org.w3c.dom.Element Maven / Gradle / Ivy
// Copyright (c) 1998 by W3C
//
// DOM is a trademark of W3C
// The DOM level 1 specification, from which this
// source is derived, is copyright by W3C.
// See: http://www.w3.org/TR/REC-DOM-Level-1/
//
package org.w3c.dom;
/**
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:
<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.
*/
public interface Element
extends Node
{
/**
* Returns the value of the tagName property.
*/
String getTagName ();
/**
Retrieves an attribute value by name.
@return The Attr value as a string, or the empty
string if that attribute does not have a specified or default value.
@param name
The name of the attribute to retrieve.
*/
String getAttribute (String name);
/**
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.
@param name
The name of the attribute to create or alter.
@param value
Value to set in string form.
@exception INVALID_CHARACTER_ERR: Raised if the specified name contains
an invalid character.
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
*/
void setAttribute (String name, String value) throws DOMException;
/**
Removes an attribute by name. If the removed attribute
has a default value it is immediately replaced.
@param name
The name of the attribute to remove.
@exception NO_MODIFICATION_ALLOWED_ERR: Raised if this node is
readonly.
*/
void removeAttribute (String name) throws DOMException;
/**
Retrieves an Attr node by name.
@return The Attr node with the specified attribute
name or null if there is no such attribute.
@param name
The name of the attribute to retrieve.
*/
Attr getAttributeNode (String name);
/**
Adds a new attribute. If an attribute with that
name is already present in the element, it is replaced
by the new one.
@return If the newAttr attribute replaces
an existing attribute with the same name, the
previously existing Attr node is returned, otherwise
null is returned.
@param newAttr
The Attr node to add to the attribute
list.
@exception WRONG_DOCUMENT_ERR: Raised if 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.
*/
Attr setAttributeNode (Attr newAttr) throws DOMException;
/**
Removes the specified attribute.
@return The Attr node that was removed.
@param oldAttr
The Attr node to remove from the attribute
list. If the removed Attr has a default value it is
immediately replaced.
@exception NO_MODIFICATION_ALLOWED_ERR: Raised if this node is
readonly.
NOT_FOUND_ERR: Raised if oldAttr is not an attribute of
the element.
*/
Attr removeAttributeNode (Attr oldAttr) throws DOMException;
/**
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.
@return A list of matching Element nodes.
@param name
The name of the tag to match on. The special value "*"
matches all tags.
*/
NodeList getElementsByTagName (String name);
/**
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.
*/
void normalize ();
}