net.sf.saxon.style

Class StylesheetFunctionLibrary

java.lang.Object

net.sf.saxon.style.StylesheetFunctionLibrary

All Implemented Interfaces:

FunctionLibrary

public class StylesheetFunctionLibrary
extends Object
implements FunctionLibrary

A StylesheetFunctionLibrary contains functions defined by the user in a stylesheet. This library is used at compile time only, as it contains references to the actual XSLFunction objects. Binding to a function in this library registers the function call on a fix-up list to be notified when the actual compiled function becomes available.

Constructor Summary

Constructors

Constructor and Description
StylesheetFunctionLibrary(StylesheetPackage sheet, boolean overrideExtensionFunction) Create a FunctionLibrary that provides access to stylesheet functions

Method Summary

Methods

Modifier and Type	Method and Description
Expression	bind(SymbolicName 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.
Function	getFunctionItem(SymbolicName functionName, StaticContext staticContext) Test whether a function with a given name and arity is available; if so, return a function item that can be dynamically called.
boolean	isAvailable(SymbolicName functionName) Test whether a function with a given name and arity is available
boolean	isOverrideExtensionFunction() Ask whether the functions in this library are "overrideExtensionFunction" functions, that is, defined with xsl:function override="yes".

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StylesheetFunctionLibrary

public StylesheetFunctionLibrary(StylesheetPackage sheet,
                         boolean overrideExtensionFunction)

Create a FunctionLibrary that provides access to stylesheet functions

Parameters:

sheet - The XSLT package

overrideExtensionFunction - set to true if this library is to contain functions specifying override="yes", or to false if it is to contain functions specifying override="no". (XSLT uses two instances of this class, one for overrideExtensionFunction functions and one for non-overrideExtensionFunction functions.)

Method Detail

isOverrideExtensionFunction

public boolean isOverrideExtensionFunction()

Ask whether the functions in this library are "overrideExtensionFunction" functions, that is, defined with xsl:function override="yes".

Returns:

true if these are overrideExtensionFunction functions, false otherwise

bind

public Expression bind(SymbolicName 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 - The name of the function

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 - The static context

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 and arity.

Throws:

XPathException - if a function is found with the required name and arity, but the implementation of the function cannot be loaded or used; or if an error occurs while searching for the function; or if this function library "owns" the namespace containing the function call, but no function was found.

getFunctionItem

public Function getFunctionItem(SymbolicName functionName,
                       StaticContext staticContext)
                         throws XPathException

Test whether a function with a given name and arity is available; if so, return a function item that can be dynamically called.

This supports the function-lookup() function in XPath 3.0.

Specified by:

getFunctionItem in interface FunctionLibrary

Parameters:

functionName - the qualified name of the function being called

staticContext - the static context to be used by the function, in the event that it is a system function with dependencies on the static context

Returns:

if a function of this name and arity is available for calling, then a corresponding function item; or null if the function does not exist

Throws:

XPathException - in the event of certain errors, for example attempting to get a function that is private

isAvailable

public boolean isAvailable(SymbolicName functionName)

Test whether a function with a given name and arity is available

This supports the function-available() function in XSLT.

Specified by:

isAvailable in interface FunctionLibrary

Parameters:

functionName - the qualified name of the function being called

Returns:

true if a function of this name and arity is available for calling

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.