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Common DOM API | |||||||||
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public interface Element
The Element
interface represents an element in an HTML or XML
document. Elements may have attributes associated with them; since the
Element
interface inherits from Node
, the
generic Node
interface attribute attributes
may
be used to retrieve the set of all attributes for an element. There are
methods on the Element
interface to retrieve either an
Attr
object by name or an attribute value by name. In XML,
where an attribute value may contain entity references, an
Attr
object should be retrieved to examine the possibly
fairly complex sub-tree representing the attribute value. On the other
hand, in HTML, where all attributes have simple string values, methods to
directly access an attribute value can safely be used as a convenience.
Note: In DOM Level 2, the method normalize
is
inherited from the Node
interface where it was moved.
See also the Document Object Model (DOM) Level 3 Core Specification.
Field Summary |
---|
Method Summary | |
---|---|
String |
getAttribute(String name)
Retrieves an attribute value by name. |
Attr |
getAttributeNode(String name)
Retrieves an attribute node by name. |
Attr |
getAttributeNodeNS(String namespaceURI,
String localName)
Retrieves an Attr node by local name and namespace URI. |
String |
getAttributeNS(String namespaceURI,
String localName)
Retrieves an attribute value by local name and namespace URI. |
NodeList |
getElementsByTagName(String name)
Returns a NodeList of all descendant Elements
with a given tag name, in document order. |
NodeList |
getElementsByTagNameNS(String namespaceURI,
String localName)
Returns a NodeList of all the descendant
Elements with a given local name and namespace URI in
document order. |
TypeInfo |
getSchemaTypeInfo()
The type information associated with this element. |
String |
getTagName()
The name of the element. |
boolean |
hasAttribute(String name)
Returns true when an attribute with a given name is
specified on this element or has a default value, false
otherwise. |
boolean |
hasAttributeNS(String namespaceURI,
String localName)
Returns true when an attribute with a given local name and
namespace URI is specified on this element or has a default value,
false otherwise. |
void |
removeAttribute(String name)
Removes an attribute by name. |
Attr |
removeAttributeNode(Attr oldAttr)
Removes the specified attribute node. |
void |
removeAttributeNS(String namespaceURI,
String localName)
Removes an attribute by local name and namespace URI. |
void |
setAttribute(String name,
String value)
Adds a new attribute. |
Attr |
setAttributeNode(Attr newAttr)
Adds a new attribute node. |
Attr |
setAttributeNodeNS(Attr newAttr)
Adds a new attribute. |
void |
setAttributeNS(String namespaceURI,
String qualifiedName,
String value)
Adds a new attribute. |
void |
setIdAttribute(String name,
boolean isId)
If the parameter isId is true , this method
declares the specified attribute to be a user-determined ID attribute
. |
void |
setIdAttributeNode(Attr idAttr,
boolean isId)
If the parameter isId is true , this method
declares the specified attribute to be a user-determined ID attribute
. |
void |
setIdAttributeNS(String namespaceURI,
String localName,
boolean isId)
If the parameter isId is true , this method
declares the specified attribute to be a user-determined ID attribute
. |
Methods inherited from interface org.w3c.dom.Node |
---|
appendChild, cloneNode, compareDocumentPosition, getAttributes, getBaseURI, getChildNodes, getFeature, getFirstChild, getLastChild, getLocalName, getNamespaceURI, getNextSibling, getNodeName, getNodeType, getNodeValue, getOwnerDocument, getParentNode, getPrefix, getPreviousSibling, getTextContent, getUserData, hasAttributes, hasChildNodes, insertBefore, isDefaultNamespace, isEqualNode, isSameNode, isSupported, lookupNamespaceURI, lookupPrefix, normalize, removeChild, replaceChild, setNodeValue, setPrefix, setTextContent, setUserData |
Method Detail |
---|
String getTagName()
Node.localName
is different
from null
, this attribute is a qualified name. For
example, in:
<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.
String getAttribute(String name)
name
- The name of the attribute to retrieve.
Attr
value as a string, or the empty string
if that attribute does not have a specified or default value.void setAttribute(String name, String value) throws DOMException
Attr
node plus any
Text
and EntityReference
nodes, build the
appropriate subtree, and use setAttributeNode
to assign
it as the value of an attribute.
setAttributeNS
method.
name
- The name of the attribute to create or alter.value
- Value to set in string form.
DOMException
- INVALID_CHARACTER_ERR: Raised if the specified name is not an XML
name according to the XML version in use specified in the
Document.xmlVersion
attribute.
void removeAttribute(String name) throws DOMException
Document.normalizeDocument()
to guarantee this
information is up-to-date.
removeAttributeNS
method.
name
- The name of the attribute to remove.
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.Attr getAttributeNode(String name)
getAttributeNodeNS
method.
name
- The name (nodeName
) of the attribute to
retrieve.
Attr
node with the specified name (
nodeName
) or null
if there is no such
attribute.Attr setAttributeNode(Attr newAttr) throws DOMException
nodeName
) is already present in the element, it is
replaced by the new one. Replacing an attribute node by itself has no
effect.
setAttributeNodeNS
method.
newAttr
- The Attr
node to add to the attribute list.
newAttr
attribute replaces an existing
attribute, the replaced Attr
node is returned,
otherwise null
is returned.
DOMException
- WRONG_DOCUMENT_ERR: Raised if newAttr
was created from a
different document than the one that created the element.
newAttr
is already an
attribute of another Element
object. The DOM user must
explicitly clone Attr
nodes to re-use them in other
elements.Attr removeAttributeNode(Attr oldAttr) throws DOMException
Attr
node is defined in the DTD, a new node
immediately appears with the default value as well as the
corresponding namespace URI, local name, and prefix when applicable.
The implementation may handle default values from other schemas
similarly but applications should use
Document.normalizeDocument()
to guarantee this
information is up-to-date.
oldAttr
- The Attr
node to remove from the attribute
list.
Attr
node that was removed.
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
oldAttr
is not an attribute
of the element.NodeList getElementsByTagName(String name)
NodeList
of all descendant Elements
with a given tag name, in document order.
name
- The name of the tag to match on. The special value "*"
matches all tags.
Element
nodes.String getAttributeNS(String namespaceURI, String localName) throws DOMException
null
as the
namespaceURI
parameter for methods if they wish to have
no namespace.
namespaceURI
- The namespace URI of the attribute to retrieve.localName
- The local name of the attribute to retrieve.
Attr
value as a string, or the empty string
if that attribute does not have a specified or default value.
DOMException
- NOT_SUPPORTED_ERR: May be raised if the implementation does not
support the feature "XML"
and the language exposed
through the Document does not support XML Namespaces (such as [HTML 4.01]).void setAttributeNS(String namespaceURI, String qualifiedName, String value) throws DOMException
qualifiedName
, and
its value is changed to be 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 setAttributeNodeNS
or
setAttributeNode
to assign it as the value of an
attribute.
null
as the
namespaceURI
parameter for methods if they wish to have
no namespace.
namespaceURI
- The namespace URI of the attribute to create or
alter.qualifiedName
- The qualified name of the attribute to create or
alter.value
- The value to set in string form.
DOMException
- INVALID_CHARACTER_ERR: Raised if the specified qualified name is not
an XML name according to the XML version in use specified in the
Document.xmlVersion
attribute.
qualifiedName
is
malformed per the Namespaces in XML specification, if the
qualifiedName
has a prefix and the
namespaceURI
is null
, if the
qualifiedName
has a prefix that is "xml" and the
namespaceURI
is different from "
http://www.w3.org/XML/1998/namespace", if the qualifiedName
or its prefix is "xmlns" and the
namespaceURI
is different from "http://www.w3.org/2000/xmlns/", or if the namespaceURI
is "http://www.w3.org/2000/xmlns/" and neither the qualifiedName
nor its prefix is "xmlns".
"XML"
and the language exposed
through the Document does not support XML Namespaces (such as [HTML 4.01]).void removeAttributeNS(String namespaceURI, String localName) throws DOMException
Document.normalizeDocument()
to guarantee this
information is up-to-date.
null
as the
namespaceURI
parameter for methods if they wish to have
no namespace.
namespaceURI
- The namespace URI of the attribute to remove.localName
- The local name of the attribute to remove.
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
"XML"
and the language exposed
through the Document does not support XML Namespaces (such as [HTML 4.01]).Attr getAttributeNodeNS(String namespaceURI, String localName) throws DOMException
Attr
node by local name and namespace URI.
null
as the
namespaceURI
parameter for methods if they wish to have
no namespace.
namespaceURI
- The namespace URI of the attribute to retrieve.localName
- The local name of the attribute to retrieve.
Attr
node with the specified attribute local
name and namespace URI or null
if there is no such
attribute.
DOMException
- NOT_SUPPORTED_ERR: May be raised if the implementation does not
support the feature "XML"
and the language exposed
through the Document does not support XML Namespaces (such as [HTML 4.01]).Attr setAttributeNodeNS(Attr newAttr) throws DOMException
null
as the
namespaceURI
parameter for methods if they wish to have
no namespace.
newAttr
- The Attr
node to add to the attribute list.
newAttr
attribute replaces an existing
attribute with the same local name and namespace URI, the replaced
Attr
node is returned, otherwise null
is
returned.
DOMException
- WRONG_DOCUMENT_ERR: Raised if newAttr
was created from a
different document than the one that created the element.
newAttr
is already an
attribute of another Element
object. The DOM user must
explicitly clone Attr
nodes to re-use them in other
elements.
"XML"
and the language exposed
through the Document does not support XML Namespaces (such as [HTML 4.01]).NodeList getElementsByTagNameNS(String namespaceURI, String localName) throws DOMException
NodeList
of all the descendant
Elements
with a given local name and namespace URI in
document order.
namespaceURI
- The namespace URI of the elements to match on. The
special value "*" matches all namespaces.localName
- The local name of the elements to match on. The
special value "*" matches all local names.
NodeList
object containing all the matched
Elements
.
DOMException
- NOT_SUPPORTED_ERR: May be raised if the implementation does not
support the feature "XML"
and the language exposed
through the Document does not support XML Namespaces (such as [HTML 4.01]).boolean hasAttribute(String name)
true
when an attribute with a given name is
specified on this element or has a default value, false
otherwise.
name
- The name of the attribute to look for.
true
if an attribute with the given name is
specified on this element or has a default value, false
otherwise.boolean hasAttributeNS(String namespaceURI, String localName) throws DOMException
true
when an attribute with a given local name and
namespace URI is specified on this element or has a default value,
false
otherwise.
null
as the
namespaceURI
parameter for methods if they wish to have
no namespace.
namespaceURI
- The namespace URI of the attribute to look for.localName
- The local name of the attribute to look for.
true
if an attribute with the given local name
and namespace URI is specified or has a default value on this
element, false
otherwise.
DOMException
- NOT_SUPPORTED_ERR: May be raised if the implementation does not
support the feature "XML"
and the language exposed
through the Document does not support XML Namespaces (such as [HTML 4.01]).TypeInfo getSchemaTypeInfo()
void setIdAttribute(String name, boolean isId) throws DOMException
isId
is true
, this method
declares the specified attribute to be a user-determined ID attribute
. This affects the value of Attr.isId
and the behavior
of Document.getElementById
, but does not change any
schema that may be in use, in particular this does not affect the
Attr.schemaTypeInfo
of the specified Attr
node. Use the value false
for the parameter
isId
to undeclare an attribute for being a
user-determined ID attribute.
setIdAttributeNS
method.
name
- The name of the attribute.isId
- Whether the attribute is a of type ID.
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
void setIdAttributeNS(String namespaceURI, String localName, boolean isId) throws DOMException
isId
is true
, this method
declares the specified attribute to be a user-determined ID attribute
. This affects the value of Attr.isId
and the behavior
of Document.getElementById
, but does not change any
schema that may be in use, in particular this does not affect the
Attr.schemaTypeInfo
of the specified Attr
node. Use the value false
for the parameter
isId
to undeclare an attribute for being a
user-determined ID attribute.
namespaceURI
- The namespace URI of the attribute.localName
- The local name of the attribute.isId
- Whether the attribute is a of type ID.
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
void setIdAttributeNode(Attr idAttr, boolean isId) throws DOMException
isId
is true
, this method
declares the specified attribute to be a user-determined ID attribute
. This affects the value of Attr.isId
and the behavior
of Document.getElementById
, but does not change any
schema that may be in use, in particular this does not affect the
Attr.schemaTypeInfo
of the specified Attr
node. Use the value false
for the parameter
isId
to undeclare an attribute for being a
user-determined ID attribute.
idAttr
- The attribute node.isId
- Whether the attribute is a of type ID.
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
|
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