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) is 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 creation and population
of a Document
object using only DOM API calls; loading
a Document
and saving it persistently is left
to the product that implements the DOM API.
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 childrenEntityReference
-- Element
,
ProcessingInstruction
, Comment
,
Text
, CDATASection
,
EntityReference
Element
-- Element
,
Text
, Comment
,
ProcessingInstruction
, CDATASection
,
EntityReference
Attr
-- Text
,
EntityReference
ProcessingInstruction
-- no childrenComment
-- no childrenText
-- no childrenCDATASection
-- no childrenEntity
-- Element
,
ProcessingInstruction
, Comment
,
Text
, CDATASection
,
EntityReference
Notation
-- no childrenThe DOM also specifies a NodeList
interface to handle
ordered lists of Node
s, such as the children of a
Node
, or the elements returned by the
getElementsByTagName
method of the Element
interface, and also a NamedNodeMap
interface to handle
unordered sets of nodes referenced by their name attribute, such as the
attributes of an Element
. NodeList
and
NamedNodeMap
objects in the DOM are "live", that is,
changes to the underlying document structure are reflected in all
relevant NodeList
and NamedNodeMap
objects.
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
NodeList
and NamedNodeMap
objects.
Finally, the interfaces Text
, Comment
, and
CDATASection
all inherit from the
CharacterData
interface.
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. 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 2 API does not define a standard
way to create DOMImplementation
objects; actual DOM
implementations must provide some proprietary way of bootstrapping
these DOM interfaces, and then all other objects can be built from
there.
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++) may require such support. These extensions will be the responsibility of those adapting the DOM API to a specific language, not the DOM WG.
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.
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.
DOMString
typeTo ensure interoperability, the DOM specifies the following:
DOMString
using UTF-16
(defined in Appendix C.3 of [UNICODE] and Amendment 1 of
[ISO-10646]).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 use different names. For,
example for Java, DOMString
is bound to the
String
type because it also uses UTF-16 as its
encoding.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.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 is performed purely
by binary comparison of the 16-bit units of the
DOMString
. As such, the DOM assumes that any
normalizations 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.
The DOM Level 2 supports XML namespaces [Namespaces] by augmenting several interfaces of the DOM Level 1 Core to allow creating and manipulating elements and attributes associated to a namespace.
As far as the DOM is concerned, special attributes used for declaring XML namespaces are still exposed and can be manipulated just like any other attribute. Moving a node within a document, using the DOM, in no case results in a change of its namespace prefix or namespace URI. Similarly, creating a node with a namespace prefix and namespace URI, or changing the namespace prefix of a node, does not result in any addition, removal, or modification of any special attributes for declaring the appropriate XML namespaces. Applications are therefore responsible for declaring every namespace in use when saving a document into XML.
The new methods, such as createElementNS
and
createAttributeNS
of the Document
interface,
are meant to be used by namespace aware applications. Simple
applications that do not use namespaces can use the DOM Level 1
methods, such as createElement
and
createAttribute
. Elements and attributes created in this
way do not have any namespace prefix or namespace URI.
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, unless otherwise specified.
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.
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;
An integer indicating the type of error generated.
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 |
WRONG_DOCUMENT_ERR | If a node is used in a different 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 |
NO_MODIFICATION_ALLOWED_ERR | If an attempt is made to modify an object where modifications are not allowed |
NOT_FOUND_ERR | If an attempt was made to reference a node in a context where it does not exist |
NOT_SUPPORTED_ERR | If the implementation does not support the type of object requested |
INUSE_ATTRIBUTE_ERR | If an attempt is made to add an attribute that is already inuse elsewhere |
The DOMImplementation
interface provides a
number of methods for performing operations that are independent
of any particular instance of the document object model.
interface DOMImplementation { boolean hasFeature(in DOMString feature, in DOMString version); // Introduced in DOM Level 2: DocumentType createDocumentType(in DOMString qualifiedName, in DOMString publicID, in DOMString systemID); // Introduced in DOM Level 2: Document createDocument(in DOMString namespaceURI, in DOMString qualifiedName, in DocumentType doctype) raises(DOMException); };
hasFeature
| The package name of the feature to test (case-insensitive). The legal values are defined throughout this specification. The DOM Level 2 includes "HTML", "XML", as well as the several others. | |||
| This is the version number of the package name to test. In
Level 2, this is the string "2.0". If the version is not specified,
supporting any version of the feature will cause the method to
return |
|
|
createDocumentType
introduced in DOM Level 2DocumentType
node. HTML-only DOM
implementations do not need to implement this method.
| The qualified name of the document type to be created. | |||
| The document type public identifier. | |||
| The document type system identifier. |
A new |
createDocument
introduced in DOM Level 2Document
object of the specified type
with its document element. HTML-only DOM implementations do not need to
implement this method.
| The namespace URI of
the document element to create, or | |||
| The qualified name of the document element to be created. | |||
| The type of document to be created or When |
WRONG_DOCUMENT_ERR: Raised if |
DocumentFragment
is a "lightweight" or "minimal"
Document
object. It is very common to want to be able to
extract a portion of a document's tree or to create a new fragment of a
document. Imagine implementing a user command like cut or rearranging a
document by moving fragments around. It is desirable to have an object
which can hold such fragments and it is quite natural to use a Node for
this purpose. While it is true that a Document
object could
fulfill this role, a Document
object can potentially be a
heavyweight object, depending on the underlying implementation. What is
really needed for this is a very lightweight object.
DocumentFragment
is such an object.
Furthermore, various operations -- such as inserting nodes as children
of another Node
-- may take DocumentFragment
objects as arguments; this results in all the child nodes of the
DocumentFragment
being moved to the child list of this
node.
The children of a DocumentFragment
node are zero or more
nodes representing the tops of any sub-trees defining the structure of
the document. DocumentFragment
nodes do not need to be
well-formed XML documents (although they do need to follow the rules
imposed upon well-formed XML parsed entities, which can have multiple top
nodes). For example, a DocumentFragment
might have only one
child and that child node could be a Text
node. Such a
structure model represents neither an HTML document nor a well-formed XML
document.
When a DocumentFragment
is inserted into a
Document
(or indeed any other Node
that may
take children) the children of the DocumentFragment
and not
the DocumentFragment
itself are inserted into the
Node
. This makes the DocumentFragment
very
useful when the user wishes to create nodes that are siblings; the
DocumentFragment
acts as the parent of these nodes so that
the user can use the standard methods from the Node
interface, such as insertBefore
and
appendChild
.
interface DocumentFragment : Node { };
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.
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); // Introduced in DOM Level 2: Node importNode(in Node importedNode, in boolean deep) raises(DOMException); // Introduced in DOM Level 2: Element createElementNS(in DOMString namespaceURI, in DOMString qualifiedName) raises(DOMException); // Introduced in DOM Level 2: Attr createAttributeNS(in DOMString namespaceURI, in DOMString qualifiedName) raises(DOMException); // Introduced in DOM Level 2: NodeList getElementsByTagNameNS(in DOMString namespaceURI, in DOMString localName); };
doctype
of type DocumentType
, readonlyDocumentType
)
associated with this document. For HTML documents as well as XML
documents without a document type declaration this returns
null
. The DOM Level 2 does not support editing the
Document Type Declaration, therefore docType
cannot be
altered in any way, including through the use of methods, such as
insertNode
or removeNode
, inherited from
Node
.
implementation
of type DOMImplementation
, readonlyDOMImplementation
object that handles this
document. A DOM application may use objects from multiple
implementations.
documentElement
of type Element
, readonly
createElement
Element
interface, so attributes
can be specified directly on the returned object.Attr
nodes representing them are automatically created and
attached to the element.createElementNS
method.
| The name of the element type to
instantiate. For XML, this is case-sensitive. For HTML, the
|
INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. |
createDocumentFragment
DocumentFragment
object.
A new |
createTextNode
createComment
createCDATASection
CDATASection
node whose value is
the specified string.
| The data for the |
The new |
NOT_SUPPORTED_ERR: Raised if this document is an HTML document. |
createProcessingInstruction
ProcessingInstruction
node given
the specified name and data strings.
The new |
INVALID_CHARACTER_ERR: Raised if an invalid character is specified. NOT_SUPPORTED_ERR: Raised if this document is an HTML document. |
createAttribute
Attr
of the given name.
Note that the Attr
instance
can then be set on an Element
using the
setAttribute
method. createAttributeNS
method.
| The name of the attribute. |
INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. |
createEntityReference
| The name of the entity to reference. |
The new |
INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. NOT_SUPPORTED_ERR: Raised if this document is an HTML document. |
getElementsByTagName
importNode
introduced in DOM Level 2parentNode
is null
). The
source node is not altered or removed from the original document; this
method creates a new copy of the source node.nodeName
and nodeType
, plus the
attributes related to namespaces (prefix and namespaces URI). As in the
cloneNode
operation on a Node
, the source
node is not altered.nodeType
, attempting to mirror the behavior expected if a
fragment of XML or HTML source was copied from one document to another,
recognizing that the two documents may have different DTDs in the XML
case. The following list describes the specifics for every type of
node.
Attr
nodes
are attached to the generated Element
. Default
attributes are not copied, though if the document
being imported into defines default attributes for this element
name, those are assigned. If importNode
deep
parameter was set to true
, the
descendants of the source element will be recursively imported
and the resulting nodes reassembled to form the corresponding
subtree.specified
flag is set to
true
on the generated Attr
. The
descendants of the the source Attr
are recursively
imported and the resulting nodes reassembled to form the
corresponding subtree.deep
parameter does not apply to
Attr
nodes; they always carry their children with
them when imported.CharacterData
copy their data
and
length
attributes from those of the source
node.EntityReference
itself is copied,
even if a deep
import is requested, since the
source and destination documents might have defined the entity
differently. If the document being imported into provides a
definition for this entity name, its value is assigned.Entity
nodes can be imported, however in the
current release of the DOM the DocumentType
is
readonly. Ability to add these imported nodes to a
DocumentType
will be considered for addition to a
future release of the DOM.publicID
, systemID
,
and notationName
attributes are copied. If a
deep
import is requested, the descendants of the
the source Entity
is recursively imported and the
resulting nodes reassembled to form the corresponding
subtree.target
and
data
values from those of the source node.Document
nodes cannot be imported.DocumentType
nodes cannot be imported.deep
option was set true
,
the descendants of the source element will be recursively
imported and the resulting nodes reassembled to form the
corresponding subtree. Otherwise, this simply generates an
empty DocumentFragment
.Notation
nodes be imported, however in the
current release of the DOM the DocumentType
is
readonly. Ability to add these imported nodes to a
DocumentType
will be considered for addition to a
future release of the DOM.publicID
, and
systemID
attributes are copied.deep
parameter does not apply to
Notation
nodes since they never have any
children.
| The node to import. | |||
|
| If |
The imported node that belongs to this
|
NOT_SUPPORTED_ERR: Raised if the type of node being imported is not supported. |
createElementNS
introduced in DOM Level 2
| The namespace URI of
the element to create. When it is | |||
| The qualified name of the element type to instantiate. |
A new
|
INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. |
createAttributeNS
introduced in DOM Level 2
| The namespace URI of
the attribute to create. When it is | |||
| The qualified name of the attribute to instantiate. |
A new
|
INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. |
getElementsByTagNameNS
introduced in DOM Level 2NodeList
of all the Element
s
with a given local name and
namespace URI in the order in which they would be encountered in a
preorder traversal of the Document
tree.
| The namespace URI of
the elements to match on. The special value "*" matches all
namespaces. When it is | |||
| The local name of the elements to match on. The special value "*" matches all local names. |
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.
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; // Modified in DOM Level 2: 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); // Introduced in DOM Level 2: boolean supports(in DOMString feature, in DOMString version); // Introduced in DOM Level 2: readonly attribute DOMString namespaceURI; // Introduced in DOM Level 2: attribute DOMString prefix; // raises(DOMException) on setting // Introduced in DOM Level 2: readonly attribute DOMString localName; };
An integer indicating which type of node this is.
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 attribute | null |
Text | #text | content of the text node | null |
CDATASection | #cdata-section | content of the CDATA Section | null |
EntityReference | name of entity referenced | null | null |
Entity | entity name | null | null |
ProcessingInstruction | target | entire content excluding the target | null |
Comment | #comment | content of the comment | null |
Document | #document | null | null |
DocumentType | document type name | null | null |
DocumentFragment | #document-fragment | null | null |
Notation | notation name | null | null |
nodeName
of type DOMString
, readonly
nodeValue
of type DOMString
null
, setting it has no
effect.
NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. |
DOMSTRING_SIZE_ERR: Raised when it would return more
characters than fit in a |
nodeType
of type unsigned short
, readonly
parentNode
of type Node
, readonlyAttr
, Document
,
DocumentFragment
, Entity
, and
Notation
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
of type NodeList
, readonlyNodeList
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
of type Node
, readonlynull
.
lastChild
of type Node
, readonlynull
.
previousSibling
of type Node
, readonlynull
.
nextSibling
of type Node
, readonlynull
.
attributes
of type NamedNodeMap
, readonlyNamedNodeMap
containing the
attributes of this node (if it is an Element
) or
null
otherwise.
ownerDocument
of type Document
, readonly, modified in DOM Level 2Document
object associated with this node. This
is also the Document
object used to create new nodes. When
this node is a Document
or a DocumentType
,
which is not used with any Document
yet, this is
null
.
namespaceURI
of type DOMString
, readonly, introduced in DOM Level 2null
if it is unspecified. When this node is
of any type other than ELEMENT_NODE
and
ATTRIBUTE_NODE
, this is always null
and
setting it has no effect.createElement
from the Document
interface,
this is null
.
prefix
of type DOMString
, introduced in DOM Level 2null
if it is unspecified. When this node
is of any type other than ELEMENT_NODE
and
ATTRIBUTE_NODE
this is always null
and
setting it has no effect.createElement
from the Document
interface,
this is null
.nodeName
attribute, which holds the qualified
name, as well as the tagName
and
name
attributes of the Element
and
Attr
interfaces, when applicable.
INVALID_CHARACTER_ERR: Raised if the specified prefix contains an invalid character. |
localName
of type DOMString
, readonly, introduced in DOM Level 2createElement
from the Document
interface,
and for nodes of any type other than ELEMENT_NODE
and
ATTRIBUTE_NODE
this is the same as the
nodeName
attribute.
insertBefore
newChild
before the
existing child node refChild
. If
refChild
is null
, insert
newChild
at the end of the list of children.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.
The node being inserted. |
HIERARCHY_REQUEST_ERR: Raised if this node is of a type
that does not allow children of the type of the WRONG_DOCUMENT_ERR: Raised if NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if |
replaceChild
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.
The node replaced. |
HIERARCHY_REQUEST_ERR: Raised if this node is of a type
that does not allow children of the type of the WRONG_DOCUMENT_ERR: Raised if NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if |
removeChild
oldChild
from
the list of children, and returns it.
| The node being removed. |
The node removed. |
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if |
appendChild
newChild
to the end of the list of
children of this node. If the newChild
is already in the
tree, it is first removed.
| The node to add. If it is a
|
The node added. |
HIERARCHY_REQUEST_ERR: Raised if this node is of a type
that does not allow children of the type of the WRONG_DOCUMENT_ERR: Raised if NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
hasChildNodes
|
|
cloneNode
parentNode
returns null
.).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.
|
| If |
The duplicate node. |
supports
introduced in DOM Level 2
| The package name of the feature to test. This is the same
name as what can be passed to the method | |||
| This is the version number of the package name to test. In
Level 2, version 1, this is the string "2.0". If the version is not
specified, supporting any version of the feature will cause the
method to return |
|
Returns |
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.
interface NodeList { Node item(in unsigned long index); readonly attribute unsigned long length; };
length
of type unsigned long
, readonlylength-1
inclusive.
item
index
th item in the collection.
If index
is greater than or equal to the number
of nodes in the list, this returns null
.
|
| Index into the collection. |
The node at the |
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
; NamedNodeMap
s 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.
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; // Introduced in DOM Level 2: Node getNamedItemNS(in DOMString namespaceURI, in DOMString localName); // Introduced in DOM Level 2: Node removeNamedItemNS(in DOMString namespaceURI, in DOMString name) raises(DOMException); };
length
of type unsigned long
, readonlylength-1
inclusive.
getNamedItem
setNamedItem
nodeName
attribute, which is
the qualified name when
applicable.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.
| A node to store in a named node map. The node will
later be accessible using the value of the
|
WRONG_DOCUMENT_ERR: Raised if NO_MODIFICATION_ALLOWED_ERR: Raised if this
INUSE_ATTRIBUTE_ERR: Raised if |
removeNamedItem
| The name of a node to remove. When this
|
The node removed from the map if a node with such a name exists. |
NOT_FOUND_ERR: Raised if there is no node named
|
item
index
th item in the map.
If index
is greater than or equal to the number
of nodes in the map, this returns null
.
|
| Index into the map. |
The node at the |
getNamedItemNS
introduced in DOM Level 2
| The namespace URI of
the node to retrieve. When it is | |||
| The local name of the node to retrieve. |
removeNamedItemNS
introduced in DOM Level 2
| The namespace URI of
the node to remove. When it is | |||
| The local name of the
node to remove. When this |
The node removed from the map if a node with such a local name and namespace URI exists. |
NOT_FOUND_ERR: Raised if there is no node named
|
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 offset
s in
this interface start from 0.
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); };
data
of type DOMString
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.
NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. |
DOMSTRING_SIZE_ERR: Raised when it would return more
characters than fit in a |
length
of type unsigned long
, readonlydata
and the
substringData
method below. This may have the value zero,
i.e., CharacterData
nodes may be empty.
substringData
|
| Start offset of substring to extract. | ||
|
| The number of 16-bit units to extract. |
The specified substring. If the sum of |
INDEX_SIZE_ERR: Raised if the specified DOMSTRING_SIZE_ERR: Raised if the specified range of text does
not fit into a |
appendData
data
provides access to the concatenation of
data
and the DOMString
specified.
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
insertData
INDEX_SIZE_ERR: Raised if the specified NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
deleteData
data
and length
reflect the change.
|
| The offset from which to start removing. | ||
|
| The number of 16-bit units to delete. If the sum of
|
INDEX_SIZE_ERR: Raised if the specified NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
replaceData
|
| The offset from which to start replacing. | ||
|
| The number of 16-bit units to replace. If the sum of
| ||
| The |
INDEX_SIZE_ERR: Raised if the specified NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
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.
interface Attr : Node { readonly attribute DOMString name; readonly attribute boolean specified; attribute DOMString value; // raises(DOMException) on setting // Introduced in DOM Level 2: readonly attribute Element ownerElement; };
name
of type DOMString
, readonly
specified
of type boolean
, readonlytrue
; 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).specified
is true
, and the value is the
assigned value.
specified
is false
,
and the value is the default value in the DTD.
value
of type DOMString
Text
node with the unparsed
contents of the string.
NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. |
ownerElement
of type Element
, readonly, introduced in DOM Level 2Element
node this attribute is attached to or
null
if this attribute is not in use.
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:
<elementExample id="demo"> <subelement1/> <subelement2><subsubelement/></subelement2> </elementExample>
When represented using DOM, the top node is a Document
node
containing 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 attribute attributes
may be used
to retrieve the set of all attributes for an element. There are methods on
the Element
interface to retrieve either an Attr
object by name or an attribute value by name. In XML, where an attribute
value may contain entity references, an Attr
object should be
retrieved to examine the possibly fairly complex sub-tree representing the
attribute value. On the other hand, in HTML, where all attributes have
simple string values, methods to directly access an attribute value can
safely be used as a convenience.
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(); // Introduced in DOM Level 2: DOMString getAttributeNS(in DOMString namespaceURI, in DOMString localName); // Introduced in DOM Level 2: void setAttributeNS(in DOMString namespaceURI, in DOMString localName, in DOMString value) raises(DOMException); // Introduced in DOM Level 2: void removeAttributeNS(in DOMString namespacURI, in DOMString localName) raises(DOMException); // Introduced in DOM Level 2: Attr getAttributeNodeNS(in DOMString namespaceURI, in DOMString localName); // Introduced in DOM Level 2: Attr setAttributeNodeNS(in Attr newAttr) raises(DOMException); // Introduced in DOM Level 2: NodeList getElementsByTagNameNS(in DOMString namespaceURI, in DOMString localName); };
tagName
of type DOMString
, readonly<elementExample id="demo"> ... </elementExample> ,
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.
getAttribute
setAttribute
Attr
node plus any Text
and
EntityReference
nodes, build the appropriate subtree, and
use setAttributeNode
to assign it as the value of an
attribute.
INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
removeAttribute
| The name of the attribute to remove. |
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
getAttributeNode
setAttributeNode
WRONG_DOCUMENT_ERR: Raised if NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. INUSE_ATTRIBUTE_ERR: Raised if |
removeAttributeNode
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if |
getElementsByTagName
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.
| The name of the tag to match on. The special value "*" matches all tags. |
A list of matching |
normalize
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.getAttributeNS
introduced in DOM Level 2
| The namespace URI of
the attribute to retrieve. When it is | |||
| The local name of the attribute to retrieve. |
setAttributeNS
introduced in DOM Level 2Attr
node plus any
Text
and EntityReference
nodes, build the
appropriate subtree, and use setAttributeNodeNS
or
setAttributeNode
to assign it as the value of an
attribute. HTML-only DOM implementations do not need to implement this
method.
| The namespace URI of
the attribute to create or alter. When it is | |||
| The local name of the attribute to create or alter. | |||
| The value to set in string form. |
INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character. NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
removeAttributeNS
introduced in DOM Level 2
| The namespace URI of
the attribute to remove. When it is | |||
| The local name of the attribute to remove. |
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
getAttributeNodeNS
introduced in DOM Level 2Attr
node by local name and namespace
URI. HTML-only DOM implementations do not need to implement this
method.
| The namespace URI of
the attribute to retrieve. When it is | |||
| The local name of the attribute to retrieve. |
setAttributeNodeNS
introduced in DOM Level 2
If the |
WRONG_DOCUMENT_ERR: Raised if NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. INUSE_ATTRIBUTE_ERR: Raised if |
getElementsByTagNameNS
introduced in DOM Level 2NodeList
of all the Element
s
with a given local name and namespace URI in the order in which they
would be encountered in a preorder traversal of the
Document
tree, starting from this node. HTML-only DOM
implementations do not need to implement this method.
| The namespace URI of
the elements to match on. The special value "*" matches all
namespaces. When it is | |||
| The local name of the elements to match on. The special value "*" matches all local names. |
The Text
interface inherits from
CharacterData
and 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.
interface Text : CharacterData { Text splitText(in unsigned long offset) raises(DOMException); };
splitText
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.
|
| The 16-bit unit offset at which to split, starting from 0. |
The new |
INDEX_SIZE_ERR: Raised if the specified offset is negative or
greater than the number of 16-bit units in NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. |
This interface inherits from CharacterData
and
represents the content of a comment, i.e., all the
characters between the starting '<!--
' and
ending '-->
'. Note that this is the definition
of a comment in XML, and, in practice, HTML, although some HTML
tools may implement the full SGML comment structure.
interface Comment : CharacterData { };
The interfaces defined here form part of the DOM 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.
A DOM application can use the hasFeature
method of the
DOMImplementation
interface to determine whether they
are supported or not. The feature string for all the interfaces listed in
this section is "XML".
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 from the
CharacterData
interface through the Text
interface. Adjacent CDATASections
nodes are not merged by
use of the normalize
method of the Element
interface.
interface CDATASection : Text { };
Each Document
has a doctype
attribute
whose value is either null
or a DocumentType
object. The DocumentType
interface in the DOM Core
provides an interface to the list of entities that are defined
for the document, and little else because the effect of
namespaces and the various XML scheme efforts on DTD
representation are not clearly understood as of this writing.
The DOM Level 2 doesn't support editing DocumentType
nodes.
interface DocumentType : Node { readonly attribute DOMString name; readonly attribute NamedNodeMap entities; readonly attribute NamedNodeMap notations; // Introduced in DOM Level 2: readonly attribute DOMString publicID; // Introduced in DOM Level 2: readonly attribute DOMString systemID; };
name
of type DOMString
, readonlyDOCTYPE
keyword.
entities
of type NamedNodeMap
, readonlyNamedNodeMap
containing the general entities, both
external and internal, declared in the DTD. Duplicates are discarded.
For example in:
<!DOCTYPE ex SYSTEM "ex.dtd" [ <!ENTITY foo "foo"> <!ENTITY bar "bar"> <!ENTITY % baz "baz"> ]> <ex/>
foo
and
bar
but not baz
. Every node in this map
also implements the Entity
interface.entities
cannot be altered in any way.
notations
of type NamedNodeMap
, readonlyNamedNodeMap
containing the
notations declared in the DTD. Duplicates are discarded. Every node in
this map also implements the Notation
interface.notations
cannot be altered in any way.
publicID
of type DOMString
, readonly, introduced in DOM Level 2
systemID
of type DOMString
, readonly, introduced in DOM Level 2
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.
interface Notation : Node { readonly attribute DOMString publicId; readonly attribute DOMString systemId; };
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 2 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.
interface Entity : Node { readonly attribute DOMString publicId; readonly attribute DOMString systemId; readonly attribute DOMString notationName; };
publicId
of type DOMString
, readonlynull
.
systemId
of type DOMString
, readonlynull
.
notationName
of type DOMString
, readonlynull
.
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.
interface EntityReference : Node { };
The ProcessingInstruction
interface
represents a "processing instruction", used in XML
as a way to keep processor-specific information in the text of the
document.
interface ProcessingInstruction : Node { readonly attribute DOMString target; attribute DOMString data; // raises(DOMException) on setting };
target
of type DOMString
, readonly
data
of type DOMString
?>
.
NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. |