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.
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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 theindex
th item in the map.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 itsnodeName
attribute.Node
setNamedItemNS(Node arg)
Adds a node using itsnamespaceURI
andlocalName
.
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Method Details
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getNamedItem
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.
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setNamedItem
Adds a node using itsnodeName
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 thenodeName
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.
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removeNamedItem
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.
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item
Returns theindex
th item in the map. Ifindex
is greater than or equal to the number of nodes in this map, this returnsnull
.- 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.
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getLength
int getLength()The number of nodes in this map. The range of valid child node indices is0
tolength-1
inclusive. -
getNamedItemNS
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
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setNamedItemNS
Adds a node using itsnamespaceURI
andlocalName
. 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
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removeNamedItemNS
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 theNode
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
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