Element (Org.W3C.DOM Package)

<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". The "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. .

See the following for methods.

getAttribute

Retrieves an attribute value by name.

Syntax:

public java.lang.String getAttribute(java.lang.String name)

Parameters:

name - The name of the attribute to retrieve.

Return value:

The Attr value as a string, or the empty string if that attribute does not have a specified or default value.

getAttributeNode

Retrieves an Attr node by name.

Syntax:

public Attr getAttributeNode(java.lang.String name)

Parameters:

name - The name of the attribute to retrieve.

Return value:

The Attr node with the specified attribute name or null if there is no such attribute.

getElementsByTagName

Returns a NodeList of all descendant elements with a given tag name, in the order in which they would be encountered during a preorder traversal of the Element tree.

Syntax:

public NodeList getElementsByTagName(java.lang.String name)

Parameters:

name - The name of the tag to match on. The special value "*" matches all tags.

Return value:

A list of matching Element nodes.

getTagName

The name of the element. For example, in: <elementExample id="demo"> ... </elementExample> , tagName has the value "elementExample". 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.

Syntax:

public java.lang.String getTagName()

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 reloaded, and is useful when operations (such as XPointer lookups) that depend on a particular document tree structure are to be used.

Syntax:

public void normalize()

removeAttribute

Removes an attribute by name. If the removed attribute has a default value it is immediately replaced.

Syntax:

public void removeAttribute(java.lang.String name)
             throws DOMException

Parameters:

name - The name of the attribute to remove.

Throws:

DOMException - NO_MODIFICATION_ALLOWED_ERR: Raised if this node is Read-only.

removeAttributeNode

Removes the specified attribute.

Syntax:

public Attr removeAttributeNode(Attr oldAttr)
           throws DOMException

Parameters:

oldAttr - The Attr node to remove from the attribute list. If the removed Attr has a default value it is immediately replaced.

Return value:

The Attr node that was removed.

Throws:

DOMException - NO_MODIFICATION_ALLOWED_ERR: Raised if this node is Read-only.

NOT_FOUND_ERR: Raised if oldAttr is not an attribute of the element.

setAttribute

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.

Syntax:

public void setAttribute(java.lang.String name, java.lang.String value)
              throws DOMException

Parameters:

name - The name of the attribute to create or alter.

value - Value to set in string form.

Throws:

DOMException - INVALID_CHARACTER_ERR: Raised if the specified name contains an invalid character.

NO_MODIFICATION_ALLOWED_ERR: Raised if this node is Read-only.

setAttributeNode

Adds a new attribute. If an attribute with that name is already present in the element, it is replaced by the new one.

Syntax:

public Attr setAttributeNode(Attr newAttr)
           throws DOMException

Parameters:

newAttr - The Attr node to add to the attribute list.

Return value:

If the newAttr attribute replaces an existing attribute with the same name, the previously existing 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.

NO_MODIFICATION_ALLOWED_ERR: Raised if this node is Read-only.

INUSE_ATTRIBUTE_ERR: Raised if newAttr is already an attribute of another Element object. The DOM user must explicitly clone Attr nodes to reuse them in other elements.