org.jaxen.function

Class IdFunction

public class IdFunction extends Object implements Function

4.1 node-set id(object)

The id function returns a List of all the elements in the context document that have an ID matching one of a specified list of IDs. How an attribute is determined to be of type ID depends on the navigator, but it normally requires that the attribute be declared to have type ID in the DTD.

There should be no more than one element in any document with a certain ID. However, if there are multiple such elements--i.e. if there are duplicate IDs--then this function selects only the first element in document order with the specified ID.

Author: Erwin Bolwidt (ejb @ klomp.org) Jérôme Nègre (jerome.negre @ e-xmlmedia.fr)

See Also: Section 4.1 of the XPath Specification

Constructor Summary
IdFunction()
Create a new IdFunction object.
Method Summary
Objectcall(Context context, List args)
Returns a list of the nodes with the specified IDs.
static Listevaluate(List contextNodes, Object arg, Navigator nav)
Returns a list of the nodes with the specified IDs.

Constructor Detail

IdFunction

public IdFunction()
Create a new IdFunction object.

Method Detail

call

public Object call(Context context, List args)
Returns a list of the nodes with the specified IDs.

Parameters: context the context at the point in the expression when the function is called args a list with exactly one item which is either a string a node-set

Returns: a List containing the first node in document with each of the specified IDs; or an empty list if there are no such nodes

Throws: FunctionCallException if args has more or less than one item

evaluate

public static List evaluate(List contextNodes, Object arg, Navigator nav)
Returns a list of the nodes with the specified IDs.

Parameters: contextNodes the context node-set. The first item in this list determines the document in which the search is performed. arg the ID or IDs to search for nav the navigator used to calculate string-values and search by ID

Returns: a List containing the first node in document with each of the specified IDs; or an empty list if there are no such nodes