REC-DOM-Level-1-19981001 Document Object Model (DOM) Level 1 Specification Version 1.0 W3C Recommendation 1 October, 1998 This version http://www.w3.org/TR/1998/REC-DOM-Level-1-19981001 http://www.w3.org/TR/1998/REC-DOM-Level-1-19981001/DOM.ps http://www.w3.org/TR/1998/REC-DOM-Level-1-19981001/DOM.pdf http://www.w3.org/TR/1998/REC-DOM-Level-1-19981001/DOM.tgz http://www.w3.org/TR/1998/REC-DOM-Level-1-19981001/DOM.zip http://www.w3.org/TR/1998/REC-DOM-Level-1-19981001/DOM.txt Latest version http://www.w3.org/TR/REC-DOM-Level-1 Previous versions http://www.w3.org/TR/1998/PR-DOM-Level-1-19980818 http://www.w3.org/TR/1998/WD-DOM-19980720 http://www.w3.org/TR/1998/WD-DOM-19980416 http://www.w3.org/TR/WD-DOM-19980318 http://www.w3.org/TR/WD-DOM-971209 http://www.w3.org/TR/WD-DOM-971009 WG Chair Lauren Wood, SoftQuad, Inc. Editors Vidur Apparao, Netscape Steve Byrne, Sun Mike Champion, ArborText Scott Isaacs, Microsoft Ian Jacobs, W3C Arnaud Le Hors, W3C Gavin Nicol, Inso EPS Jonathan Robie, Texcel Research Robert Sutor, IBM Chris Wilson, Microsoft Lauren Wood, SoftQuad, Inc. Principal Contributors Vidur Apparao, Netscape Steve Byrne, Sun (until November 1997) Mike Champion, ArborText, Inc. Scott Isaacs, Microsoft (until January, 1998) Arnaud Le Hors, W3C Gavin Nicol, Inso EPS Jonathan Robie, Texcel Research Peter Sharpe, SoftQuad, Inc. Bill Smith, Sun (after November 1997) Jared Sorensen, Novell Robert Sutor, IBM Ray Whitmer, iMall Chris Wilson, Microsoft (after January, 1998) Status of this document This document has been reviewed by W3C Members and other interested parties and has been endorsed by the Director as a W3C Recommendation. It is a stable document and may be used as reference material or cited as a normative reference from another document. W3C's role in making the Recommendation is to draw attention to the specification and to promote its widespread deployment. This enhances the functionality and interoperability of the Web. The authors of this document are the DOM Working Group members, different chapters may have different editors. Comments on this document should be sent to the public mailing list www-dom@w3.org. A list of current W3C Recommendations and other technical documents can be found at http://www.w3.org/TR. Errata The list of known errors in this document is found at http://www.w3.org/DOM/updates/REC-DOM-Level-1-19981001-errata.html. Available Languages The English version of this specification is the only normative version. However, for translations in other languages see http://www.w3.org/DOM/updates/REC-DOM-Level-1-translations.html. Abstract This specification defines the Document Object Model Level 1, a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content, structure and style of documents. The Document Object Model provides a standard set of objects for representing HTML and XML documents, a standard model of how these objects can be combined, and a standard interface for accessing and manipulating them. Vendors can support the DOM as an interface to their proprietary data structures and APIs, and content authors can write to the standard DOM interfaces rather than product-specific APIs, thus increasing interoperability on the Web. The goal of the DOM specification is to define a programmatic interface for XML and HTML. The DOM Level 1 specification is separated into two parts: Core and HTML. The Core DOM Level 1 section provides a low-level set of fundamental interfaces that can represent any structured document, as well as defining extended interfaces for representing an XML document. These extended XML interfaces need not be implemented by a DOM implementation that only provides access to HTML documents; all of the fundamental interfaces in the Core section must be implemented. A compliant DOM implementation that implements the extended XML interfaces is required to also implement the fundamental Core interfaces, but not the HTML interfaces. The HTML Level 1 section provides additional, higher-level interfaces that are used with the fundamental interfaces defined in the Core Level 1 section to provide a more convenient view of an HTML document. A compliant implementation of the HTML DOM implements all of the fundamental Core interfaces as well as the HTML interfaces. Table of contents * Expanded Table of Contents * Copyright Notice * What is the Document Object Model? * Chapter 1: Document Object Model (Core) Level 1 * Chapter 2: Document Object Model (HTML) Level 1 * Appendix A: Contributors * Appendix B: Glossary * Appendix C: IDL Definitions * Appendix D: Java Language Binding * Appendix E: ECMA Script Language Binding * References * Index * Production Notes (Non-Normative) Expanded Table of Contents * Expanded Table of Contents * Copyright Notice * What is the Document Object Model? o Introduction o What the Document Object Model is o What the Document Object Model is not o Where the Document Object Model came from o Entities and the DOM Core o DOM Interfaces and DOM Implementations o Limitations of Level 1 * Chapter 1: Document Object Model (Core) Level 1 o 1.1. Overview of the DOM Core Interfaces + 1.1.1. The DOM Structure Model + 1.1.2. Memory Management + 1.1.3. Naming Conventions + 1.1.4. Inheritance vs Flattened Views of the API + 1.1.5. The DOMString type + 1.1.6. Case sensitivity in the DOM o 1.2. Fundamental Interfaces o 1.3. Extended Interfaces * Chapter 2: Document Object Model (HTML) Level 1 o 2.1. Introduction o 2.2. HTML Application of Core DOM + 2.2.1. Naming Conventions o 2.3. Miscellaneous Object Definitions o 2.4. Objects related to HTML documents o 2.5. HTML Elements + 2.5.1. Property Attributes + 2.5.2. Naming Exceptions + 2.5.3. Exposing Element Type Names (tagName) + 2.5.4. The HTMLElement interface + 2.5.5. Object definitions * Appendix A: Contributors * Appendix B: Glossary * Appendix C: IDL Definitions o C.1. Document Object Model Level 1 Core o C.2. Document Object Model Level 1 HTML * Appendix D: Java Language Binding o D.1. Document Object Model Level 1 Core o D.2. Document Object Model Level 1 HTML * Appendix E: ECMA Script Language Binding o E.1. Document Object Model Level 1 Core o E.2. Document Object Model Level 1 HTML * References * Index * Production Notes (Non-Normative) o 1. The Document Type Definition o 2. The production process o 3. Object Definitions Copyright Notice Copyright © 1998 World Wide Web Consortium , (Massachusetts Institute of Technology , Institut National de Recherche en Informatique et en Automatique , Keio University ). All Rights Reserved. Documents on the W3C site are provided by the copyright holders under the following license. By obtaining, using and/or copying this document, or the W3C document from which this statement is linked, you agree that you have read, understood, and will comply with the following terms and conditions: Permission to use, copy, and distribute the contents of this document, or the W3C document from which this statement is linked, in any medium for any purpose and without fee or royalty is hereby granted, provided that you include the following on ALL copies of the document, or portions thereof, that you use: 1. A link or URI to the original W3C document. 2. The pre-existing copyright notice of the original author, if it doesn't exist, a notice of the form: "Copyright © World Wide Web Consortium , (Massachusetts Institute of Technology , Institut National de Recherche en Informatique et en Automatique , Keio University ). All Rights Reserved." 3. If it exists, the STATUS of the W3C document. When space permits, inclusion of the full text of this NOTICE should be provided. In addition, credit shall be attributed to the copyright holders for any software, documents, or other items or products that you create pursuant to the implementation of the contents of this document, or any portion thereof. No right to create modifications or derivatives is granted pursuant to this license. THIS DOCUMENT IS PROVIDED "AS IS," AND COPYRIGHT HOLDERS MAKE NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, OR TITLE; THAT THE CONTENTS OF THE DOCUMENT ARE SUITABLE FOR ANY PURPOSE; NOR THAT THE IMPLEMENTATION OF SUCH CONTENTS WILL NOT INFRINGE ANY THIRD PARTY PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS. COPYRIGHT HOLDERS WILL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF ANY USE OF THE DOCUMENT OR THE PERFORMANCE OR IMPLEMENTATION OF THE CONTENTS THEREOF. The name and trademarks of copyright holders may NOT be used in advertising or publicity pertaining to this document or its contents without specific, written prior permission. Title to copyright in this document will at all times remain with copyright holders. What is the Document Object Model? Editors Jonathan Robie, Texcel Research Introduction The Document Object Model (DOM) is an application programming interface (API) for HTML and XML documents. It defines the logical structure of documents and the way a document is accessed and manipulated. In the DOM specification, the term "document" is used in the broad sense - increasingly, XML is being used as a way of representing many different kinds of information that may be stored in diverse systems, and much of this would traditionally be seen as data rather than as documents. Nevertheless, XML presents this data as documents, and the DOM may be used to manage this data. With the Document Object Model, programmers can build documents, navigate their structure, and add, modify, or delete elements and content. Anything found in an HTML or XML document can be accessed, changed, deleted, or added using the Document Object Model, with a few exceptions - in particular, the DOM interfaces for the XML internal and external subsets have not yet been specified. As a W3C specification, one important objective for the Document Object Model is to provide a standard programming interface that can be used in a wide variety of environments and applications. The DOM is designed to be used with any programming language. In order to provide a precise, language-independent specification of the DOM interfaces, we have chosen to define the specifications in OMG IDL, as defined in the CORBA 2.2 specification. In addition to the OMG IDL specification, we provide language bindings for Java and ECMAScript (an industry-standard scripting language based on JavaScript and JScript). Note: OMG IDL is used only as a language-independent and implementation-neutral way to specify interfaces. Various other IDLs could have been used. In general, IDLs are designed for specific computing environments. The Document Object Model can be implemented in any computing environment, and does not require the object binding runtimes generally associated with such IDLs. What the Document Object Model is The DOM is a programming API for documents. It closely resembles the structure of the documents it models. For instance, consider this table, taken from an HTML document:
Shady Grove Aeolian
Over the River, Charlie Dorian
The DOM represents this table like this: --------------------------------------------------------------------- [DOM representation of the example table] --------------------------------------------------------------------- DOM representation of the example table --------------------------------------------------------------------- In the DOM, documents have a logical structure which is very much like a tree; to be more precise, it is like a "forest" or "grove", which can contain more than one tree. However, the DOM does not specify that documents must be implemented as a tree or a grove, nor does it specify how the relationships among objects be implemented. The DOM is a logical model that may be implemented in any convenient manner. In this specification, we use the term structure model to describe the tree-like representation of a document; we specifically avoid terms like "tree" or "grove" in order to avoid implying a particular implementation. One important property of DOM structure models is structural isomorphism: if any two Document Object Model implementations are used to create a representation of the same document, they will create the same structure model, with precisely the same objects and relationships. The name "Document Object Model" was chosen because it is an "object model" in the traditional object oriented design sense: documents are modeled using objects, and the model encompasses not only the structure of a document, but also the behavior of a document and the objects of which it is composed. In other words, the nodes in the above diagram do not represent a data structure, they represent objects, which have functions and identity. As an object model, the DOM identifies: * the interfaces and objects used to represent and manipulate a document * the semantics of these interfaces and objects - including both behavior and attributes * the relationships and collaborations among these interfaces and objects The structure of SGML documents has traditionally been represented by an abstract data model, not by an object model. In an abstract data model, the model is centered around the data. In object oriented programming languages, the data itself is encapsulated in objects that hide the data, protecting it from direct external manipulation. The functions associated with these objects determine how the objects may be manipulated, and they are part of the object model. The Document Object Model currently consists of two parts, DOM Core and DOM HTML. The DOM Core represents the functionality used for XML documents, and also serves as the basis for DOM HTML. A compliant implementation of the DOM must implement all of the fundamental interfaces in the Core chapter with the semantics as defined. Further, it must implement at least one of the HTML DOM and the extended (XML) interfaces with the semantics as defined. What the Document Object Model is not This section is designed to give a more precise understanding of the DOM by distinguishing it from other systems that may seem to be like it. * Although the Document Object Model was strongly influenced by "Dynamic HTML", in Level 1, it does not implement all of "Dynamic HTML". In particular, events have not yet been defined. Level 1 is designed to lay a firm foundation for this kind of functionality by providing a robust, flexible model of the document itself. * The Document Object Model is not a binary specification. DOM programs written in the same language will be source code compatible across platforms, but the DOM does not define any form of binary interoperability. * The Document Object Model is not a way of persisting objects to XML or HTML. Instead of specifying how objects may be represented in XML, the DOM specifies how XML and HTML documents are represented as objects, so that they may be used in object oriented programs. * The Document Object Model is not a set of data structures, it is an object model that specifies interfaces. Although this document contains diagrams showing parent/child relationships, these are logical relationships defined by the programming interfaces, not representations of any particular internal data structures. * The Document Object Model does not define "the true inner semantics" of XML or HTML. The semantics of those languages are defined by W3C Recommendations for these languages. The DOM is a programming model designed to respect these semantics. The DOM does not have any ramifications for the way you write XML and HTML documents; any document that can be written in these languages can be represented in the DOM. * The Document Object Model, despite its name, is not a competitor to the Component Object Model (COM). COM, like CORBA, is a language independent way to specify interfaces and objects; the DOM is a set of interfaces and objects designed for managing HTML and XML documents. The DOM may be implemented using language-independent systems like COM or CORBA; it may also be implemented using language-specific bindings like the Java or ECMAScript bindings specified in this document. Where the Document Object Model came from The DOM originated as a specification to allow JavaScript scripts and Java programs to be portable among Web browsers. "Dynamic HTML" was the immediate ancestor of the Document Object Model, and it was originally thought of largely in terms of browsers. However, when the DOM Working Group was formed at W3C, it was also joined by vendors in other domains, including HTML or XML editors and document repositories. Several of these vendors had worked with SGML before XML was developed; as a result, the DOM has been influenced by SGML Groves and the HyTime standard. Some of these vendors had also developed their own object models for documents in order to provide an API for SGML/XML editors or document repositories, and these object models have also influenced the DOM. Entities and the DOM Core In the fundamental DOM interfaces, there are no objects representing entities. Numeric character references, and references to the pre-defined entities in HTML and XML, are replaced by the single character that makes up the entity's replacement. For example, in:

This is a dog & a cat

the "&" will be replaced by the character "&", and the text in the P element will form a single continuous sequence of characters. Since numeric character references and pre-defined entities are not recognized as such in CDATA sections, or the SCRIPT and STYLE elements in HTML, they are not replaced by the single character they appear to refer to. If the example above were enclosed in a CDATA section, the "&" would not be replaced by "&"; neither would the

be recognized as a start tag. The representation of general entities, both internal and external, are defined within the extended (XML) interfaces of the Level 1 specification. Note: When a DOM representation of a document is serialized as XML or HTML text, applications will need to check each character in text data to see if it needs to be escaped using a numeric or pre-defined entity. Failing to do so could result in invalid HTML or XML. Also, implementations should be aware of the fact that serialization into a character encoding ("charset") that does not fully cover ISO 10646 may fail if there are characters in markup or CDATA sections that are not present in the encoding. DOM Interfaces and DOM Implementations The DOM specifies interfaces which may be used to manage XML or HTML documents. It is important to realize that these interfaces are an abstraction - much like "abstract base classes" in C++, they are a means of specifying a way to access and manipulate an application's internal representation of a document. Interfaces do not imply a particular concrete implementation. Each DOM application is free to maintain documents in any convenient representation, as long as the interfaces shown in this specification are supported. Some DOM implementations will be existing programs that use the DOM interfaces to access software written long before the DOM specification existed. Therefore, the DOM is designed to avoid implementation dependencies; in particular, 1. Attributes defined in the IDL do not imply concrete objects which must have specific data members - in the language bindings, they are translated to a pair of get()/set() functions, not to a data member. (Read-only functions have only a get() function in the language bindings). 2. DOM applications may provide additional interfaces and objects not found in this specification and still be considered DOM compliant. 3. Because we specify interfaces and not the actual objects that are to be created, the DOM can not know what constructors to call for an implementation. In general, DOM users call the createXXX() methods on the Document class to create document structures, and DOM implementations create their own internal representations of these structures in their implementations of the createXXX() functions. Limitations of Level 1 The DOM Level 1 specification is intentionally limited to those methods needed to represent and manipulate document structure and content. The plan is for future Levels of the DOM specification to provide: 1. A structure model for the internal subset and the external subset. 2. Validation against a schema. 3. Control for rendering documents via style sheets. 4. Access control. 5. Thread-safety. 6. Events. 1. Document Object Model (Core) Level 1 Editors Mike Champion, ArborText (from November 20, 1997) Steve Byrne, JavaSoft (until November 19, 1997) Gavin Nicol, Inso EPS Lauren Wood, SoftQuad, Inc. 1.1. Overview of the DOM Core Interfaces This section defines a minimal set of objects and interfaces for accessing and manipulating document objects. The functionality specified in this section (the Core functionality) should be sufficient to allow software developers and web script authors to access and manipulate parsed HTML and XML content inside conforming products. The DOM Core API also allows population of a Document object using only DOM API calls; creating the skeleton Document and saving it persistently is left to the product that implements the DOM API. 1.1.1. The DOM Structure Model The DOM presents documents as a hierarchy of Node objects that also implement other, more specialized interfaces. Some types of nodes may have child nodes of various types, and others are leaf nodes that cannot have anything below them in the document structure. The node types, and which node types they may have as children, are as follows: * Document -- Element (maximum of one), ProcessingInstruction, Comment, DocumentType * DocumentFragment -- Element, ProcessingInstruction, Comment, Text, CDATASection, EntityReference * DocumentType -- no children * EntityReference -- Element, ProcessingInstruction, Comment, Text, CDATASection, EntityReference * Element -- Element, Text, Comment, ProcessingInstruction, CDATASection, EntityReference * Attr -- Text, EntityReference * ProcessingInstruction -- no children * Comment -- no children * Text -- no children * CDATASection -- no children * Entity -- Element, ProcessingInstruction, Comment, Text, CDATASection, EntityReference * Notation -- no children The DOM also specifies a NodeList interface to handle ordered lists of Nodes, such as the children of a Node, or the elements returned by the Element.getElementsByTagName method, and also a NamedNodeMap interface to handle unordered sets of nodes referenced by their name attribute, such as the attributes of an Element. NodeLists and NamedNodeMaps in the DOM are "live", that is, changes to the underlying document structure are reflected in all relevant NodeLists and NamedNodeMaps. For example, if a DOM user gets a NodeList object containing the children of an Element, then subsequently adds more children to that element (or removes children, or modifies them), those changes are automatically reflected in the NodeList without further action on the user's part. Likewise changes to a Node in the tree are reflected in all references to that Node in NodeLists and NamedNodeMaps. 1.1.2. Memory Management Most of the APIs defined by this specification are interfaces rather than classes. That means that an actual implementation need only expose methods with the defined names and specified operation, not actually implement classes that correspond directly to the interfaces. This allows the DOM APIs to be implemented as a thin veneer on top of legacy applications with their own data structures, or on top of newer applications with different class hierarchies. This also means that ordinary constructors (in the Java or C++ sense) cannot be used to create DOM objects, since the underlying objects to be constructed may have little relationship to the DOM interfaces. The conventional solution to this in object-oriented design is to define factory methods that create instances of objects that implement the various interfaces. In the DOM Level 1, objects implementing some interface "X" are created by a "createX()" method on the Document interface; this is because all DOM objects live in the context of a specific Document. The DOM Level 1 API does not define a standard way to create DOMImplementation or Document objects; actual DOM implementations must provide some proprietary way of bootstrapping these DOM interfaces, and then all other objects can be built from the Create methods on Document (or by various other convenience methods). The Core DOM APIs are designed to be compatible with a wide range of languages, including both general-user scripting languages and the more challenging languages used mostly by professional programmers. Thus, the DOM APIs need to operate across a variety of memory management philosophies, from language platforms that do not expose memory management to the user at all, through those (notably Java) that provide explicit constructors but provide an automatic garbage collection mechanism to automatically reclaim unused memory, to those (especially C/C++) that generally require the programmer to explicitly allocate object memory, track where it is used, and explicitly free it for re-use. To ensure a consistent API across these platforms, the DOM does not address memory management issues at all, but instead leaves these for the implementation. Neither of the explicit language bindings devised by the DOM Working Group (for ECMAScript and Java) require any memory management methods, but DOM bindings for other languages (especially C or C++) probably will require such support. These extensions will be the responsibility of those adapting the DOM API to a specific language, not the DOM WG. 1.1.3. Naming Conventions While it would be nice to have attribute and method names that are short, informative, internally consistent, and familiar to users of similar APIs, the names also should not clash with the names in legacy APIs supported by DOM implementations. Furthermore, both OMG IDL and ECMAScript have significant limitations in their ability to disambiguate names from different namespaces that makes it difficult to avoid naming conflicts with short, familiar names. So, DOM names tend to be long and quite descriptive in order to be unique across all environments. The Working Group has also attempted to be internally consistent in its use of various terms, even though these may not be common distinctions in other APIs. For example, we use the method name "remove" when the method changes the structural model, and the method name "delete" when the method gets rid of something inside the structure model. The thing that is deleted is not returned. The thing that is removed may be returned, when it makes sense to return it. 1.1.4. Inheritance vs Flattened Views of the API The DOM Core APIs present two somewhat different sets of interfaces to an XML/HTML document; one presenting an "object oriented" approach with a hierarchy of inheritance, and a "simplified" view that allows all manipulation to be done via the Node interface without requiring casts (in Java and other C-like languages) or query interface calls in COM environments. These operations are fairly expensive in Java and COM, and the DOM may be used in performance-critical environments, so we allow significant functionality using just the Node interface. Because many other users will find the inheritance hierarchy easier to understand than the "everything is a Node" approach to the DOM, we also support the full higher-level interfaces for those who prefer a more object-oriented API. In practice, this means that there is a certain amount of redundancy in the API. The Working Group considers the "inheritance" approach the primary view of the API, and the full set of functionality on Node to be "extra" functionality that users may employ, but that does not eliminate the need for methods on other interfaces that an object-oriented analysis would dictate. (Of course, when the O-O analysis yields an attribute or method that is identical to one on the Node interface, we don't specify a completely redundant one). Thus, even though there is a generic nodeName attribute on the Node interface, there is still a tagName attribute on the Element interface; these two attributes must contain the same value, but the Working Group considers it worthwhile to support both, given the different constituencies the DOM API must satisfy. 1.1.5. The DOMString type To ensure interoperability, the DOM specifies the DOMString type as follows: * A DOMString is a sequence of 16-bit quantities. This may be expressed in IDL terms as: typedef sequence DOMString; * Applications must encode DOMString using UTF-16 (defined in Appendix C.3 of [UNICODE] and Amendment 1 of [ISO-10646]).The UTF-16 encoding was chosen because of its widespread industry practice. Please note that for both HTML and XML, the document character set (and therefore the notation of numeric character references) is based on UCS-4. A single numeric character reference in a source document may therefore in some cases correspond to two array positions in a DOMString (a high surrogate and a low surrogate). Note: Even though the DOM defines the name of the string type to be DOMString, bindings may used different names. For, example for Java, DOMString is bound to the String type because it also uses UTF-16 as its encoding. Note: As of August 1998, the OMG IDL specification included a wstring type. However, that definition did not meet the interoperability criteria of the DOM API since it relied on encoding negotiation to decide the width of a character. 1.1.6. Case sensitivity in the DOM The DOM has many interfaces that imply string matching. HTML processors generally assume an uppercase (less often, lowercase) normalization of names for such things as elements, while XML is explicitly case sensitive. For the purposes of the DOM, string matching takes place on a character code by character code basis, on the 16 bit value of a DOMString. As such, the DOM assumes that any normalizations will take place in the processor, before the DOM structures are built. This then raises the issue of exactly what normalizations occur. The W3C I18N working group is in the process of defining exactly which normalizations are necessary for applications implementing the DOM. 1.2. Fundamental Interfaces The interfaces within this section are considered fundamental, and must be fully implemented by all conforming implementations of the DOM, including all HTML DOM implementations. Exception DOMException 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 situation, such as out-of-bound errors when using NodeList. Implementations may raise other exceptions under other circumstances. For example, implementations may raise an implementation-dependent exception if a null argument is passed. 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. IDL Definition exception DOMException { unsigned short code; }; // ExceptionCode const unsigned short INDEX_SIZE_ERR = 1; const unsigned short DOMSTRING_SIZE_ERR = 2; const unsigned short HIERARCHY_REQUEST_ERR = 3; const unsigned short WRONG_DOCUMENT_ERR = 4; const unsigned short INVALID_CHARACTER_ERR = 5; const unsigned short NO_DATA_ALLOWED_ERR = 6; const unsigned short NO_MODIFICATION_ALLOWED_ERR = 7; const unsigned short NOT_FOUND_ERR = 8; const unsigned short NOT_SUPPORTED_ERR = 9; const unsigned short INUSE_ATTRIBUTE_ERR = 10; Definition group ExceptionCode An integer indicating the type of error generated. Defined Constants INDEX_SIZE_ERR If index or size is negative, or greater than the allowed value DOMSTRING_SIZE_ERR If the specified range of text does not fit into a DOMString HIERARCHY_REQUEST_ERR If any node is inserted somewhere it doesn't belong If a node is used in a different WRONG_DOCUMENT_ERR document than the one that created it (that doesn't support it) INVALID_CHARACTER_ERR If an invalid character is specified, such as in a name. NO_DATA_ALLOWED_ERR If data is specified for a node which does not support data If an attempt is made to modify NO_MODIFICATION_ALLOWED_ERR an object where modifications are not allowed If an attempt was made to NOT_FOUND_ERR reference a node in a context where it does not exist If the implementation does not NOT_SUPPORTED_ERR support the type of object requested If an attempt is made to add an INUSE_ATTRIBUTE_ERR attribute that is already inuse elsewhere Interface DOMImplementation The DOMImplementation interface provides a number of methods for performing operations that are independent of any particular instance of the document object model. The DOM Level 1 does not specify a way of creating a document instance, and hence document creation is an operation specific to an implementation. Future Levels of the DOM specification are expected to provide methods for creating documents directly. IDL Definition interface DOMImplementation { boolean hasFeature(in DOMString feature, in DOMString version); }; Methods hasFeature Test if the DOM implementation implements a specific feature. Parameters feature The package name of the feature to test. In Level 1, the legal values are "HTML" and "XML" (case-insensitive). version This is the version number of the package name to test. In Level 1, this is the string "1.0". If the version is not specified, supporting any version of the feature will cause the method to return true. Return Value true if the feature is implemented in the specified version, false otherwise. This method raises no exceptions. Interface DocumentFragment 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 fulfil 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 insertBefore() and appendChild(). IDL Definition interface DocumentFragment : Node { }; Interface Document 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. IDL Definition interface Document : Node { readonly attribute DocumentType doctype; readonly attribute DOMImplementation implementation; readonly attribute Element documentElement; Element createElement(in DOMString tagName) raises(DOMException); DocumentFragment createDocumentFragment(); Text createTextNode(in DOMString data); Comment createComment(in DOMString data); CDATASection createCDATASection(in DOMString data) raises(DOMException); ProcessingInstruction createProcessingInstruction(in DOMString target, in DOMString data) raises(DOMException); Attr createAttribute(in DOMString name) raises(DOMException); EntityReference createEntityReference(in DOMString name) raises(DOMException); NodeList getElementsByTagName(in DOMString tagname); }; Attributes doctype The Document Type Declaration (see DocumentType) associated with this document. For HTML documents as well as XML documents without a document type declaration this returns null. The DOM Level 1 does not support editing the Document Type Declaration, therefore docType cannot be altered in any way. implementation The DOMImplementation object that handles this document. A DOM application may use objects from multiple implementations. documentElement This is a convenience attribute that allows direct access to the child node that is the root element of the document. For HTML documents, this is the element with the tagName "HTML". Methods createElement Creates an element of the type specified. Note that the instance returned implements the Element interface, so attributes can be specified directly on the returned object. Parameters tagName The name of the element type to instantiate. For XML, this is case-sensitive. For HTML, the tagName parameter may be provided in any case, but it must be mapped to the canonical uppercase form by the DOM implementation. Return Value A new Element object. Exceptions DOMException INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. createDocumentFragment Creates an empty DocumentFragment object. Return Value A new DocumentFragment. This method has no parameters. This method raises no exceptions. createTextNode Creates a Text node given the specified string. Parameters data The data for the node. Return Value The new Text object. This method raises no exceptions. createComment Creates a Comment node given the specified string. Parameters data The data for the node. Return Value The new Comment object. This method raises no exceptions. createCDATASection Creates a CDATASection node whose value is the specified string. Parameters data The data for the CDATASection contents. Return Value The new CDATASection object. Exceptions DOMException NOT_SUPPORTED_ERR: Raised if this document is an HTML document. createProcessingInstruction Creates a ProcessingInstruction node given the specified name and data strings. Parameters target The target part of the processing instruction. data The data for the node. Return Value The new ProcessingInstruction object. Exceptions DOMException INVALID_CHARACTER_ERR: Raised if an invalid character is specified. NOT_SUPPORTED_ERR: Raised if this document is an HTML document. createAttribute Creates an Attr of the given name. Note that the Attr instance can then be set on an Element using the setAttribute method. Parameters name The name of the attribute. Return Value A new Attr object. Exceptions DOMException INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. createEntityReference Creates an EntityReference object. Parameters name The name of the entity to reference. Return Value The new EntityReference object. Exceptions DOMException INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. NOT_SUPPORTED_ERR: Raised if this document is an HTML document. getElementsByTagName Returns a NodeList of all the Elements with a given tag name in the order in which they would be encountered in a preorder traversal of the Document tree. Parameters tagname The name of the tag to match on. The special value "*" matches all tags. Return Value A new NodeList object containing all the matched Elements. This method raises no exceptions. Interface Node 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. IDL Definition interface Node { // NodeType const unsigned short ELEMENT_NODE = 1; const unsigned short ATTRIBUTE_NODE = 2; const unsigned short TEXT_NODE = 3; const unsigned short CDATA_SECTION_NODE = 4; const unsigned short ENTITY_REFERENCE_NODE = 5; const unsigned short ENTITY_NODE = 6; const unsigned short PROCESSING_INSTRUCTION_NODE = 7; const unsigned short COMMENT_NODE = 8; const unsigned short DOCUMENT_NODE = 9; const unsigned short DOCUMENT_TYPE_NODE = 10; const unsigned short DOCUMENT_FRAGMENT_NODE = 11; const unsigned short NOTATION_NODE = 12; readonly attribute DOMString nodeName; attribute DOMString nodeValue; // raises(DOMException) on setting // raises(DOMException) on retrieval readonly attribute unsigned short nodeType; readonly attribute Node parentNode; readonly attribute NodeList childNodes; readonly attribute Node firstChild; readonly attribute Node lastChild; readonly attribute Node previousSibling; readonly attribute Node nextSibling; readonly attribute NamedNodeMap attributes; readonly attribute Document ownerDocument; Node insertBefore(in Node newChild, in Node refChild) raises(DOMException); Node replaceChild(in Node newChild, in Node oldChild) raises(DOMException); Node removeChild(in Node oldChild) raises(DOMException); Node appendChild(in Node newChild) raises(DOMException); boolean hasChildNodes(); Node cloneNode(in boolean deep); }; Definition group NodeType An integer indicating which type of node this is. Defined Constants ELEMENT_NODE The node is a Element. ATTRIBUTE_NODE The node is an Attr. TEXT_NODE The node is a Text node. CDATA_SECTION_NODE The node is a CDATASection. ENTITY_REFERENCE_NODE The node is an EntityReference. ENTITY_NODE The node is an Entity. PROCESSING_INSTRUCTION_NODE The node is a ProcessingInstruction. COMMENT_NODE The node is a Comment. DOCUMENT_NODE The node is a Document. DOCUMENT_TYPE_NODE The node is a DocumentType. DOCUMENT_FRAGMENT_NODE The node is a DocumentFragment. NOTATION_NODE The node is a Notation. The values of nodeName, nodeValue, and attributes vary according to the node type as follows: nodeName nodeValue attributes Element tagName null NamedNodeMap Attr name of attribute value of null attribute Text #text content of null the text node CDATASection #cdata-section content of null the CDATA Section EntityReference name of entity null null referenced Entity entity name null null ProcessingInstructiontarget entire null content excluding the target Comment #comment content of null the comment Document #document null null DocumentType document type name null null DocumentFragment #document-fragment null null Notation notation name null null Attributes nodeName The name of this node, depending on its type; see the table above. nodeValue The value of this node, depending on its type; see the table above. Exceptions on setting DOMException NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. Exceptions on retrieval DOMException DOMSTRING_SIZE_ERR: Raised when it would return more characters than fit in a DOMString variable on the implementation platform. nodeType A code representing the type of the underlying object, as defined above. parentNode The parent of this node. All nodes, except Document, DocumentFragment, and Attr may have a parent. However, if a node has just been created and not yet added to the tree, or if it has been removed from the tree, this is null. childNodes A NodeList that contains all children of this node. If there are no children, this is a NodeList containing no nodes. The content of the returned NodeList is "live" in the sense that, for instance, changes to the children of the node object that it was created from are immediately reflected in the nodes returned by the NodeList accessors; it is not a static snapshot of the content of the node. This is true for every NodeList, including the ones returned by the getElementsByTagName method. firstChild The first child of this node. If there is no such node, this returns null. lastChild The last child of this node. If there is no such node, this returns null. previousSibling The node immediately preceding this node. If there is no such node, this returns null. nextSibling The node immediately following this node. If there is no such node, this returns null. attributes A NamedNodeMap containing the attributes of this node (if it is an Element) or null otherwise. ownerDocument The Document object associated with this node. This is also the Document object used to create new nodes. When this node is a Document this is null. Methods insertBefore Inserts the node newChild before the existing child node refChild. If refChild is null, insert newChild at the end of the list of children. If newChild is a DocumentFragment object, all of its children are inserted, in the same order, before refChild. If the newChild is already in the tree, it is first removed. Parameters newChild The node to insert. refChild The reference node, i.e., the node before which the new node must be inserted. Return Value The node being inserted. Exceptions DOMException HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not allow children of the type of the newChild node, or if the node to insert is one of this node's ancestors. WRONG_DOCUMENT_ERR: Raised if newChild was created from a different document than the one that created this node. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if refChild is not a child of this node. replaceChild Replaces the child node oldChild with newChild in the list of children, and returns the oldChild node. If the newChild is already in the tree, it is first removed. Parameters newChild The new node to put in the child list. oldChild The node being replaced in the list. Return Value The node replaced. Exceptions DOMException HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not allow children of the type of the newChild node, or it the node to put in is one of this node's ancestors. WRONG_DOCUMENT_ERR: Raised if newChild was created from a different document than the one that created this node. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if oldChild is not a child of this node. removeChild Removes the child node indicated by oldChild from the list of children, and returns it. Parameters oldChild The node being removed. Return Value The node removed. Exceptions DOMException NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if oldChild is not a child of this node. appendChild Adds the node newChild to the end of the list of children of this node. If the newChild is already in the tree, it is first removed. Parameters newChild The node to add. If it is a DocumentFragment object, the entire contents of the document fragment are moved into the child list of this node Return Value The node added. Exceptions DOMException HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not allow children of the type of the newChild node, or if the node to append is one of this node's ancestors. WRONG_DOCUMENT_ERR: Raised if newChild was created from a different document than the one that created this node. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. hasChildNodes This is a convenience method to allow easy determination of whether a node has any children. Return Value true if the node has any children, false if the node has no children. This method has no parameters. This method raises no exceptions. cloneNode Returns a duplicate of this node, i.e., serves as a generic copy constructor for nodes. The duplicate node has no parent (parentNode returns null.). Cloning an Element copies all attributes and their values, including those generated by the XML processor to represent defaulted attributes, but this method does not copy any text it contains unless it is a deep clone, since the text is contained in a child Text node. Cloning any other type of node simply returns a copy of this node. Parameters deep If true, recursively clone the subtree under the specified node; if false, clone only the node itself (and its attributes, if it is an Element). Return Value The duplicate node. This method raises no exceptions. Interface NodeList The NodeList interface provides the abstraction of an ordered collection of nodes, without defining or constraining how this collection is implemented. The items in the NodeList are accessible via an integral index, starting from 0. IDL Definition interface NodeList { Node item(in unsigned long index); readonly attribute unsigned long length; }; Methods item Returns the indexth item in the collection. If index is greater than or equal to the number of nodes in the list, this returns null. Parameters index Index into the collection. Return Value The node at the indexth position in the NodeList, or null if that is not a valid index. This method raises no exceptions. Attributes length The number of nodes in the list. The range of valid child node indices is 0 to length-1 inclusive. Interface NamedNodeMap 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. IDL Definition interface NamedNodeMap { Node getNamedItem(in DOMString name); Node setNamedItem(in Node arg) raises(DOMException); Node removeNamedItem(in DOMString name) raises(DOMException); Node item(in unsigned long index); readonly attribute unsigned long length; }; Methods getNamedItem Retrieves a node specified by name. Parameters name Name of a node to retrieve. Return Value A Node (of any type) with the specified name, or null if the specified name did not identify any node in the map. This method raises no exceptions. setNamedItem Adds a node using its nodeName attribute. As the nodeName attribute is used to derive the name which the node must be stored under, multiple nodes of certain types (those that have a "special" string value) cannot be stored as the names would clash. This is seen as preferable to allowing nodes to be aliased. Parameters arg A node to store in a named node map. The node will later be accessible using the value of the nodeName attribute of the node. If a node with that name is already present in the map, it is replaced by the new one. Return Value If the new Node replaces an existing node with the same name the previously existing Node is returned, otherwise null is returned. Exceptions DOMException WRONG_DOCUMENT_ERR: Raised if arg was created from a different document than the one that created the NamedNodeMap. NO_MODIFICATION_ALLOWED_ERR: Raised if this NamedNodeMap is readonly. INUSE_ATTRIBUTE_ERR: Raised if arg is an Attr that is already an attribute of another Element object. The DOM user must explicitly clone Attr nodes to re-use them in other elements. removeNamedItem Removes a node specified by name. If the removed node is an Attr with a default value it is immediately replaced. Parameters name The name of a node to remove. Return Value The node removed from the map or null if no node with such a name exists. Exceptions DOMException NOT_FOUND_ERR: Raised if there is no node named name in the map. item Returns the indexth item in the map. If index is greater than or equal to the number of nodes in the map, this returns null. Parameters index Index into the map. Return Value The node at the indexth position in the NamedNodeMap, or null if that is not a valid index. This method raises no exceptions. Attributes length The number of nodes in the map. The range of valid child node indices is 0 to length-1 inclusive. Interface CharacterData 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. IDL Definition interface CharacterData : Node { attribute DOMString data; // raises(DOMException) on setting // raises(DOMException) on retrieval readonly attribute unsigned long length; DOMString substringData(in unsigned long offset, in unsigned long count) raises(DOMException); void appendData(in DOMString arg) raises(DOMException); void insertData(in unsigned long offset, in DOMString arg) raises(DOMException); void deleteData(in unsigned long offset, in unsigned long count) raises(DOMException); void replaceData(in unsigned long offset, in unsigned long count, in DOMString arg) raises(DOMException); }; Attributes data The character data of the node that implements this interface. The DOM implementation may not put arbitrary limits on the amount of data that may be stored in a CharacterData node. However, implementation limits may mean that the entirety of a node's data may not fit into a single DOMString. In such cases, the user may call substringData to retrieve the data in appropriately sized pieces. Exceptions on setting DOMException NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. Exceptions on retrieval DOMException DOMSTRING_SIZE_ERR: Raised when it would return more characters than fit in a DOMString variable on the implementation platform. length The number of characters that are available through data and the substringData method below. This may have the value zero, i.e., CharacterData nodes may be empty. Methods substringData Extracts a range of data from the node. Parameters offset Start offset of substring to extract. count The number of characters to extract. Return Value The specified substring. If the sum of offset and count exceeds the length, then all characters to the end of the data are returned. Exceptions DOMException INDEX_SIZE_ERR: Raised if the specified offset is negative or greater than the number of characters in data, or if the specified count is negative. DOMSTRING_SIZE_ERR: Raised if the specified range of text does not fit into a DOMString. appendData Append the string to the end of the character data of the node. Upon success, data provides access to the concatenation of data and the DOMString specified. Parameters arg The DOMString to append. Exceptions DOMException NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. This method returns nothing. insertData Insert a string at the specified character offset. Parameters offset The character offset at which to insert. arg The DOMString to insert. Exceptions DOMException INDEX_SIZE_ERR: Raised if the specified offset is negative or greater than the number of characters in data. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. This method returns nothing. deleteData Remove a range of characters from the node. Upon success, data and length reflect the change. Parameters offset The offset from which to remove characters. count The number of characters to delete. If the sum of offset and count exceeds length then all characters from offset to the end of the data are deleted. Exceptions DOMException INDEX_SIZE_ERR: Raised if the specified offset is negative or greater than the number of characters in data, or if the specified count is negative. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. This method returns nothing. replaceData Replace the characters starting at the specified character offset with the specified string. Parameters offset The offset from which to start replacing. count The number of characters to replace. If the sum of offset and count exceeds length, then all characters to the end of the data are replaced (i.e., the effect is the same as a remove method call with the same range, followed by an append method invocation). arg The DOMString with which the range must be replaced. Exceptions DOMException INDEX_SIZE_ERR: Raised if the specified offset is negative or greater than the number of characters in data, or if the specified count is negative. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. This method returns nothing. Interface Attr The Attr interface represents an attribute in an Element object. Typically the allowable values for the attribute are defined in a document type definition. 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 nodeValue attribute on the Attr instance can also be used to retrieve the string version of the attribute's value(s). In XML, where the value of an attribute can contain entity references, the child nodes of the Attr node provide a representation in which entity references are not expanded. These child nodes may be either Text or EntityReference nodes. Because the attribute type may be unknown, there are no tokenized attribute values. IDL Definition interface Attr : Node { readonly attribute DOMString name; readonly attribute boolean specified; attribute DOMString value; }; Attributes name Returns the name of this attribute. specified If this attribute was explicitly given a value in the original document, this is true; otherwise, it is false. Note that the implementation is in charge of this attribute, not the user. If the user changes the value of the attribute (even if it ends up having the same value as the default value) then the specified flag is automatically flipped to true. To re-specify the attribute as the default value from the DTD, the user must delete the attribute. The implementation will then make a new attribute available with specified set to false and the default value (if one exists). In summary: + If the attribute has an assigned value in the document then specified is true, and the value is the assigned value. + If the attribute has no assigned value in the document and has a default value in the DTD, then specified is false, and the value is the default value in the DTD. + If the attribute has no assigned value in the document and has a value of #IMPLIED in the DTD, then the attribute does not appear in the structure model of the document. value On retrieval, the value of the attribute is returned as a string. Character and general entity references are replaced with their values. On setting, this creates a Text node with the unparsed contents of the string. Interface Element By far the vast majority of objects (apart from text) that authors encounter when traversing a document are Element nodes. Assume the following XML document: When represented using DOM, the top node is an Element node for "elementExample", which contains two child Element nodes, one for "subelement1" and one for "subelement2". "subelement1" contains no child nodes. Elements may have attributes associated with them; since the Element interface inherits from Node, the generic Node interface method getAttributes 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. IDL Definition interface Element : Node { readonly attribute DOMString tagName; DOMString getAttribute(in DOMString name); void setAttribute(in DOMString name, in DOMString value) raises(DOMException); void removeAttribute(in DOMString name) raises(DOMException); Attr getAttributeNode(in DOMString name); Attr setAttributeNode(in Attr newAttr) raises(DOMException); Attr removeAttributeNode(in Attr oldAttr) raises(DOMException); NodeList getElementsByTagName(in DOMString name); void normalize(); }; Attributes tagName The name of the element. For example, in: ... , tagName has the value "elementExample". Note that this is case-preserving in XML, as are all of the operations of the DOM. The HTML DOM returns the tagName of an HTML element in the canonical uppercase form, regardless of the case in the source HTML document. Methods getAttribute Retrieves an attribute value by name. Parameters name The name of the attribute to retrieve. Return Value The Attr value as a string, or the empty string if that attribute does not have a specified or default value. This method raises no exceptions. setAttribute Adds a new attribute. If an attribute with that name is already present in the element, its value is changed to be that of the value parameter. This value is a simple string, it is not parsed as it is being set. So any markup (such as syntax to be recognized as an entity reference) is treated as literal text, and needs to be appropriately escaped by the implementation when it is written out. In order to assign an attribute value that contains entity references, the user must create an Attr node plus any Text and EntityReference nodes, build the appropriate subtree, and use setAttributeNode to assign it as the value of an attribute. Parameters name The name of the attribute to create or alter. value Value to set in string form. Exceptions DOMException INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. This method returns nothing. removeAttribute Removes an attribute by name. If the removed attribute has a default value it is immediately replaced. Parameters name The name of the attribute to remove. Exceptions DOMException NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. This method returns nothing. getAttributeNode Retrieves an Attr node by name. Parameters name The name of the attribute to retrieve. Return Value The Attr node with the specified attribute name or null if there is no such attribute. This method raises no exceptions. setAttributeNode Adds a new attribute. If an attribute with that name is already present in the element, it is replaced by the new one. Parameters newAttr The Attr node to add to the attribute list. Return Value If the newAttr attribute replaces an existing attribute with the same name, the previously existing Attr node is returned, otherwise null is returned. Exceptions DOMException WRONG_DOCUMENT_ERR: Raised if newAttr was created from a different document than the one that created the element. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. INUSE_ATTRIBUTE_ERR: Raised if newAttr is already an attribute of another Element object. The DOM user must explicitly clone Attr nodes to re-use them in other elements. removeAttributeNode Removes the specified attribute. Parameters oldAttr The Attr node to remove from the attribute list. If the removed Attr has a default value it is immediately replaced. Return Value The Attr node that was removed. Exceptions DOMException NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if oldAttr is not an attribute of the element. getElementsByTagName Returns a NodeList of all descendant elements with a given tag name, in the order in which they would be encountered in a preorder traversal of the Element tree. Parameters name The name of the tag to match on. The special value "*" matches all tags. Return Value A list of matching Element nodes. This method raises no exceptions. normalize Puts all Text nodes in the full depth of the sub-tree underneath this Element into a "normal" form where only markup (e.g., tags, comments, processing instructions, CDATA sections, and entity references) separates Text nodes, i.e., there are no adjacent Text nodes. This can be used to ensure that the DOM view of a document is the same as if it were saved and re-loaded, and is useful when operations (such as XPointer lookups) that depend on a particular document tree structure are to be used. This method has no parameters. This method returns nothing. This method raises no exceptions. Interface Text The Text interface represents the textual content (termed character data in XML) of an Element or Attr. If there is no markup inside an element's content, the text is contained in a single object implementing the Text interface that is the only child of the element. If there is markup, it is parsed into a list of elements and Text nodes that form the list of children of the element. When a document is first made available via the DOM, there is only one Text node for each block of text. Users may create adjacent Text nodes that represent the contents of a given element without any intervening markup, but should be aware that there is no way to represent the separations between these nodes in XML or HTML, so they will not (in general) persist between DOM editing sessions. The normalize() method on Element merges any such adjacent Text objects into a single node for each block of text; this is recommended before employing operations that depend on a particular document structure, such as navigation with XPointers. IDL Definition interface Text : CharacterData { Text splitText(in unsigned long offset) raises(DOMException); }; Methods splitText Breaks this Text node into two Text nodes at the specified offset, keeping both in the tree as siblings. This node then only contains all the content up to the offset point. And a new Text node, which is inserted as the next sibling of this node, contains all the content at and after the offset point. Parameters offset The offset at which to split, starting from 0. Return Value The new Text node. Exceptions DOMException INDEX_SIZE_ERR: Raised if the specified offset is negative or greater than the number of characters in data. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. Interface Comment This represents the content of a comment, i.e., all the characters between the starting ''. 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. IDL Definition interface Comment : CharacterData { }; 1.3. Extended Interfaces The interfaces defined here form part of the DOM Level 1 Core specification, but objects that expose these interfaces will never be encountered in a DOM implementation that deals only with HTML. As such, HTML-only DOM implementations do not need to have objects that implement these interfaces. Interface CDATASection 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 can not be nested. The primary purpose is for including material such as XML fragments, without needing to escape all the delimiters. The DOMString attribute of the Text node 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 the CharacterData interface through the Text interface. Adjacent CDATASections nodes are not merged by use of the Element.normalize() method. IDL Definition interface CDATASection : Text { }; Interface DocumentType Each Document has a doctype attribute whose value is either null or a DocumentType object. The DocumentType interface in the DOM Level 1 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 scheme efforts on DTD representation are not clearly understood as of this writing. The DOM Level 1 doesn't support editing DocumentType nodes. IDL Definition interface DocumentType : Node { readonly attribute DOMString name; readonly attribute NamedNodeMap entities; readonly attribute NamedNodeMap notations; }; Attributes name The name of DTD; i.e., the name immediately following the DOCTYPE keyword. entities A NamedNodeMap containing the general entities, both external and internal, declared in the DTD. Duplicates are discarded. For example in: ]> the interface provides access to foo and bar but not baz. Every node in this map also implements the Entity interface. The DOM Level 1 does not support editing entities, therefore entities cannot be altered in any way. notations A NamedNodeMap containing the notations declared in the DTD. Duplicates are discarded. Every node in this map also implements the Notation interface. The DOM Level 1 does not support editing notations, therefore notations cannot be altered in any way. Interface Notation This interface represents a notation declared in the DTD. A notation either declares, by name, the format of an unparsed entity (see section 4.7 of the XML 1.0 specification), or is used for formal declaration of Processing Instruction targets (see section 2.6 of the XML 1.0 specification). The nodeName attribute inherited from Node is set to the declared name of the notation. The DOM Level 1 does not support editing Notation nodes; they are therefore readonly. A Notation node does not have any parent. IDL Definition interface Notation : Node { readonly attribute DOMString publicId; readonly attribute DOMString systemId; }; Attributes publicId The public identifier of this notation. If the public identifier was not specified, this is null. systemId The system identifier of this notation. If the system identifier was not specified, this is null. Interface Entity This interface represents an entity, either parsed or unparsed, in an XML document. Note that this models the entity itself not the entity declaration. Entity declaration modeling has been left for a later Level of the DOM specification. 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 external 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 value of the entity may not be available. When the replacement value is available, the corresponding Entity node's child list represents the structure of that replacement text. Otherwise, the child list is empty. The resolution of the children of the Entity (the replacement value) may be lazily evaluated; actions by the user (such as calling the childNodes method on the Entity Node) are assumed to trigger the evaluation. The DOM Level 1 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. All the descendants of an Entity node are readonly. An Entity node does not have any parent. IDL Definition interface Entity : Node { readonly attribute DOMString publicId; readonly attribute DOMString systemId; readonly attribute DOMString notationName; }; Attributes publicId The public identifier associated with the entity, if specified. If the public identifier was not specified, this is null. systemId The system identifier associated with the entity, if specified. If the system identifier was not specified, this is null. notationName For unparsed entities, the name of the notation for the entity. For parsed entities, this is null. Interface EntityReference EntityReference objects may be inserted into the structure model when an entity reference is in the source document, or when the user wishes to insert an entity reference. 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 structure model, instead of providing EntityReference objects. If it does provide such objects, then for a given EntityReference node, it may be that there is no Entity node representing the referenced entity; but if such an Entity exists, then the child list of the EntityReference node is the same as that of the Entity node. As with the Entity node, all descendants of the EntityReference are readonly. The resolution of the children of the EntityReference (the replacement value of the referenced Entity) may be lazily evaluated; actions by the user (such as calling the childNodes method on the EntityReference node) are assumed to trigger the evaluation. IDL Definition interface EntityReference : Node { }; Interface ProcessingInstruction The ProcessingInstruction interface represents a "processing instruction", used in XML as a way to keep processor-specific information in the text of the document. IDL Definition interface ProcessingInstruction : Node { readonly attribute DOMString target; attribute DOMString data; // raises(DOMException) on setting }; Attributes target The target of this processing instruction. XML defines this as being the first token following the markup that begins the processing instruction. data The content of this processing instruction. This is from the first non white space character after the target to the character immediately preceding the ?>. Exceptions on setting DOMException NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. 2. Document Object Model (HTML) Level 1 Editors Mike Champion, ArborText Vidur Apparao, Netscape Scott Isaacs, Microsoft (until January 1998) Chris Wilson, Microsoft (after January 1998) Ian Jacobs, W3C 2.1. Introduction This section extends the Level 1 Core API to describe objects and methods specific to HTML documents. In general, the functionality needed to manipulate hierarchical document structures, elements, and attributes will be found in the core section; functionality that depends on the specific elements defined in HTML will be found in this section. The goals of the HTML-specific DOM API are: * to specialize and add functionality that relates specifically to HTML documents and elements. * to address issues of backwards compatibility with the "DOM Level 0". * to provide convenience mechanisms, where appropriate, for common and frequent operations on HTML documents. The term "DOM Level 0" refers to a mix (not formally specified) of HTML document functionalities offered by Netscape Navigator version 3.0 and Microsoft Internet Explorer version 3.0. In some cases, attributes or methods have been included for reasons of backward compatibility with "DOM Level 0". The key differences between the core DOM and the HTML application of DOM is that the HTML Document Object Model exposes a number of convenience methods and properties that are consistent with the existing models and are more appropriate to script writers. In many cases, these enhancements are not applicable to a general DOM because they rely on the presence of a predefined DTD. For DOM Level 1, the transitional and frameset DTDs for HTML 4.0 are assumed. Interoperability between implementations is only guaranteed for elements and attributes that are specified in these DTDs. More specifically, this document includes the following specializations for HTML: * An HTMLDocument interface, derived from the core Document interface. HTMLDocument specifies the operations and queries that can be made on a HTML document. * An HTMLElement interface, derived from the core Element interface. HTMLElement specifies the operations and queries that can be made on any HTML element. Methods on HTMLElement include those that allow for the retrieval and modification of attributes that apply to all HTML elements. * Specializations for all HTML elements that have attributes that extend beyond those specified in the HTMLElement interface. For all such attributes, the derived interface for the element contains explicit methods for setting and getting the values. The DOM Level 1 does not include mechanisms to access and modify style specified through CSS 1. Furthermore, it does not define an event model for HTML documents. This functionality is planned to be specified in a future Level of this specification. 2.2. HTML Application of Core DOM 2.2.1. Naming Conventions The HTML DOM follows a naming convention for properties, methods, events, collections, and data types. All names are defined as one or more English words concatenated together to form a single string. Properties and Methods The property or method name starts with the initial keyword in lowercase, and each subsequent word starts with a capital letter. For example, a property that returns document meta information such as the date the file was created might be named "fileDateCreated". In the ECMAScript binding, properties are exposed as properties of a given object. In Java, properties are exposed with get and set methods. Non-HTML 4.0 interfaces and attributes While most of the interfaces defined below can be mapped directly to elements defined in the HTML 4.0 Recommendation, some of them cannot. Similarly, not all attributes listed below have counterparts in the HTML 4.0 specification (and some do, but have been renamed to avoid conflicts with scripting languages). Interfaces and attribute definitions that have links to the HTML 4.0 specification have corresponding element and attribute definitions there; all others are added by this specification, either for convenience or backwards compatibility with "DOM Level 0" implementations. 2.3. Miscellaneous Object Definitions Interface HTMLCollection 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. Note: Collections in the HTML DOM are assumed to be live meaning that they are automatically updated when the underlying document is changed. IDL Definition interface HTMLCollection { readonly attribute unsigned long length; Node item(in unsigned long index); Node namedItem(in DOMString name); }; Attributes length This attribute specifies the length or size of the list. Methods item This method retrieves a node specified by ordinal index. Nodes are numbered in tree order (depth-first traversal order). Parameters index The index of the node to be fetched. The index origin is 0. Return Value The Node at the corresponding position upon success. A value of null is returned if the index is out of range. This method raises no exceptions. namedItem This method retrieves a Node using a name. It first searches for a Node with a matching id attribute. If it doesn't find one, it then searches for a Node with a matching name attribute, but only on those elements that are allowed a name attribute. Parameters name The name of the Node to be fetched. Return Value The Node with a name or id attribute whose value corresponds to the specified string. Upon failure (e.g., no node with this name exists), returns null. This method raises no exceptions. 2.4. Objects related to HTML documents Interface HTMLDocument An HTMLDocument is the root of the HTML hierarchy and holds the entire content. Beside 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: o alinkColor o background o bgColor o fgColor o linkColor o vlinkColor IDL Definition interface HTMLDocument : Document { attribute DOMString title; readonly attribute DOMString referrer; readonly attribute DOMString domain; readonly attribute DOMString URL; attribute HTMLElement body; readonly attribute HTMLCollection images; readonly attribute HTMLCollection applets; readonly attribute HTMLCollection links; readonly attribute HTMLCollection forms; readonly attribute HTMLCollection anchors; attribute DOMString cookie; void open(); void close(); void write(in DOMString text); void writeln(in DOMString text); Element getElementById(in DOMString elementId); NodeList getElementsByName(in DOMString elementName); }; Attributes title The title of a document as specified by the TITLE element in the head of the document. referrer Returns the URI of the page that linked to this page. The value is an empty string if the user navigated to the page directly (not through a link, but, for example, via a bookmark). domain The domain name of the server that served the document, or a null string if the server cannot be identified by a domain name. URL The complete URI of the document. body The element that contains the content for the document. In documents with BODY contents, returns the BODY element, and in frameset documents, this returns the outermost FRAMESET element. images A collection of all the IMG elements in a document. The behavior is limited to IMG elements for backwards compatibility. applets A collection of all the OBJECT elements that include applets and APPLET (deprecated) elements in a document. links A collection of all AREA elements and anchor (A) elements in a document with a value for the href attribute. forms A collection of all the forms of a document. anchors A collection of all the anchor (A) elements in a document with a value for the name attribute.Note. For reasons of backwards compatibility, the returned set of anchors only contains those anchors created with the name attribute, not those created with the id attribute. cookie The cookies associated with this document. If there are none, the value is an empty string. Otherwise, the value is a string: a semicolon-delimited list of "name, value" pairs for all the cookies associated with the page. For example, name=value;expires=date. Methods open Note. This method and the ones following allow a user to add to or replace the structure model of a document using strings of unparsed HTML. At the time of writing alternate methods for providing similar functionality for both HTML and XML documents were being considered. The following methods may be deprecated at some point in the future in favor of a more general-purpose mechanism. Open a document stream for writing. If a document exists in the target, this method clears it. This method has no parameters. This method returns nothing. This method raises no exceptions. close Closes a document stream opened by open() and forces rendering. This method has no parameters. This method returns nothing. This method raises no exceptions. write Write a string of text to a document stream opened by open(). The text is parsed into the document's structure model. Parameters text The string to be parsed into some structure in the document structure model. This method returns nothing. This method raises no exceptions. writeln Write a string of text followed by a newline character to a document stream opened by open(). The text is parsed into the document's structure model. Parameters text The string to be parsed into some structure in the document structure model. This method returns nothing. This method raises no exceptions. getElementById Returns the Element whose id is given by elementId. If no such element exists, returns null. Behavior is not defined if more than one element has this id. Parameters elementId The unique id value for an element. Return Value The matching element. This method raises no exceptions. getElementsByName Returns the (possibly empty) collection of elements whose name value is given by elementName. Parameters elementName The name attribute value for an element. Return Value The matching elements. This method raises no exceptions. 2.5. HTML Elements 2.5.1. Property Attributes HTML attributes are exposed as properties on the element object. The name of the exposed property always uses the naming conventions, and is independent of the case of the attribute in the source document. The data type of the property is determined by the type of the attribute as determined by the HTML 4.0 transitional and frameset DTDs. The attributes have the semantics (including case-sensitivity) given in the HTML 4.0 specification. The attributes are exposed as properties for compatibility with "DOM Level 0". This usage is deprecated because it can not be generalized to all possible attribute names, as is required both for XML and potentially for future versions of HTML. We recommend the use of generic methods on the core Element interface for setting, getting and removing attributes. DTD Data Type Object Model Data Type CDATA DOMString Value list (e.g., (left | right | center)) DOMString one-value Value list (e.g., (border)) boolean Number long int The return value of an attribute that has a data type that is a value list is always capitalized, independent of the case of the value in the source document. For example, if the value of the align attribute on a P element is "left" then it is returned as "Left". For attributes with the CDATA data type, the case of the return value is that given in the source document. 2.5.2. Naming Exceptions To avoid name-space conflicts, an attribute with the same name as a keyword in one of our chosen binding languages is prefixed. For HTML, the prefix used is "html". For example, the for attribute of the LABEL element collides with loop construct naming conventions and is renamed htmlFor. 2.5.3. Exposing Element Type Names (tagName) The element type names exposed through a property are in uppercase. For example, the body element type name is exposed through the "tagName" property as "BODY". 2.5.4. The HTMLElement interface Interface HTMLElement 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: o HEAD o special: SUB, SUP, SPAN, BDO o font: TT, I, B, U, S, STRIKE, BIG, SMALL o phrase: EM, STRONG, DFN, CODE, SAMP, KBD, VAR, CITE, ACRONYM, ABBR o list: DD, DT o NOFRAMES, NOSCRIPT o ADDRESS, CENTER Note. The style attribute for this interface is reserved for future usage. IDL Definition interface HTMLElement : Element { attribute DOMString id; attribute DOMString title; attribute DOMString lang; attribute DOMString dir; attribute DOMString className; }; Attributes id The element's identifier. See the id attribute definition in HTML 4.0. title The element's advisory title. See the title attribute definition in HTML 4.0. lang Language code defined in RFC 1766. See the lang attribute definition in HTML 4.0. dir Specifies the base direction of directionally neutral text and the directionality of tables. See the dir attribute definition in HTML 4.0. className The class attribute of the element. This attribute has been renamed due to conflicts with the "class" keyword exposed by many languages. See the class attribute definition in HTML 4.0. 2.5.5. Object definitions Interface HTMLHtmlElement Root of an HTML document. See the HTML element definition in HTML 4.0. IDL Definition interface HTMLHtmlElement : HTMLElement { attribute DOMString version; }; Attributes version Version information about the document's DTD. See the version attribute definition in HTML 4.0. This attribute is deprecated in HTML 4.0. Interface HTMLHeadElement Document head information. See the HEAD element definition in HTML 4.0. IDL Definition interface HTMLHeadElement : HTMLElement { attribute DOMString profile; }; Attributes profile URI designating a metadata profile. See the profile attribute definition in HTML 4.0. Interface HTMLLinkElement 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 4.0. IDL Definition interface HTMLLinkElement : HTMLElement { attribute boolean disabled; attribute DOMString charset; attribute DOMString href; attribute DOMString hreflang; attribute DOMString media; attribute DOMString rel; attribute DOMString rev; attribute DOMString target; attribute DOMString type; }; Attributes disabled Enables/disables the link. This is currently only used for style sheet links, and may be used to activate or deactivate style sheets. charset The character encoding of the resource being linked to. See the charset attribute definition in HTML 4.0. href The URI of the linked resource. See the href attribute definition in HTML 4.0. hreflang Language code of the linked resource. See the hreflang attribute definition in HTML 4.0. media Designed for use with one or more target media. See the media attribute definition in HTML 4.0. rel Forward link type. See the rel attribute definition in HTML 4.0. rev Reverse link type. See the rev attribute definition in HTML 4.0. target Frame to render the resource in. See the target attribute definition in HTML 4.0. type Advisory content type. See the type attribute definition in HTML 4.0. Interface HTMLTitleElement The document title. See the TITLE element definition in HTML 4.0. IDL Definition interface HTMLTitleElement : HTMLElement { attribute DOMString text; }; Attributes text The specified title as a string. Interface HTMLMetaElement This contains generic meta-information about the document. See the META element definition in HTML 4.0. IDL Definition interface HTMLMetaElement : HTMLElement { attribute DOMString content; attribute DOMString httpEquiv; attribute DOMString name; attribute DOMString scheme; }; Attributes content Associated information. See the content attribute definition in HTML 4.0. httpEquiv HTTP response header name. See the http-equiv attribute definition in HTML 4.0. name Meta information name. See the name attribute definition in HTML 4.0. scheme Select form of content. See the scheme attribute definition in HTML 4.0. Interface HTMLBaseElement Document base URI. See the BASE element definition in HTML 4.0. IDL Definition interface HTMLBaseElement : HTMLElement { attribute DOMString href; attribute DOMString target; }; Attributes href The base URI See the href attribute definition in HTML 4.0. target The default target frame. See the target attribute definition in HTML 4.0. Interface HTMLIsIndexElement This element is used for single-line text input. See the ISINDEX element definition in HTML 4.0. This element is deprecated in HTML 4.0. IDL Definition interface HTMLIsIndexElement : HTMLElement { readonly attribute HTMLFormElement form; attribute DOMString prompt; }; Attributes form Returns the FORM element containing this control. Returns null if this control is not within the context of a form. prompt The prompt message. See the prompt attribute definition in HTML 4.0. This attribute is deprecated in HTML 4.0. Interface HTMLStyleElement Style information. A more detailed style sheet object model is planned to be defined in a separate document. See the STYLE element definition in HTML 4.0. IDL Definition interface HTMLStyleElement : HTMLElement { attribute boolean disabled; attribute DOMString media; attribute DOMString type; }; Attributes disabled Enables/disables the style sheet. media Designed for use with one or more target media. See the media attribute definition in HTML 4.0. type The style sheet language (Internet media type). See the type attribute definition in HTML 4.0. Interface HTMLBodyElement 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 4.0. IDL Definition interface HTMLBodyElement : HTMLElement { attribute DOMString aLink; attribute DOMString background; attribute DOMString bgColor; attribute DOMString link; attribute DOMString text; attribute DOMString vLink; }; Attributes aLink Color of active links (after mouse-button down, but before mouse-button up). See the alink attribute definition in HTML 4.0. This attribute is deprecated in HTML 4.0. background URI of the background texture tile image. See the background attribute definition in HTML 4.0. This attribute is deprecated in HTML 4.0. bgColor Document background color. See the bgcolor attribute definition in HTML 4.0. This attribute is deprecated in HTML 4.0. link Color of links that are not active and unvisited. See the link attribute definition in HTML 4.0. This attribute is deprecated in HTML 4.0. text Document text color. See the text attribute definition in HTML 4.0. This attribute is deprecated in HTML 4.0. vLink Color of links that have been visited by the user. See the vlink attribute definition in HTML 4.0. This attribute is deprecated in HTML 4.0. Interface HTMLFormElement The FORM element encompasses behavior similar to a collection and an element. It provides direct access to the contained input elements as well as the attributes of the form element. See the FORM element definition in HTML 4.0. IDL Definition interface HTMLFormElement : HTMLElement { readonly attribute HTMLCollection elements; readonly attribute long length; attribute DOMString name; attribute DOMString acceptCharset; attribute DOMString action; attribute DOMString enctype; attribute DOMString method; attribute DOMString target; void submit(); void reset(); }; Attributes elements Returns a collection of all control elements in the form. length The number of form controls in the form. name Names the form. acceptCharset List of character sets supported by the server. See the accept-charset attribute definition in HTML 4.0. action Server-side form handler. See the action attribute definition in HTML 4.0. enctype The content type of the submitted form, generally "application/x-www-form-urlencoded". See the enctype attribute definition in HTML 4.0. method HTTP method used to submit form. See the method attribute definition in HTML 4.0. target Frame to render the resource in. See the target attribute definition in HTML 4.0. Methods submit Submits the form. It performs the same action as a submit button. This method has no parameters. This method returns nothing. This method raises no exceptions. reset Restores a form element's default values. It performs the same action as a reset button. This method has no parameters. This method returns nothing. This method raises no exceptions. Interface HTMLSelectElement 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 4.0. IDL Definition interface HTMLSelectElement : HTMLElement { readonly attribute DOMString type; attribute long selectedIndex; attribute DOMString value; readonly attribute long length; readonly attribute HTMLFormElement form; readonly attribute HTMLCollection options; attribute boolean disabled; attribute boolean multiple; attribute DOMString name; attribute long size; attribute long tabIndex; void add(in HTMLElement element, in HTMLElement before); void remove(in long index); void blur(); void focus(); }; Attributes type The type of control created. selectedIndex The ordinal index of the selected option. The value -1 is returned if no element is selected. If multiple options are selected, the index of the first selected option is returned. value The current form control value. length The number of options in this SELECT. form Returns the FORM element containing this control. Returns null if this control is not within the context of a form. options The collection of OPTION elements contained by this element. disabled The control is unavailable in this context. See the disabled attribute definition in HTML 4.0. multiple If true, multiple OPTION elements may be selected in this SELECT. See the multiple attribute definition in HTML 4.0. name Form control or object name when submitted with a form. See the name attribute definition in HTML 4.0. size Number of visible rows. See the size attribute definition in HTML 4.0. tabIndex Index that represents the element's position in the tabbing order. See the tabindex attribute definition in HTML 4.0. Methods add Add a new element to the collection of OPTION elements for this SELECT. Parameters element The element to add. before The element to insert before, or NULL for the head of the list. This method returns nothing. This method raises no exceptions. remove Remove an element from the collection of OPTION elements for this SELECT. Does nothing if no element has the given index. Parameters index The index of the item to remove. This method returns nothing. This method raises no exceptions. blur Removes keyboard focus from this element. This method has no parameters. This method returns nothing. This method raises no exceptions. focus Gives keyboard focus to this element. This method has no parameters. This method returns nothing. This method raises no exceptions.