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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.
| Property Summary | ||
tagName |
getTagName | The name of the element. For example, in:
|
| Fields inherited from interface 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. |
Attr |
getAttributeNode(java.lang.String name)
Retrieves an Attr node by name. |
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()
Returns the value of the tagName property. |
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. |
Attr |
removeAttributeNode(Attr oldAttr)
Removes the specified attribute. |
void |
setAttribute(java.lang.String name,
java.lang.String value)
Adds a new attribute. |
Attr |
setAttributeNode(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 property.public java.lang.String getAttribute(java.lang.String name)
Retrieves an attribute value by 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 DOMException
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.
name - The name of the attribute to create or alter.value - Value to set in string form.NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
public void removeAttribute(java.lang.String name)
throws DOMException
Removes an attribute by name. If the removed attribute has a default value it is immediately replaced.
name - The name of the attribute to remove.public Attr getAttributeNode(java.lang.String name)
Retrieves an 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 Attr setAttributeNode(Attr newAttr)
throws DOMException
Adds a new attribute. If an attribute with that name is already present in the element, it is replaced by the new one.
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.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.
public Attr removeAttributeNode(Attr oldAttr)
throws DOMException
Removes the specified attribute.
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.NOT_FOUND_ERR: Raised if oldAttr is not an attribute of
the element.
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 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()
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.
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