NamedNodeMap (W3C DOM Core object)
| Version | Depr. |
|---|---|
| DOM1 | No |
| IE5.5+ | FF1.5+ | SA1.3+ | OP9+ |
|---|---|---|---|
| Buggy | Buggy | Buggy | Buggy |
Example
var collection = node.attributes;
The example above creates a reference to the attributes collection of a Node. If
there were an attribute in that collection called
darth, it could be accessed as
collection['darth'] or
collection.getNamedItem('darth').
If we knew it
was, say, the first item in the collection, it could also be accessed as
collection[0]; but since a
NamedNodeMap is not in any particular order, we
generally won't know our item's index. The ability to access the members
by index is designed to make it easy to iterate through a collection:
for(var i=0; i<collection.length; i++)
{
doSomethingWith(collection[i]);
}Description
The
NamedNodeMap interface represents an
unordered collection of items (such as nodes, or string values),
indexed by name.
It's also possible to access the items in a
NamedNodeMap by number (starting from zero), however
the DOM does not specify their order.
A named node map is a live collection, which means that changes to the collection it represents are immediately reflected in the node map (as opposed to it being a static snapshot).
The nodeName is used as the name under which a node is
stored in a node map, which implies that for certain kinds of node — where
all instances have the same name (such as #text or
#comment) — it's not possible to store more than one
instance of such a node within a single node map, because the names would
clash. The DOM specification considers this preferable to implementing
aliases.
Even though a node map looks like an array, it isn't an array —
although you can iterate through it and refer to its members like an
array, you can't use Array methods like
push or pop on it.
Compatibility
| Internet Explorer | Firefox | Safari | Opera | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 5.5 | 6.0 | 7.0 | 1.5 | 2.0 | 3.0 | 1.3 | 2.0 | 3.0 | 9.0 | 9.5 |
| Buggy | Buggy | Buggy | Buggy | Buggy | Buggy | Buggy | Buggy | Buggy | Buggy | Buggy |
Internet Explorer doesn't implement the following:
Additionally, Internet Explorer 5.5 in HTML doesn't implement the following (but does in XML):
Internet Explorer has a buggy
implementation of setNamedItem.
In
all versions of Internet Explorer in HTML, the
item method identifies as being of type
string, rather than function; however it
still works correctly.
Firefox,
Safari 1.3 and 2 and
Opera have buggy implementations of getNamedItemNS and removeNamedItemNS.
All
browsers have buggy implementations of removeNamedItem and setNamedItemNS (where they’re supported at
all).
In this Section
- getNamedItem
Get a node with the specified name from a named node map. - getNamedItemNS
Get a node with the specified local name and namespace URI from a named node map. - item
Get a node with the specified index from a node list or named node map. - length
The number of items in a named node map. - removeNamedItem
Remove a node with the specified name from a named node map. - removeNamedItemNS
Remove a node with the specified name and namespace URI from a named node map. - setNamedItem
Add a specified node to a named node map. - setNamedItemNS
Add a specified namespaced node to a named node map.
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