org.w3c.dom
Interface Element
java.lang.Object
|
+--org.w3c.dom.Node
|
+--org.w3c.dom.Element
All Implemented Interfaces:
Node
public interface
Elementimplements
Node 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.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 2 Core Specification.
getAttribute
public String getAttribute(java.lang.String name)
Retrieves an attribute value by name.
Parameters:
Returns:
- The
Attr
value as a string, or the empty string
if that attribute does not have a specified or default value.
getAttributeNS
public String getAttributeNS(java.lang.String namespaceURI, java.lang.String localName)
Retrieves an attribute value by local name and namespace URI.
Documents which do not support the "XML" feature will permit only
the DOM Level 1 calls for creating/setting elements and attributes.
Hence, if you specify a non-null namespace URI, these DOMs will never
find a matching node.
Since:Parameters:
Returns:
- The
Attr
value as a string, or the empty string
if that attribute does not have a specified or default value.
getAttributeNode
public Attr getAttributeNode(java.lang.String name)
Retrieves an attribute node by name.
To retrieve an attribute node by qualified name and namespace URI,
use the getAttributeNodeNS
method.
Parameters:
Returns:
- The
Attr
node with the specified name (
nodeName
) or null
if there is no such
attribute.
getAttributeNodeNS
public Attr getAttributeNodeNS(java.lang.String namespaceURI, java.lang.String localName)
Retrieves an Attr
node by local name and namespace URI.
Documents which do not support the "XML" feature will permit only
the DOM Level 1 calls for creating/setting elements and attributes.
Hence, if you specify a non-null namespace URI, these DOMs will never
find a matching node.
Since:Parameters:
Returns:
- The
Attr
node with the specified attribute local
name and namespace URI or null
if there is no such
attribute.
getElementsByTagName
public NodeList getElementsByTagName(java.lang.String name)
Returns a NodeList
of all descendant Elements
with a given tag name, in the order in which they are encountered in
a preorder traversal of this Element
tree.
Parameters:
Returns:
- A list of matching
Element
nodes.
getElementsByTagNameNS
public NodeList getElementsByTagNameNS(java.lang.String namespaceURI, java.lang.String localName)
Returns a NodeList
of all the descendant
Elements
with a given local name and namespace URI in
the order in which they are encountered in a preorder traversal of
this Element
tree.
Documents which do not support the "XML" feature will permit only
the DOM Level 1 calls for creating/setting elements and attributes.
Hence, if you specify a non-null namespace URI, these DOMs will never
find a matching node.
Since:Parameters:
Returns:
- A new
NodeList
object containing all the matched
Elements
.
getTagName
public String getTagName()
The name of the element. 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.
hasAttribute
public boolean hasAttribute(java.lang.String name)
Returns true
when an attribute with a given name is
specified on this element or has a default value, false
otherwise.
Since:Parameters:
Returns:
true
if an attribute with the given name is
specified on this element or has a default value, false
otherwise.
hasAttributeNS
public boolean hasAttributeNS(java.lang.String namespaceURI, java.lang.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.
Documents which do not support the "XML" feature will permit only
the DOM Level 1 calls for creating/setting elements and attributes.
Hence, if you specify a non-null namespace URI, these DOMs will never
find a matching node.
Since:Parameters:
Returns:
true
if an attribute with the given local name
and namespace URI is specified or has a default value on this
element, false
otherwise.
removeAttribute
public void removeAttribute(java.lang.String name)
Removes an attribute by name. If the removed attribute is known to have
a default value, an attribute immediately appears containing the
default value as well as the corresponding namespace URI, local name,
and prefix when applicable.
To remove an attribute by local name and namespace URI, use the
removeAttributeNS
method.
Parameters:
Throws:
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
removeAttributeNS
public void removeAttributeNS(java.lang.String namespaceURI, java.lang.String localName)
Removes an attribute by local name and namespace URI. If the removed
attribute has a default value it is immediately replaced. The
replacing attribute has the same namespace URI and local name, as
well as the original prefix.
Documents which do not support the "XML" feature will permit only
the DOM Level 1 calls for creating/setting elements and attributes.
Hence, if you specify a non-null namespace URI, these DOMs will never
find a matching node.
Since:Parameters:
Throws:
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
removeAttributeNode
public Attr removeAttributeNode(org.w3c.dom.Attr oldAttr)
Removes the specified attribute node. If the removed Attr
has a default value it is immediately replaced. The replacing
attribute has the same namespace URI and local name, as well as the
original prefix, when applicable.
Parameters:
Returns:
- The
Attr
node that was removed.
Throws:
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
setAttribute
public void setAttribute(java.lang.String name, java.lang.String value)
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.
To set an attribute with a qualified name and namespace URI, use
the setAttributeNS
method.
Parameters:
Throws:
DOMException
- INVALID_CHARACTER_ERR: Raised if the specified name contains an
illegal character.
setAttributeNS
public void setAttributeNS(java.lang.String namespaceURI, java.lang.String qualifiedName, java.lang.String value)
Adds a new attribute. If an attribute with the same local name and
namespace URI is already present on the element, its prefix is
changed to be the prefix part of the 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.
Since:Parameters:
Throws:
DOMException
- INVALID_CHARACTER_ERR: Raised if the specified qualified name
contains an illegal character, per the XML 1.0 specification .
setAttributeNode
public Attr setAttributeNode(org.w3c.dom.Attr newAttr)
Adds a new attribute node. If an attribute with that name (
nodeName
) is already present in the element, it is
replaced by the new one.
To add a new attribute node with a qualified name and namespace
URI, use the setAttributeNodeNS
method.
Parameters:
Returns:
- If the
newAttr
attribute replaces an existing
attribute, the replaced Attr
node is returned,
otherwise null
is returned.
Throws:
DOMException
- WRONG_DOCUMENT_ERR: Raised if newAttr
was created from a
different document than the one that created the element.
setAttributeNodeNS
public Attr setAttributeNodeNS(org.w3c.dom.Attr newAttr)
Adds a new attribute. If an attribute with that local name and that
namespace URI is already present in the element, it is replaced by
the new one.
Since:Parameters:
Returns:
- If the
newAttr
attribute replaces an existing
attribute with the same local name and namespace URI, the replaced
Attr
node is returned, otherwise null
is
returned.
Throws:
DOMException
- WRONG_DOCUMENT_ERR: Raised if newAttr
was created from a
different document than the one that created the element.
Element
interface represents an element in an HTML or XML document. Elements may have attributes associated with them; since theElement
interface inherits fromNode
, the genericNode
interface attributeattributes
may be used to retrieve the set of all attributes for an element. There are methods on theElement
interface to retrieve either anAttr
object by name or an attribute value by name. In XML, where an attribute value may contain entity references, anAttr
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.In DOM Level 2, the methodnormalize
is inherited from theNode
interface where it was moved.See also the Document Object Model (DOM) Level 2 Core Specification.