Package net.sf.saxon.xpath
Class XPathFunctionLibrary
java.lang.Object
net.sf.saxon.xpath.XPathFunctionLibrary
- All Implemented Interfaces:
Serializable
,FunctionLibrary
The XPathFunctionLibrary is a FunctionLibrary that supports binding of XPath function
calls to instances of the JAXP XPathFunction interface returned by an XPathFunctionResolver.
- See Also:
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionbind
(StructuredQName functionName, Expression[] staticArgs, StaticContext env, Container container) Bind a function, given the URI and local parts of the function name, and the list of expressions supplied as arguments.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.getFunctionSignature
(StructuredQName functionName, int arity) Test whether a function with a given name and arity is available; if so, return its signature.Get the resolvervoid
Set the resolver
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Constructor Details
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XPathFunctionLibrary
public XPathFunctionLibrary()Construct a XPathFunctionLibrary
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Method Details
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setXPathFunctionResolver
Set the resolver- Parameters:
resolver
- The XPathFunctionResolver wrapped by this FunctionLibrary
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getXPathFunctionResolver
Get the resolver- Returns:
- the XPathFunctionResolver wrapped by this FunctionLibrary
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getFunctionSignature
Test whether a function with a given name and arity is available; if so, return its signature. This supports the function-available() function in XSLT; it is also used to support higher-order functions introduced in XQuery 1.1. For this function library the method is never used and therefore returns null.This method may be called either at compile time or at run time. If the function library is to be used only in an XQuery or free-standing XPath environment, this method may throw an UnsupportedOperationException.
- Specified by:
getFunctionSignature
in interfaceFunctionLibrary
- Parameters:
functionName
- the qualified name of the function being calledarity
- 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 function of this name available for calling.- Returns:
- if a function of this name and arity is available for calling, then the type signature of the function, as an array of sequence types in which the zeroth entry represents the return type; or a zero-length array if the function exists but the signature is not known; or null if the function does not exist
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bind
public Expression bind(StructuredQName functionName, Expression[] staticArgs, StaticContext env, Container container) 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 interfaceFunctionLibrary
- 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
-container
-- 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.
- 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.
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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 interfaceFunctionLibrary
- Returns:
- a copy of this function library. This must be an instance of the original class.
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