Interface NamedNodeMap
public interface NamedNodeMap
Objects implementing the NamedNodeMap
interface are used to represent collections of nodes that can be accessed by name. Note that NamedNodeMap
does not inherit from NodeList
; NamedNodeMaps
are not maintained in any particular order. Objects contained in an object implementing NamedNodeMap
may also be accessed by an ordinal index, but this is simply to allow convenient enumeration of the contents of a NamedNodeMap
, and does not imply that the DOM specifies an order to these Nodes.
NamedNodeMap
objects in the DOM are live.
See also the Document Object Model (DOM) Level 3 Core Specification.
Method Summary
Modifier and Type | Method | Description |
---|---|---|
int | getLength() | The number of nodes in this map. |
Node | getNamedItem(String name) | Retrieves a node specified by name. |
Node | getNamedItemNS(String namespaceURI,
String localName) | Retrieves a node specified by local name and namespace URI. |
Node | item(int index) | Returns the |
Node | removeNamedItem(String name) | Removes a node specified by name. |
Node | removeNamedItemNS(String namespaceURI,
String localName) | Removes a node specified by local name and namespace URI. |
Node | setNamedItem(Node arg) | Adds a node using its |
Node | setNamedItemNS(Node arg) | Adds a node using its |
Method Detail
getNamedItem
Node getNamedItem(String name)
Retrieves a node specified by name.
- Parameters:
-
name
- ThenodeName
of a node to retrieve. - Returns:
- A
Node
(of any type) with the specifiednodeName
, ornull
if it does not identify any node in this map.
setNamedItem
Node setNamedItem(Node arg) throws DOMException
Adds a node using its nodeName
attribute. If a node with that name is already present in this map, it is replaced by the new one. Replacing a node by itself has no effect.
As the nodeName
attribute is used to derive the name which the node must be stored under, multiple nodes of certain types (those that have a "special" string value) cannot be stored as the names would clash. This is seen as preferable to allowing nodes to be aliased.
- Parameters:
-
arg
- A node to store in this map. The node will later be accessible using the value of itsnodeName
attribute. - Returns:
- If the new
Node
replaces an existing node the replacedNode
is returned, otherwisenull
is returned. - Throws:
-
DOMException
- WRONG_DOCUMENT_ERR: Raised ifarg
was created from a different document than the one that created this map.
NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
INUSE_ATTRIBUTE_ERR: Raised ifarg
is anAttr
that is already an attribute of anotherElement
object. The DOM user must explicitly cloneAttr
nodes to re-use them in other elements.
HIERARCHY_REQUEST_ERR: Raised if an attempt is made to add a node doesn't belong in this NamedNodeMap. Examples would include trying to insert something other than an Attr node into an Element's map of attributes, or a non-Entity node into the DocumentType's map of Entities.
removeNamedItem
Node removeNamedItem(String name) throws DOMException
Removes a node specified by name. When this map contains the attributes attached to an element, if the removed attribute is known to have a default value, an attribute immediately appears containing the default value as well as the corresponding namespace URI, local name, and prefix when applicable.
- Parameters:
-
name
- ThenodeName
of the node to remove. - Returns:
- The node removed from this map if a node with such a name exists.
- Throws:
-
DOMException
- NOT_FOUND_ERR: Raised if there is no node namedname
in this map.
NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
item
Node item(int index)
Returns the index
th item in the map. If index
is greater than or equal to the number of nodes in this map, this returns null
.
- Parameters:
-
index
- Index into this map. - Returns:
- The node at the
index
th position in the map, ornull
if that is not a valid index.
getLength
int getLength()
The number of nodes in this map. The range of valid child node indices is 0
to length-1
inclusive.
getNamedItemNS
Node getNamedItemNS(String namespaceURI, String localName) throws DOMException
Retrieves a node specified by local name and namespace URI.
Per [XML Namespaces] , applications must use the value null as the namespaceURI parameter for methods if they wish to have no namespace.
- Parameters:
-
namespaceURI
- The namespace URI of the node to retrieve. -
localName
- The local name of the node to retrieve. - Returns:
- A
Node
(of any type) with the specified local name and namespace URI, ornull
if they do not identify any node in this map. - Throws:
-
DOMException
- NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature "XML" and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]). - Since:
- 1.4, DOM Level 2
setNamedItemNS
Node setNamedItemNS(Node arg) throws DOMException
Adds a node using its namespaceURI
and localName
. If a node with that namespace URI and that local name is already present in this map, it is replaced by the new one. Replacing a node by itself has no effect.
Per [XML Namespaces] , applications must use the value null as the namespaceURI parameter for methods if they wish to have no namespace.
- Parameters:
-
arg
- A node to store in this map. The node will later be accessible using the value of itsnamespaceURI
andlocalName
attributes. - Returns:
- If the new
Node
replaces an existing node the replacedNode
is returned, otherwisenull
is returned. - Throws:
-
DOMException
- WRONG_DOCUMENT_ERR: Raised ifarg
was created from a different document than the one that created this map.
NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
INUSE_ATTRIBUTE_ERR: Raised ifarg
is anAttr
that is already an attribute of anotherElement
object. The DOM user must explicitly cloneAttr
nodes to re-use them in other elements.
HIERARCHY_REQUEST_ERR: Raised if an attempt is made to add a node doesn't belong in this NamedNodeMap. Examples would include trying to insert something other than an Attr node into an Element's map of attributes, or a non-Entity node into the DocumentType's map of Entities.
NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature "XML" and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]). - Since:
- 1.4, DOM Level 2
removeNamedItemNS
Node removeNamedItemNS(String namespaceURI, String localName) throws DOMException
Removes a node specified by local name and namespace URI. A removed attribute may be known to have a default value when this map contains the attributes attached to an element, as returned by the attributes attribute of the Node
interface. If so, an attribute immediately appears containing the default value as well as the corresponding namespace URI, local name, and prefix when applicable.
Per [XML Namespaces] , applications must use the value null as the namespaceURI parameter for methods if they wish to have no namespace.
- Parameters:
-
namespaceURI
- The namespace URI of the node to remove. -
localName
- The local name of the node to remove. - Returns:
- The node removed from this map if a node with such a local name and namespace URI exists.
- Throws:
-
DOMException
- NOT_FOUND_ERR: Raised if there is no node with the specifiednamespaceURI
andlocalName
in this map.
NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature "XML" and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]). - Since:
- 1.4, DOM Level 2