# 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](http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407). ### Public Method Summary |---|---| | abstract int | [getLength](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/NamedNodeMap.html#getLength())() The number of nodes in this map. | | abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) | [getNamedItem](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/NamedNodeMap.html#getNamedItem(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) name) Retrieves a node specified by name. | | abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) | [getNamedItemNS](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/NamedNodeMap.html#getNamedItemNS(java.lang.String,%20java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) namespaceURI, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) localName) Retrieves a node specified by local name and namespace URI. | | abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) | [item](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/NamedNodeMap.html#item(int))(int index) Returns the `index`th item in the map. | | abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) | [removeNamedItem](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/NamedNodeMap.html#removeNamedItem(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) name) Removes a node specified by name. | | abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) | [removeNamedItemNS](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/NamedNodeMap.html#removeNamedItemNS(java.lang.String,%20java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) namespaceURI, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) localName) Removes a node specified by local name and namespace URI. | | abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) | [setNamedItem](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/NamedNodeMap.html#setNamedItem(org.w3c.dom.Node))([Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) arg) Adds a node using its `nodeName` attribute. | | abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) | [setNamedItemNS](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/NamedNodeMap.html#setNamedItemNS(org.w3c.dom.Node))([Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) arg) Adds a node using its `namespaceURI` and `localName`. | ## Public Methods #### public abstract int **getLength** () The number of nodes in this map. The range of valid child node indices is `0` to `length-1` inclusive. #### public abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) **getNamedItem** ([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) name) Retrieves a node specified by name. ##### Parameters | name | The `nodeName` of a node to retrieve. | |---|---| ##### Returns - A `Node` (of any type) with the specified `nodeName`, or `null` if it does not identify any node in this map. #### public abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) **getNamedItemNS** ([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) namespaceURI, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) localName) Retrieves a node specified by local name and namespace URI. Per \[[XML Namespaces](http://www.w3.org/TR/1999/REC-xml-names-19990114/)\] , 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, or `null` if they do not identify any node in this map. ##### Throws | [DOMException](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/DOMException.html) | 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 \[[HTML 4.01](http://www.w3.org/TR/1999/REC-html401-19991224/)\]). | |---|---| #### public abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) **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, or `null` if that is not a valid index. #### public abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) **removeNamedItem** ([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) name) 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 | The `nodeName` of the node to remove. | |---|---| ##### Returns - The node removed from this map if a node with such a name exists. ##### Throws | [DOMException](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/DOMException.html) | NOT_FOUND_ERR: Raised if there is no node named `name` in this map. NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly. | |---|---| #### public abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) **removeNamedItemNS** ([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) namespaceURI, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) localName) 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 \[[XML Namespaces](http://www.w3.org/TR/1999/REC-xml-names-19990114/)\] , 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](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/DOMException.html) | NOT_FOUND_ERR: Raised if there is no node with the specified `namespaceURI` and `localName` 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 \[[HTML 4.01](http://www.w3.org/TR/1999/REC-html401-19991224/)\]). | |---|---| #### public abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) **setNamedItem** ([Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) arg) 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 its `nodeName` attribute. | |---|---| ##### Returns - If the new `Node` replaces an existing node the replaced `Node` is returned, otherwise `null` is returned. ##### Throws | [DOMException](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/DOMException.html) | WRONG_DOCUMENT_ERR: Raised if `arg` 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 if `arg` is an `Attr` that is already an attribute of another `Element` object. The DOM user must explicitly clone `Attr` 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. | |---|---| #### public abstract [Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) **setNamedItemNS** ([Node](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/Node.html) arg) 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 \[[XML Namespaces](http://www.w3.org/TR/1999/REC-xml-names-19990114/)\] , 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 its `namespaceURI` and `localName` attributes. | |---|---| ##### Returns - If the new `Node` replaces an existing node the replaced `Node` is returned, otherwise `null` is returned. ##### Throws | [DOMException](https://developers.google.com/j2objc/javadoc/jre/reference/org/w3c/dom/DOMException.html) | WRONG_DOCUMENT_ERR: Raised if `arg` 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 if `arg` is an `Attr` that is already an attribute of another `Element` object. The DOM user must explicitly clone `Attr` 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 \[[HTML 4.01](http://www.w3.org/TR/1999/REC-html401-19991224/)\]). | |---|---|