The Attr interface represents an attribute in an Element object. Typically the allowable values for the attribute are defined in a schema associated with the document.

Attr objects inherit the Node interface, but since they are not actually child nodes of the element they describe, the DOM does not consider them part of the document tree. Thus, the Node attributes parentNode, previousSibling, and nextSibling have a null value for Attr objects. The DOM takes the view that attributes are properties of elements rather than having a separate identity from the elements they are associated with; this should make it more efficient to implement such features as default attributes associated with all elements of a given type. Furthermore, Attr nodes may not be immediate children of a DocumentFragment. However, they can be associated with Element nodes contained within a DocumentFragment. In short, users and implementors of the DOM need to be aware that Attr nodes have some things in common with other objects inheriting the Node interface, but they also are quite distinct.

The attribute's effective value is determined as follows: if this attribute has been explicitly assigned any value, that value is the attribute's effective value; otherwise, if there is a declaration for this attribute, and that declaration includes a default value, then that default value is the attribute's effective value; otherwise, the attribute does not exist on this element in the structure model until it has been explicitly added. Note that the Node.nodeValue attribute on the Attr instance can also be used to retrieve the string version of the attribute's value(s).

If the attribute was not explicitly given a value in the instance document but has a default value provided by the schema associated with the document, an attribute node will be created with specified set to false. Removing attribute nodes for which a default value is defined in the schema generates a new attribute node with the default value and specified set to false. If validation occurred while invoking Document.normalizeDocument(), attribute nodes with specified equals to false are recomputed according to the default attribute values provided by the schema. If no default value is associate with this attribute in the schema, the attribute node is discarded.

In XML, where the value of an attribute can contain entity references, the child nodes of the Attr node may be either Text or EntityReference nodes (when these are in use; see the description of EntityReference for discussion).

The DOM Core represents all attribute values as simple strings, even if the DTD or schema associated with the document declares them of some specific type such as tokenized.

The way attribute value normalization is performed by the DOM implementation depends on how much the implementation knows about the schema in use. Typically, the value and nodeValue attributes of an Attr node initially returns the normalized value given by the parser. It is also the case after Document.normalizeDocument() is called (assuming the right options have been set). But this may not be the case after mutation, independently of whether the mutation is performed by setting the string value directly or by changing the Attr child nodes. In particular, this is true when character references are involved, given that they are not represented in the DOM and they impact attribute value normalization. On the other hand, if the implementation knows about the schema in use when the attribute value is changed, and it is of a different type than CDATA, it may normalize it again at that time. This is especially true of specialized DOM implementations, such as SVG DOM implementations, which storre attribute values in an internal form different from a string.

The following table gives some examples of the relations between the attribute value in the original document (parsed attribute), the value as exposed in the DOM, and the serialization of the value:

description

CDATA sections are used to escape blocks of text containing characters that would otherwise be regarded as markup. The only delimiter that is recognized in a CDATA section is the "]]>" string that ends the CDATA section. CDATA sections cannot be nested. Their primary purpose is for including material such as XML fragments, without needing to escape all the delimiters.

The CharacterData.data attribute holds the text that is contained by the CDATA section. Note that this may contain characters that need to be escaped outside of CDATA sections and that, depending on the character encoding ("charset") chosen for serialization, it may be impossible to write out some characters as part of a CDATA section.

The CDATASection interface inherits from the CharacterData interface through the Text interface. Adjacent CDATASection nodes are not merged by use of the normalize method of the Node interface.

No lexical check is done on the content of a CDATA section and it is therefore possible to have the character sequence "]]>" in the content, which is illegal in a CDATA section per section 2.7 of [XML 1.0]. The presence of this character sequence must generate a fatal error during serialization or the cdata section must be splitted before the serialization (see also the parameter "split-cdata-sections" in the DOMConfiguration interface).

One potential solution in the serialization process is to end the CDATA section before the character, output the character using a character reference or entity reference, and open a new CDATA section for any further characters in the text node. Note, however, that some code conversion libraries at the time of writing do not return an error or exception when a character is missing from the encoding, making the task of ensuring that data is not corrupted on serialization more difficult.

The CharacterData interface extends Node with a set of attributes and methods for accessing character data in the DOM. For clarity this set is defined here rather than on each object that uses these attributes and methods. No DOM objects correspond directly to CharacterData, though Text and others do inherit the interface from it. All offsets in this interface start from 0.

As explained in the DOMString interface, text strings in the DOM are represented in UTF-16, i.e. as a sequence of 16-bit units. In the following, the term 16-bit units is used whenever necessary to indicate that indexing on CharacterData is done in 16-bit units.

This interface inherits from CharacterData and represents the content of a comment, i.e., all the characters between the starting '<!--' and ending '-->'. Note that this is the definition of a comment in XML, and, in practice, HTML, although some HTML tools may implement the full SGML comment structure.

No lexical check is done on the content of a comment and it is therefore possible to have the character sequence "--" (double-hyphen) in the content, which is illegal in a comment per section 2.5 of [XML 1.0]. The presence of this character sequence must generate a fatal error during serialization.

The Counter interface is used to represent any counter or counters function value. This interface reflects the values in the underlying style property.

The CSS2Properties interface represents a convenience mechanism for retrieving and setting properties within a CSSStyleDeclaration. The attributes of this interface correspond to all the properties specified in CSS2. Getting an attribute of this interface is equivalent to calling the getPropertyValue method of the CSSStyleDeclaration interface. Setting an attribute of this interface is equivalent to calling the setProperty method of the CSSStyleDeclaration interface.

A conformant implementation of the CSS module is not required to implement the CSS2Properties interface. If an implementation does implement this interface, the expectation is that language-specific methods can be used to cast from an instance of the CSSStyleDeclaration interface to the CSS2Properties interface.

If an implementation does implement this interface, it is expected to understand the specific syntax of the shorthand properties, and apply their semantics; when the margin property is set, for example, the marginTop, marginRight, marginBottom and marginLeft properties are actually being set by the underlying implementation.

When dealing with CSS "shorthand" properties, the shorthand properties should be decomposed into their component longhand properties as appropriate, and when querying for their value, the form returned should be the shortest form exactly equivalent to the declarations made in the ruleset. However, if there is no shorthand declaration that could be added to the ruleset without changing in any way the rules already declared in the ruleset (i.e., by adding longhand rules that were previously not declared in the ruleset), then the empty string should be returned for the shorthand property.

For example, querying for the font property should not return "normal normal normal 14pt/normal Arial, sans-serif", when "14pt Arial, sans-serif" suffices. (The normals are initial values, and are implied by use of the longhand property.)

If the values for all the longhand properties that compose a particular string are the initial values, then a string consisting of all the initial values should be returned (e.g. a border-width value of "medium" should be returned as such, not as "").

For some shorthand properties that take missing values from other sides, such as the margin, padding, and border-[width|style|color] properties, the minimum number of sides possible should be used; i.e., "0px 10px" will be returned instead of "0px 10px 0px 10px".

If the value of a shorthand property can not be decomposed into its component longhand properties, as is the case for the font property with a value of "menu", querying for the values of the component longhand properties should return the empty string.

The CSSCharsetRule interface represents a @charset rule in a CSS style sheet. The value of the encoding attribute does not affect the encoding of text data in the DOM objects; this encoding is always UTF-16. After a stylesheet is loaded, the value of the encoding attribute is the value found in the @charset rule. If there was no @charset in the original document, then no CSSCharsetRule is created. The value of the encoding attribute may also be used as a hint for the encoding used on serialization of the style sheet.

The value of the @charset rule (and therefore of the CSSCharsetRule) may not correspond to the encoding the document actually came in; character encoding information e.g. in an HTTP header, has priority (see CSS document representation) but this is not reflected in the CSSCharsetRule.

The CSSStyleDeclaration interface represents a single CSS declaration block. This interface may be used to determine the style properties currently set in a block or to set style properties explicitly within the block.

While an implementation may not recognize all CSS properties within a CSS declaration block, it is expected to provide access to all specified properties in the style sheet through the CSSStyleDeclaration interface. Furthermore, implementations that support a specific level of CSS should correctly handle CSS shorthand properties for that level. For a further discussion of shorthand properties, see the CSS2Properties interface.

This interface is also used to provide a read-only access to the computed values of an element. See also the ViewCSS interface.

The CSSFontFaceRule interface represents a @font-face rule in a CSS style sheet. The @font-face rule is used to hold a set of font descriptions.

The CSSImportRule interface represents a @import rule within a CSS style sheet. The @import rule is used to import style rules from other style sheets.

The CSSMediaRule interface represents a @media rule in a CSS style sheet. A @media rule can be used to delimit style rules for specific media types.

The CSSPageRule interface represents a @page rule within a CSS style sheet. The @page rule is used to specify the dimensions, orientation, margins, etc. of a page box for paged media.

The CSSPrimitiveValue interface represents a single CSS value. This interface may be used to determine the value of a specific style property currently set in a block or to set a specific style property explicitly within the block. An instance of this interface might be obtained from the getPropertyCSSValue method of the CSSStyleDeclaration interface. A CSSPrimitiveValue object only occurs in a context of a CSS property.

Conversions are allowed between absolute values (from millimeters to centimeters, from degrees to radians, and so on) but not between relative values. (For example, a pixel value cannot be converted to a centimeter value.) Percentage values can't be converted since they are relative to the parent value (or another property value). There is one exception for color percentage values: since a color percentage value is relative to the range 0-255, a color percentage value can be converted to a number; (see also the RGBColor interface).

An integer indicating which type of unit applies to the value.

The CSSRule interface is the abstract base interface for any type of CSS statement. This includes both rule sets and at-rules. An implementation is expected to preserve all rules specified in a CSS style sheet, even if the rule is not recognized by the parser. Unrecognized rules are represented using the CSSUnknownRule interface.

An integer indicating which type of rule this is.

The CSSRuleList interface provides the abstraction of an ordered collection of CSS rules.

The items in the CSSRuleList are accessible via an integral index, starting from 0.

The CSSStyleRule interface represents a single rule set in a CSS style sheet.

The CSSStyleSheet interface is a concrete interface used to represent a CSS style sheet i.e., a style sheet whose content type is "text/css".

The CSSUnknownRule interface represents an at-rule not supported by this user agent.

The CSSValue interface represents a simple or a complex value. A CSSValue object only occurs in a context of a CSS property.

An integer indicating which type of unit applies to the value.

The CSSValueList interface provides the abstraction of an ordered collection of CSS values.

Some properties allow an empty list into their syntax. In that case, these properties take the none identifier. So, an empty list means that the property has the value none.

The items in the CSSValueList are accessible via an integral index, starting from 0.

The Document interface represents the entire HTML or XML document. Conceptually, it is the root of the document tree, and provides the primary access to the document's data.

Since elements, text nodes, comments, processing instructions, etc. cannot exist outside the context of a Document, the Document interface also contains the factory methods needed to create these objects. The Node objects created have a ownerDocument attribute which associates them with the Document within whose context they were created.

This interface represents a document with a CSS view.

The getOverrideStyle method provides a mechanism through which a DOM author could effect immediate change to the style of an element without modifying the explicitly linked style sheets of a document or the inline style of elements in the style sheets. This style sheet comes after the author style sheet in the cascade algorithm and is called override style sheet. The override style sheet takes precedence over author style sheets. An "!important" declaration still takes precedence over a normal declaration. Override, author, and user style sheets all may contain "!important" declarations. User "!important" rules take precedence over both override and author "!important" rules, and override "!important" rules take precedence over author "!important" rules.

The expectation is that an instance of the DocumentCSS interface can be obtained by using binding-specific casting methods on an instance of the Document interface.

DocumentFragment is a "lightweight" or "minimal" Document object. It is very common to want to be able to extract a portion of a document's tree or to create a new fragment of a document. Imagine implementing a user command like cut or rearranging a document by moving fragments around. It is desirable to have an object which can hold such fragments and it is quite natural to use a Node for this purpose. While it is true that a Document object could fulfill this role, a Document object can potentially be a heavyweight object, depending on the underlying implementation. What is really needed for this is a very lightweight object. DocumentFragment is such an object.

Furthermore, various operations -- such as inserting nodes as children of another Node -- may take DocumentFragment objects as arguments; this results in all the child nodes of the DocumentFragment being moved to the child list of this node.

The children of a DocumentFragment node are zero or more nodes representing the tops of any sub-trees defining the structure of the document. DocumentFragment nodes do not need to be well-formed XML documents (although they do need to follow the rules imposed upon well-formed XML parsed entities, which can have multiple top nodes). For example, a DocumentFragment might have only one child and that child node could be a Text node. Such a structure model represents neither an HTML document nor a well-formed XML document.

When a DocumentFragment is inserted into a Document (or indeed any other Node that may take children) the children of the DocumentFragment and not the DocumentFragment itself are inserted into the Node. This makes the DocumentFragment very useful when the user wishes to create nodes that are siblings; the DocumentFragment acts as the parent of these nodes so that the user can use the standard methods from the Node interface, such as Node.insertBefore and Node.appendChild.

The DocumentStyle interface provides a mechanism by which the style sheets embedded in a document can be retrieved. The expectation is that an instance of the DocumentStyle interface can be obtained by using binding-specific casting methods on an instance of the Document interface.

Each Document has a doctype attribute whose value is either null or a DocumentType object. The DocumentType interface in the DOM Core provides an interface to the list of entities that are defined for the document, and little else because the effect of namespaces and the various XML schema efforts on DTD representation are not clearly understood as of this writing.

DOM Level 3 doesn't support editing DocumentType nodes. DocumentType nodes are read-only.

The DOMConfiguration interface represents the configuration of a document and maintains a table of recognized parameters. Using the configuration, it is possible to change Document.normalizeDocument() behavior, such as replacing the CDATASection nodes with Text nodes or specifying the type of the schema that must be used when the validation of the Document is requested. DOMConfiguration objects are also used in [DOM Level 3 Load and Save] in the DOMParser and DOMSerializer interfaces.

The parameter names used by the DOMConfiguration object are defined throughout the DOM Level 3 specifications. Names are case-insensitive. To avoid possible conflicts, as a convention, names referring to parameters defined outside the DOM specification should be made unique. Because parameters are exposed as properties in the ECMAScript Language Binding, names are recommended to follow the section "5.16 Identifiers" of [Unicode] with the addition of the character '-' (HYPHEN-MINUS) but it is not enforced by the DOM implementation. DOM Level 3 Core Implementations are required to recognize all parameters defined in this specification. Some parameter values may also be required to be supported by the implementation. Refer to the definition of the parameter to know if a value must be supported or not.

The following list of parameters defined in the DOM:

The resolution of the system identifiers associated with entities is done using Document.documentURI. However, when the feature "LS" defined in [DOM Level 3 Load and Save] is supported by the DOM implementation, the parameter "resource-resolver" can also be used on DOMConfiguration objects attached to Document nodes. If this parameter is set, Document.normalizeDocument() will invoke the resource resolver instead of using Document.documentURI.

DOMError is an interface that describes an error.

An integer indicating the severity of the error.

DOMErrorHandler is a callback interface that the DOM implementation can call when reporting errors that happens while processing XML data, or when doing some other processing (e.g. validating a document). A DOMErrorHandler object can be attached to a Document using the "error-handler" on the DOMConfiguration interface. If more than one error needs to be reported during an operation, the sequence and numbers of the errors passed to the error handler are implementation dependent.

The application that is using the DOM implementation is expected to implement this interface.

DOM operations only raise exceptions in "exceptional" circumstances, i.e., when an operation is impossible to perform (either for logical reasons, because data is lost, or because the implementation has become unstable). In general, DOM methods return specific error values in ordinary processing situations, such as out-of-bound errors when using NodeList.

Implementations should raise other exceptions under other circumstances. For example, implementations should raise an implementation-dependent exception if a null argument is passed when null was not expected.

Some languages and object systems do not support the concept of exceptions. For such systems, error conditions may be indicated using native error reporting mechanisms. For some bindings, for example, methods may return error codes similar to those listed in the corresponding method descriptions.

The DOMImplementation interface provides a number of methods for performing operations that are independent of any particular instance of the document object model.

This interface allows the DOM user to create a CSSStyleSheet outside the context of a document. There is no way to associate the new CSSStyleSheet with a document in DOM Level 2.

The DOMImplementationList interface provides the abstraction of an ordered collection of DOM implementations, without defining or constraining how this collection is implemented. The items in the DOMImplementationList are accessible via an integral index, starting from 0.

This interface permits a DOM implementer to supply one or more implementations, based upon requested features and versions, as specified in DOM Features. Each implemented DOMImplementationSource object is listed in the binding-specific list of available sources so that its DOMImplementation objects are made available.

DOMLocator is an interface that describes a location (e.g. where an error occurred).

A DOMObject represents an object reference.

For Java and ECMAScript, DOMObject is bound to the Object type.

The DOMString type is used to store [Unicode] characters as a sequence of 16-bit units using UTF-16 as defined in [Unicode] and Amendment 1 of [ISO/IEC 10646].

Characters are fully normalized as defined in appendix B of [XML 1.1] if:

Note that, with the exceptions of Document.normalizeDocument() and Node.normalize(), manipulating characters using DOM methods does not guarantee to preserve a fully-normalized text.

A DOMString is a sequence of 16-bit units.

The UTF-16 encoding was chosen because of its widespread industry practice. Note that for both HTML and XML, the document character set (and therefore the notation of numeric character references) is based on UCS [ISO/IEC 10646]. A single numeric character reference in a source document may therefore in some cases correspond to two 16-bit units in a DOMString (a high surrogate and a low surrogate). For issues related to string comparisons, refer to String Comparisons in the DOM.

For Java and ECMAScript, DOMString is bound to the String type because both languages also use UTF-16 as their encoding.

The DOMTimeStamp type is used to store an absolute or relative time.

A DOMTimeStamp represents a number of milliseconds.

For Java, DOMTimeStamp is bound to the long type. For ECMAScript, DOMTimeStamp is bound to the Date type because the range of the integer type is too small.

A DOMUserData represents a reference to application data.

For Java, DOMUserData is bound to the Object type. For ECMAScript, DOMUserData is bound to any type.

The Element interface represents an element in an HTML or XML document. Elements may have attributes associated with them; since the Element interface inherits from Node, the generic Node interface attribute attributes may be used to retrieve the set of all attributes for an element. There are methods on the Element interface to retrieve either an Attr object by name or an attribute value by name. In XML, where an attribute value may contain entity references, an Attr object should be retrieved to examine the possibly fairly complex sub-tree representing the attribute value. On the other hand, in HTML, where all attributes have simple string values, methods to directly access an attribute value can safely be used as a convenience.

Inline style information attached to elements is exposed through the style attribute. This represents the contents of the STYLE attribute for HTML elements (or elements in other schemas or DTDs which use the STYLE attribute in the same way). The expectation is that an instance of the ElementCSSInlineStyle interface can be obtained by using binding-specific casting methods on an instance of the Element interface when the element supports inline CSS style informations.

This interface represents a known entity, either parsed or unparsed, in an XML document. Note that this models the entity itself not the entity declaration.

The nodeName attribute that is inherited from Node contains the name of the entity.

An XML processor may choose to completely expand entities before the structure model is passed to the DOM; in this case there will be no EntityReference nodes in the document tree.

XML does not mandate that a non-validating XML processor read and process entity declarations made in the external subset or declared in parameter entities. This means that parsed entities declared in the external subset need not be expanded by some classes of applications, and that the replacement text of the entity may not be available. When the replacement text is available, the corresponding Entity node's child list represents the structure of that replacement value. Otherwise, the child list is empty.

DOM Level 3 does not support editing Entity nodes; if a user wants to make changes to the contents of an Entity, every related EntityReference node has to be replaced in the structure model by a clone of the Entity's contents, and then the desired changes must be made to each of those clones instead. Entity nodes and all their descendants are readonly.

An Entity node does not have any parent.

EntityReference nodes may be used to represent an entity reference in the tree. Note that character references and references to predefined entities are considered to be expanded by the HTML or XML processor so that characters are represented by their Unicode equivalent rather than by an entity reference. Moreover, the XML processor may completely expand references to entities while building the Document, instead of providing EntityReference nodes. If it does provide such nodes, then for an EntityReference node that represents a reference to a known entity an Entity exists, and the subtree of the EntityReference node is a copy of the Entity node subtree. However, the latter may not be true when an entity contains an unbound namespace prefix. In such a case, because the namespace prefix resolution depends on where the entity reference is, the descendants of the EntityReference node may be bound to different namespace URIs. When an EntityReference node represents a reference to an unknown entity, the node has no children and its replacement value, when used by Attr.value for example, is empty.

As for Entity nodes, EntityReference nodes and all their descendants are readonly.

The anchor element. See the A element definition in HTML 4.01.

Client-side image map area definition. See the AREA element definition in HTML 4.01.

Document base URI [IETF RFC 2396]. See the BASE element definition in HTML 4.01.

Base font. See the BASEFONT element definition in HTML 4.01. This element is deprecated in HTML 4.01.

The HTML document body. This element is always present in the DOM API, even if the tags are not present in the source document. See the BODY element definition in HTML 4.01.

Force a line break. See the BR element definition in HTML 4.01.

Push button. See the BUTTON element definition in HTML 4.01.

An HTMLCollection is a list of nodes. An individual node may be accessed by either ordinal index or the node's name or id attributes.

Directory list. See the DIR element definition in HTML 4.01. This element is deprecated in HTML 4.01.

Generic block container. See the DIV element definition in HTML 4.01.

Definition list. See the DL element definition in HTML 4.01.

An HTMLDocument is the root of the HTML hierarchy and holds the entire content. Besides providing access to the hierarchy, it also provides some convenience methods for accessing certain sets of information from the document.

The following properties have been deprecated in favor of the corresponding ones for the BODY element:

Organizes form controls into logical groups. See the FIELDSET element definition in HTML 4.01.

Local change to font. See the FONT element definition in HTML 4.01. This element is deprecated in HTML 4.01.

The FORM element encompasses behavior similar to a collection and an element. It provides direct access to the contained form controls as well as the attributes of the form element. See the FORM element definition in HTML 4.01.

Create a frame. See the FRAME element definition in HTML 4.01.

Create a grid of frames. See the FRAMESET element definition in HTML 4.01.

All HTML element interfaces derive from this class. Elements that only expose the HTML core attributes are represented by the base HTMLElement interface. These elements are as follows:

Document head information. See the HEAD element definition in HTML 4.01.

For the H1 to H6 elements. See the H1 element definition in HTML 4.01.

Create a horizontal rule. See the HR element definition in HTML 4.01.

Inline subwindows. See the IFRAME element definition in HTML 4.01.

Embedded image. See the IMG element definition in HTML 4.01.

Form control.

This element is used for single-line text input. See the ISINDEX element definition in HTML 4.01. This element is deprecated in HTML 4.01.

Form field label text. See the LABEL element definition in HTML 4.01.

Provides a caption for a FIELDSET grouping. See the LEGEND element definition in HTML 4.01.

List item. See the LI element definition in HTML 4.01.

The LINK element specifies a link to an external resource, and defines this document's relationship to that resource (or vice versa). See the LINK element definition in HTML 4.01 (see also the LinkStyle interface in the StyleSheet module [DOM Level 2 Style Sheets and CSS]).

Client-side image map. See the MAP element definition in HTML 4.01.

Menu list. See the MENU element definition in HTML 4.01. This element is deprecated in HTML 4.01.

This contains generic meta-information about the document. See the META element definition in HTML 4.01.

Notice of modification to part of a document. See the INS and DEL element definitions in HTML 4.01.

Generic embedded object.

Ordered list. See the OL element definition in HTML 4.01.

Group options together in logical subdivisions. See the OPTGROUP element definition in HTML 4.01.

A selectable choice. See the OPTION element definition in HTML 4.01.

An HTMLOptionsCollection is a list of nodes representing HTML option element. An individual node may be accessed by either ordinal index or the node's name or id attributes.

Paragraphs. See the P element definition in HTML 4.01.

Parameters fed to the OBJECT element. See the PARAM element definition in HTML 4.01.

Preformatted text. See the PRE element definition in HTML 4.01.

For the Q and BLOCKQUOTE elements. See the Q element definition in HTML 4.01.

Script statements. See the SCRIPT element definition in HTML 4.01.

The select element allows the selection of an option. The contained options can be directly accessed through the select element as a collection. See the SELECT element definition in HTML 4.01.

Style information. See the STYLE element definition in HTML 4.01, the CSS module [DOM Level 2 Style Sheets and CSS] and the LinkStyle interface in the StyleSheets module [DOM Level 2 Style Sheets and CSS].

The object used to represent the TH and TD elements. See the TD element definition in HTML 4.01.

Table caption See the CAPTION element definition in HTML 4.01.

Regroups the COL and COLGROUP elements. See the COL element definition in HTML 4.01.

The create* and delete* methods on the table allow authors to construct and modify tables. [HTML 4.01] specifies that only one of each of the CAPTION, THEAD, and TFOOT elements may exist in a table. Therefore, if one exists, and the createTHead() or createTFoot() method is called, the method returns the existing THead or TFoot element. See the TABLE element definition in HTML 4.01.

A row in a table. See the TR element definition in HTML 4.01.

The THEAD, TFOOT, and TBODY elements.

Multi-line text field. See the TEXTAREA element definition in HTML 4.01.

The document title. See the TITLE element definition in HTML 4.01.

Unordered list. See the UL element definition in HTML 4.01.

The LinkStyle interface provides a mechanism by which a style sheet can be retrieved from the node responsible for linking it into a document. An instance of the LinkStyle interface can be obtained using binding-specific casting methods on an instance of a linking node (HTMLLinkElement, HTMLStyleElement or ProcessingInstruction in DOM Level 2).

The MediaList interface provides the abstraction of an ordered collection of media, without defining or constraining how this collection is implemented. An empty list is the same as a list that contains the medium "all".

The items in the MediaList are accessible via an integral index, starting from 0.

Objects implementing the NamedNodeMap interface are used to represent collections of nodes that can be accessed by name. Note that NamedNodeMap does not inherit from NodeList; NamedNodeMaps are not maintained in any particular order. Objects contained in an object implementing NamedNodeMap may also be accessed by an ordinal index, but this is simply to allow convenient enumeration of the contents of a NamedNodeMap, and does not imply that the DOM specifies an order to these Nodes.

NamedNodeMap objects in the DOM are live.

The NameList interface provides the abstraction of an ordered collection of parallel pairs of name and namespace values (which could be null values), without defining or constraining how this collection is implemented. The items in the NameList are accessible via an integral index, starting from 0.

The Node interface is the primary datatype for the entire Document Object Model. It represents a single node in the document tree. While all objects implementing the Node interface expose methods for dealing with children, not all objects implementing the Node interface may have children. For example, Text nodes may not have children, and adding children to such nodes results in a DOMException being raised.

The attributes nodeName, nodeValue and attributes are included as a mechanism to get at node information without casting down to the specific derived interface. In cases where there is no obvious mapping of these attributes for a specific nodeType (e.g., nodeValue for an Element or attributes for a Comment), this returns null. Note that the specialized interfaces may contain additional and more convenient mechanisms to get and set the relevant information.

An integer indicating which type of node this is.

The values of nodeName, nodeValue, and attributes vary according to the node type as follows:

A bitmask indicating the relative document position of a node with respect to another node.

If the two nodes being compared are the same node, then no flags are set on the return.

Otherwise, the order of two nodes is determined by looking for common containers -- containers which contain both. A node directly contains any child nodes. A node also directly contains any other nodes attached to it such as attributes contained in an element or entities and notations contained in a document type. Nodes contained in contained nodes are also contained, but less-directly as the number of intervening containers increases.

If there is no common container node, then the order is based upon order between the root container of each node that is in no container. In this case, the result is disconnected and implementation-specific. This result is stable as long as these outer-most containing nodes remain in memory and are not inserted into some other containing node. This would be the case when the nodes belong to different documents or fragments, and cloning the document or inserting a fragment might change the order.

If one of the nodes being compared contains the other node, then the container precedes the contained node, and reversely the contained node follows the container. For example, when comparing an element against its own attribute or child, the element node precedes its attribute node and its child node, which both follow it.

If neither of the previous cases apply, then there exists a most-direct container common to both nodes being compared. In this case, the order is determined based upon the two determining nodes directly contained in this most-direct common container that either are or contain the corresponding nodes being compared.

If these two determining nodes are both child nodes, then the natural DOM order of these determining nodes within the containing node is returned as the order of the corresponding nodes. This would be the case, for example, when comparing two child elements of the same element.

If one of the two determining nodes is a child node and the other is not, then the corresponding node of the child node follows the corresponding node of the non-child node. This would be the case, for example, when comparing an attribute of an element with a child element of the same element.

If neither of the two determining node is a child node and one determining node has a greater value of nodeType than the other, then the corresponding node precedes the other. This would be the case, for example, when comparing an entity of a document type against a notation of the same document type.

If neither of the two determining node is a child node and nodeType is the same for both determining nodes, then an implementation-dependent order between the determining nodes is returned. This order is stable as long as no nodes of the same nodeType are inserted into or removed from the direct container. This would be the case, for example, when comparing two attributes of the same element, and inserting or removing additional attributes might change the order between existing attributes.