net.sf.saxon.xpath

Class XPathFunctionLibrary

Implemented Interfaces:
FunctionLibrary, Serializable

public class XPathFunctionLibrary
extends java.lang.Object
implements FunctionLibrary

The XPathFunctionLibrary is a FunctionLibrary that supports binding of XPath function calls to instances of the JAXP XPathFunction interface returned by an XPathFunctionResolver.

Constructor Summary

XPathFunctionLibrary()
Construct a XPathFunctionLibrary

Method Summary

Expression
bind(StructuredQName functionName, Expression[] staticArgs, StaticContext env)
Bind a function, given the URI and local parts of the function name, and the list of expressions supplied as arguments.
FunctionLibrary
copy()
This method creates a copy of a FunctionLibrary: if the original FunctionLibrary allows new functions to be added, then additions to this copy will not affect the original, or vice versa.
XPathFunctionResolver
getXPathFunctionResolver()
Get the resolver
boolean
isAvailable(StructuredQName functionName, int arity)
Test whether an XPath function with a given name and arity is available.
void
setXPathFunctionResolver(XPathFunctionResolver resolver)
Set the resolver

Constructor Details

XPathFunctionLibrary

public XPathFunctionLibrary()
Construct a XPathFunctionLibrary

Method Details

bind

public Expression bind(StructuredQName functionName,
                       Expression[] staticArgs,
                       StaticContext env)
            throws XPathException
Bind a function, given the URI and local parts of the function name, and the list of expressions supplied as arguments. This method is called at compile time.
Specified by:
bind in interface FunctionLibrary
Parameters:
functionName -
staticArgs - The expressions supplied statically in the function call. The intention is that the static type of the arguments (obtainable via getItemType() and getCardinality() may be used as part of the binding algorithm.
env -
Returns:
An object representing the extension function to be called, if one is found; null if no extension function was found matching the required name, arity, or signature.

copy

public FunctionLibrary copy()
This method creates a copy of a FunctionLibrary: if the original FunctionLibrary allows new functions to be added, then additions to this copy will not affect the original, or vice versa.
Specified by:
copy in interface FunctionLibrary
Returns:
a copy of this function library. This must be an instance of the original class.

getXPathFunctionResolver

public XPathFunctionResolver getXPathFunctionResolver()
Get the resolver
Returns:
the XPathFunctionResolver wrapped by this FunctionLibrary

isAvailable

public boolean isAvailable(StructuredQName functionName,
                           int arity)
Test whether an XPath function with a given name and arity is available. This supports the function-available() function in XSLT. It is thus never used, and always returns false
Specified by:
isAvailable in interface FunctionLibrary
Parameters:
functionName -
arity - The number of arguments. This is set to -1 in the case of the single-argument function-available() function; in this case the method should return true if there is some

setXPathFunctionResolver

public void setXPathFunctionResolver(XPathFunctionResolver resolver)
Set the resolver
Parameters:
resolver - The XPathFunctionResolver wrapped by this FunctionLibrary