher) is not supported.

DOMWriters have a number of named features that can be queried or set. The name of DOMWriter features must be valid XML names. Implementation specific features (extensions) should choose an implementation dependent prefix to avoid name collisions.

Here is a list of properties that must be recognized by all implementations.

"normalize-characters"

true

[optional] (default)
Perform the W3C Text Normalization of the characters [CharModel] in document as they are written out. Only the characters being written are (potentially) altered. The DOM document itself is unchanged.

false

[required]
do not perform character normalization.

"split-cdata-sections"

true

[required] (default)
Split CDATA sections containing the CDATA section termination marker ']]>' or characters that can not be represented in the output encoding, and output the characters using numeric character references. If a CDATA section is split a warning is issued.

false

[required]
Signal an error if a CDATASection contains an unrepresentable character.

"validation"

true

[optional]
Use the abstract schema to validate the document as it is being serialized. If validation errors are found the error handler is notified about the error. Setting this state will also set the feature use-abstract-schema to true.

false

[required] (default)
Don't validate the document as it is being serialized.

"expand-entity-references"

true

[optional]
Expand EntityReference nodes when serializing.

false

[required] (default)
Serialize all EntityReference nodes as XML entity references.

"whitespace-in-element-content"

true

[required] (default)
Output all white spaces in the document.

false

[optional]
Only output white space that is not within element content. The implementation is expected to use the isWhitespaceInElementContent flag on Text nodes to determine if a text node should be written out or not.

"discard-default-content"

true

[required] (default)
Use whatever information available to the implementation (i.e. XML schema, DTD, the specified flag on Attr nodes, and so on) to decide what attributes and content should be serialized or not. Note that the specified flag on Attr nodes in itself is not always reliable, it is only reliable when it is set to false since the only case where it can be set to false is if the attribute was created by a Level 1 implementation.

false

[required]
Output all attributes and all content.

"format-canonical"

true

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

false

[required] (default)
Don't canonicalize the output.

"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. Setting this feature to true will set the feature "format-canonical" to false.

false

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

IDL Definition

interface DOMWriter {
  void               setFeature(in DOMString name, 
                                in boolean state)
                                        raises(DOMException);
  boolean            canSetFeature(in DOMString name, 
                                   in boolean state);
  boolean            getFeature(in DOMString name)
                                        raises(DOMException);
           attribute DOMString       encoding;
  readonly attribute DOMString       lastEncoding;
           attribute DOMString       newLine;
           attribute DOMErrorHandler errorHandler;
  boolean            writeNode(in DOMOutputStream destination, 
                               in Node wnode)
                                        raises(DOMSystemException);
  DOMString          writeToString(in Node wnode)
                                        raises(DOMException);
};

Attributes

encoding of type DOMString

The character encoding in which the output will be written.
The encoding to use when writing is determined as follows:

• If the encoding attribute has been set, that value will be used.
• If the encoding attribute is null or empty, but the item to be written includes an encoding declaration, that value will be used.
• If neither of the above provides an encoding name, a default encoding of "UTF-8" will be used.

The default value is null.

errorHandler of type DOMErrorHandler

The error handler that will receive error notifications during serialization. The node where the error occured is passed to this error handler, any modification to nodes from within an error callback should be avoided since this will result in undefined, implementation dependent behavior.

lastEncoding of type DOMString, readonly

The actual character encoding that was last used by this formatter. This convenience method allows the encoding that was used when serializing a document to be directly obtained.

newLine of type DOMString

The end-of-line sequence of characters to be used in the XML being written out. The only permitted values are these:

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 [XML 1.0] 2.11 "End-of-Line Handling".

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

canSetFeature

Query whether setting a feature to a specific value is supported.
The feature name has the same form as a DOM hasFeature string.

Parameters

name of type DOMString

The feature name, which is a DOM has-feature style string.

state of type boolean

The requested state of the feature (true or false).

Return Value

boolean

true if the feature could be successfully set to the specified value, or false if the feature is not recognized or the requested value is not supported. The value of the feature itself is not changed.

No Exceptions

getFeature

Look up the value of a feature.
The feature name has the same form as a DOM hasFeature string

Parameters

name of type DOMString

The feature name, which is a string with DOM has-feature syntax.

Return Value

boolean

The current state of the feature (true or false).

Exceptions

DOMException

Raise a NOT_FOUND_ERR When the DOMWriter does not recognize the feature name.

setFeature

Set the state of a feature.
The feature name has the same form as a DOM hasFeature string.
It is possible for a DOMWriter to recognize a feature name but to be unable to set its value.

Parameters

name of type DOMString

The feature name.

state of type boolean

The requested state of the feature (true or false).

Exceptions

DOMException

Raise a NOT_SUPPORTED_ERR exception when the DOMWriter recognizes the feature name but cannot set the requested value. Raise a NOT_FOUND_ERR When the DOMWriter does not recognize the feature name.

No Return Value

writeNode

Write out the specified node as described above in the description of DOMWriter. Writing a Document or Entity node produces a serialized form that is well formed XML. Writing other node types produces a fragment of text in a form that is not fully defined by this document, but that should be useful to a human for debugging or diagnostic purposes.

Parameters

destination of type DOMOutputStream

The destination for the data to be written.

wnode of type Node

The Document or Entity node to be written. For other node types, something sensible should be written, but the exact serialized form is not specified.

Return Value

boolean

Returns true if node was successfully serialized and false in case a failure occured and the failure wasn't canceled by the error handler.

Exceptions

DOMSystemException

This exception will be raised in response to any sort of IO or system error that occurs while writing to the destination. It may wrap an underlying system exception.

writeToString

Serialize the specified node as described above in the description of DOMWriter. The result of serializing the node is returned as a string. Writing a Document or Entity node produces a serialized form that is well formed XML. Writing other node types produces a fragment of text in a form that is not fully defined by this document, but that should be useful to a human for debugging or diagnostic purposes.

Parameters

wnode of type Node

The node to be written.

Return Value

DOMString

Returns the serialized data, or null in case a failure occured and the failure wasn't canceled by the error handler.

Exceptions

DOMException

DOMSTRING_SIZE_ERR: The resulting string is too long to fit in a DOMString.

Interface DOMInputSource

This interface represents a single input source for an XML entity.

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), and/or a character stream.

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

There are two places that the application will deliver this input source to the parser: as the argument to the parse method, or as the return value of the DOMEntityResolver.resolveEntity method.

The DOMBuilder will use the DOMInputSource object to determine how to read XML input. If there is a character stream available, the parser will read that stream directly; if not, the parser will use a byte stream, if available; if neither a character stream nor a byte stream is available, the parser will attempt to open a URI connection to the resource identified by the system identifier.

An DOMInputSource object belongs to the application: the parser shall never modify it in any way (it may modify a copy if necessary).

Note: Eventhough all attributes in this interface are writable the DOM implementation is expected to never mutate a DOMInputSource.

IDL Definition

interface DOMInputSource {
           attribute DOMInputSource  byteStream;
           attribute DOMReader       characterStream;
           attribute DOMString       stringData;
           attribute DOMString       encoding;
           attribute DOMString       publicId;
           attribute DOMString       systemId;
           attribute DOMString       baseURI;
};

Attributes

baseURI of type DOMString

The base URI to be used (see section 5.1.4 in [RFC2396]) for resolving relative URIs to absolute URIs. If the baseURI is itself a relative URI, the behavior is implementation dependent.

byteStream of type DOMInputSource

An attribute of a language-binding dependent type that represents a stream of bytes.
The parser will ignore this if there is also a character stream specified, but it will use a byte stream in preference to opening a URI connection itself.
If the application knows the character encoding of the byte stream, it should set the encoding property. Setting the encoding in this way will override any encoding specified in the XML declaration itself.

characterStream of type DOMReader

An attribute of a language-binding dependent type that represents a stream of 16-bit units. Application must encode the stream using UTF-16 (defined in [Unicode 3.0] and Amendment 1 of [ISO/IEC 10646]).
If a character stream is specified, the parser will ignore any byte stream and will not attempt to open a URI connection to the system identifier.

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. For other sources of input, an encoding specified by means of this attribute will override any encoding specified in the XML claration or the Text Declaration, or an encoding obtained from a higher level protocol, such as HTTP [RFC2616].

publicId of type DOMString

The public identifier for this input source. The public identifier is always optional: if the application writer includes one, it will be provided as part of the location information.

stringData of type DOMString

A string attribute that represents a sequence of 16 bit units (utf-16 encoded characters).
If string data is available in the input source, the parser will ignore the character stream and the byte stream and will not attempt to open a URI connection to the system identifier.

systemId of type DOMString

The system identifier, a URI reference [RFC2396], for this input source. The system identifier is optional if there is a byte stream or a character stream, but it is still useful to provide one, since the application can use it to resolve relative URIs and can include it in error messages and warnings (the parser will attempt to fetch the ressource identifier by the URI reference only if there is no byte stream or character stream specified).
If the application knows the character encoding of the object pointed to by the system identifier, it can register the encoding by setting the encoding attribute.
If the system ID is a relative URI reference (see section 5 in [RFC2396]), the behavior is implementation dependent.

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 DOMInputSource  inputSource;
};

Attributes

inputSource of type DOMInputSource, readonly

The input source that was parsed.

newDocument of type Document, readonly

The document that finished loading.

Interface LSProgressEvent

This interface represents a progress event object that notifies the application about progress as a document is parsed. This event is optional and the rate at which this event is fired is implementation dependent.

IDL Definition

interface LSProgressEvent : events::Event {
  readonly attribute DOMInputSource  inputSource;
  readonly attribute unsigned long   position;
  readonly attribute unsigned long   totalSize;
};

Attributes

inputSource of type DOMInputSource, 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 DOMEntityResolver

DOMEntityResolver Provides a way for applications to redirect references to external entities.

Applications needing to implement customized handling for external entities must implement this interface and register their implementation by setting the entityResolver property of the DOMBuilder.

The DOMBuilder 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 URI types other than URIs.

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

IDL Definition

interface DOMEntityResolver {
  DOMInputSource     resolveEntity(in DOMString publicId, 
                                   in DOMString systemId, 
                                   in DOMString baseURI)
                                        raises(DOMSystemException);
};

Methods

resolveEntity

Allow the application to resolve external entities.
The DOMBuilder will call this method before opening any external entity 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 DOMBuilder resolve the entity 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 URIs, 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 DOMBuilder must resolve it fully before reporting it to the application through this interface.

(ED: See issue #4. An alternative would be to pass the URI out without resolving it, and to provide a base as an additional parameter. SAX resolves URIs first, and does not provide a base. )

Parameters

publicId of type DOMString

The public identifier of the external entity being referenced, or null if none was supplied.

systemId of type DOMString

The system identifier, a URI reference [RFC2396], of the external entity being referenced exactly as written in the source (i.e. .

baseURI of type DOMString

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

Return Value

DOMInputSource

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

Exceptions

DOMSystemException

Any DOMSystemException, possibly wrapping another exception.

Interface DOMBuilderFilter

DOMBuilderFilters provide applications the ability to examine nodes as they are being constructed during a parse. 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 DOMBuilderFilter methods, i.e. it is not possible to filter out the document element.

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.

(ED: The description of these methods is not complete)

IDL Definition

interface DOMBuilderFilter {
  unsigned long      startNode(in Node snode);
  unsigned long      endNode(in Node enode);
  readonly attribute unsigned long   whatToShow;
};

Attributes

whatToShow of type unsigned long, readonly

Tells the DOMBuilder what types of nodes to show to the filter. See NodeFilter for definition of the constants. The constant SHOW_ATTRIBUTE is meaningless here, attribute nodes will never be passed to a DOMBuilderFilter.

Methods

endNode

This method will be called by the parser at the completion of the parse of each node. The node will exist and be complete, as will all of its children, and their children, recursively. The parent node will also exist, although that node may be incomplete, as 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. This node may also be removed from its parent node, which will prevent it from appearing in the final document at the completion of the parse. Aside from this one operation on the node's parent, the state of the rest of the document outside of this node is not defined, and the affect of any attempt to navigate to or 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.

Parameters

enode 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 long

ACCEPT if this Node should be included in the DOM document being built. REJECT if the Node and all of its children should be rejected.

No Exceptions

startNode

This method will be called by the parser 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 startNode function.
The element node passed to startNode 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 startNode filter function may access or change the attributers 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

snode of type Node

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

Issue startNode-1:

Should the parameter be an Element since we only passed elements to startNode?

Return Value

unsigned long

ACCEPT if this Element should be included in the DOM document being built. REJECT if the Element and all of its children should be rejected. SKIP if the Element should be rejected. All of its children are inserted in place of the rejected Element node.

No Exceptions

Interface DOMWriterFilter

DOMWriterFilters provide applications the ability to examine nodes as they are being serialized. DOMWriterFilter lets the application decide what nodes should be serialized or not.

IDL Definition

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

Attributes

whatToShow of type unsigned long, readonly

Tells the DOMWriter what types of nodes to show to the filter. See NodeFilter for definition of the constants. The constant SHOW_ATTRIBUTE is meaningless here, attribute nodes will never be passed to a DOMWriterFilter.

Interface DocumentLS

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

uses the default features.

IDL Definition

interface DocumentLS {
           attribute boolean         async;
  void               abort();
  boolean            load(in DOMString uri);
  boolean            loadXML(in DOMString source);
  DOMString          saveXML(in Node snode)
                                        raises(DOMException);
};

Attributes

async of type boolean

Indicates whether the method 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 property is false.
Setting the value of this attribute might throw NOT_SUPPORTED_ERR if the implementation doesn't support the mode the attribute is being set to.

Issue async-1:

Should the DOM spec define the default value of this property? What if implementing both async and sync IO is impractical in some systems?
Resolution: 2001-09-14. default is false but we need to check with Mozilla and IE.

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 the document will fire a "load" event that the caller can register as a listener for. If an error occurs the document will fire an "error" event so that the caller knows that the load failed (see ParseErrorEvent).

Parameters

uri of type DOMString

The URI reference for the XML file to be loaded. If this is a relative URI...

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.

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 to a string (i.e. serialize the document or node).

Parameters

snode 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.

Exceptions

DOMException

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

Interface ParseErrorEvent

ParseErrorEvent is the event that is fired if there's an error in the XML document being parsed.

IDL Definition

interface ParseErrorEvent : events::Event {
  readonly attribute DOMError        error;
};

Attributes

error of type DOMError, readonly

An non-zero implementation dependent error code describing the error, or 0 if there is no error.