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SUMMARY: INNER | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
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 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.
Fields inherited from class org.w3c.dom.Node |
ATTRIBUTE_NODE,
CDATA_SECTION_NODE,
COMMENT_NODE,
DOCUMENT_FRAGMENT_NODE,
DOCUMENT_NODE,
DOCUMENT_TYPE_NODE,
ELEMENT_NODE,
ENTITY_NODE,
ENTITY_REFERENCE_NODE,
NOTATION_NODE,
PROCESSING_INSTRUCTION_NODE,
TEXT_NODE |
Method Summary | |
java.lang.String |
getAttribute(java.lang.String name)
Retrieves an attribute value by name. |
org.w3c.dom.Attr |
getAttributeNode(java.lang.String name)
Retrieves an Attr node by name. |
org.w3c.dom.NodeList |
getElementsByTagName(java.lang.String name)
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. |
java.lang.String |
getTagName()
The name of the element. |
void |
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. |
void |
removeAttribute(java.lang.String name)
Removes an attribute by name. |
org.w3c.dom.Attr |
removeAttributeNode(org.w3c.dom.Attr oldAttr)
Removes the specified attribute. |
void |
setAttribute(java.lang.String name,
java.lang.String value)
Adds a new attribute. |
org.w3c.dom.Attr |
setAttributeNode(org.w3c.dom.Attr newAttr)
Adds a new attribute. |
Methods inherited from interface org.w3c.dom.Node |
appendChild,
cloneNode,
getAttributes,
getChildNodes,
getFirstChild,
getLastChild,
getNextSibling,
getNodeName,
getNodeType,
getNodeValue,
getOwnerDocument,
getParentNode,
getPreviousSibling,
hasChildNodes,
insertBefore,
removeChild,
replaceChild,
setNodeValue |
Method Detail |
public java.lang.String getTagName()
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.public java.lang.String getAttribute(java.lang.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.public void setAttribute(java.lang.String name, java.lang.String value) throws org.w3c.dom.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.name
- The name of the attribute to create or alter.value
- Value to set in string form.public void removeAttribute(java.lang.String name) throws org.w3c.dom.DOMException
name
- The name of the attribute to remove.public org.w3c.dom.Attr getAttributeNode(java.lang.String name)
Attr
node by name.name
- The name of the attribute to retrieve.Attr
node with the specified attribute name or
null
if there is no such attribute.public org.w3c.dom.Attr setAttributeNode(org.w3c.dom.Attr newAttr) throws org.w3c.dom.DOMException
newAttr
- The Attr
node to add to the attribute list.newAttr
attribute replaces an existing
attribute with the same name, the previously existing
Attr
node is returned, otherwise null
is
returned.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.public org.w3c.dom.Attr removeAttributeNode(org.w3c.dom.Attr oldAttr) throws org.w3c.dom.DOMException
oldAttr
- The Attr
node to remove from the attribute
list. If the removed Attr
has a default value it is
immediately replaced.Attr
node that was removed.oldAttr
is not an attribute
of the element.public org.w3c.dom.NodeList getElementsByTagName(java.lang.String name)
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.name
- The name of the tag to match on. The special value "*"
matches all tags.Element
nodes.public void 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.
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