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Interface org.w3c.dom.Element

public interface Element

extends Node

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.

getAttribute(String)

Retrieves an attribute value by name.

getAttributeNode(String)

Retrieves an Attr node by name.

getElementsByTagName(String)

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.

getTagName()

The name of the element.

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.

removeAttribute(String)

Removes an attribute by name.

removeAttributeNode(Attr)

Removes the specified attribute.

setAttribute(String, String)

Adds a new attribute.

setAttributeNode(Attr)

Adds a new attribute.

 public abstract 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.

 public abstract String getAttribute(String name)

Retrieves an attribute value by name.

Parameters:

name - The name of the attribute to retrieve.

Returns:

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

 public abstract void setAttribute(String name,
                                   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.

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 readonly.

 public abstract void removeAttribute(String name) throws DOMException

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

Parameters:

name - The name of the attribute to remove.

Throws: DOMException

NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

 public abstract Attr getAttributeNode(String name)

Retrieves an Attr node by name.

Parameters:

name - The name of the attribute to retrieve.

Returns:

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

 public abstract 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.

Parameters:

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

Returns:

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 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 abstract Attr removeAttributeNode(Attr oldAttr) throws DOMException

Removes the specified attribute.

Parameters:

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

Returns:

The Attr node that was removed.

Throws: DOMException

NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
NOT_FOUND_ERR: Raised if oldAttr is not an attribute of the element.

 public abstract NodeList getElementsByTagName(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.

Parameters:

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

Returns:

A list of matching Element nodes.

 public abstract 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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