Chapter 3 DynaScript Predefined Objects

DOMNamedNodeMap object

Object

Represents a collection of DOMNode objects that can be accessed by name.

Syntax

To use a DOMNamedNodeMap's property:

DOMNamedNodeMap.propertyName

To use a DOMNamedNodeMap's method:

DOMNamedNodeMap.MethodName( parameter ) 

Description

DOMNamedNodeMap objects represent an unordered collection of DOMNode objects. Objects within the node map can be accessed by an ordinal index, but this is simply provided as a means of enumerating the objects within the node map. It does not imply that the objects within the node map are ordered.

length property

Syntax

DOMNamedNodeMap.length

Description

The number of objects in the map.

Example

This example loops over the items of a DOMNamedNodeMap object.

for ( i = 0; i < nodemap.length; i++ ){
  // operations here
}

See also

"DOMNamedNodeMap object"

getNamedItem method

Syntax

DOMNamedNodeMap.getNamedItem( name )

Description

Retrieves a DOMNode specified by name.

Return

A DOMNode object or null if the specified name did not identify any node in the map

Example

This example creates a DOMNamedNodeMap named attlist from the attributes property of an element, and then writes out the value of the attribute with name attName:

attlist = elem.attributes
att = attlist.getNamedItem( attName );
document.writeln( att.value );

See also

"DOMNode object"

item method

Syntax

DOMNamedNodeMap.item( index )

Description

Returns the index item in the map. If index is greater than or equal to the number of nodes in the map, null is returned. Valid values for index are 0 through length minus one.

Return

A DOMNode object or null if the index is invalid

Example

This script fragment loops over the items of a DOMNamedNodeMap object and assigns each node to a variable named thisNode:

for ( i = 0; i < nodemap.length; i++ ){
  thisNode = nodemap.item( i );
}

removeNamedItem method

Syntax

DOMNamedNodeMap.removeNamedItem( name )

Description

Removes a DOMNode object specified by name.

Return

The DOMNode object that was removed, or null if the specified name did not identify any node in the map

Example

This example removes the attribute named attType from each Region element, and prints out messages for debugging purposes:

function RemoveNamedItem( domDoc, attType ){
  elemlist = domDoc.getElementsByTagName( "Region" )
  for( iElem=0; iElem < elemlist.length; iElem++ ) {
    elem = elemlist.item( iElem );
    attlist = elem.attributes
    node = attlist.removeNamedItem( attType );
    if( node == null ) {
      document.writeln( "No attribute removed" );
    } else {
     document.writeln( "Removed attribute with value" 
+ node.nodeValue );
    }
  }
  document.writeln( domDoc.prettyPrint() );
}

See also

"DOMNode object"

setNamedItem method

Syntax

DOMNamedNodeMap.setNamedItem( node-name )

Description

Adds a node using its nodeName property. The node-name parameter is a DOMNode object to be stored in the named node map. The node will later be accessible using the value of the node's nodeName property passed to the getNamedItem method.

Return

If the new node replaces an existing node with the same name, the previously existing node is returned as a DOMNode object, otherwise null is returned.

Example

This example replaces an attribute node with one of the same name, but a changed value.

function SetNamedItem( domDoc, attType ){
  elemlist = domDoc.getElementsByTagName( "Region" )
  for( iElem=0; iElem < elemlist.length; iElem++ ) {
    elem = elemlist.item( iElem );
    attlist = elem.attributes
    att = attlist.getNamedItem( attType );
    att.value = "County";
    oldNode = attlist.setNamedItem( att.name );
    if( oldNode == null ) {
      document.writeln( "New attribute added" );
    } else {
      document.writeln( "Replaced attribute" );
    }
  }
}

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