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An OSGi bundle for Saxon-HE
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.xpath;
import net.sf.saxon.expr.Container;
import net.sf.saxon.expr.Expression;
import net.sf.saxon.expr.StaticContext;
import net.sf.saxon.functions.FunctionLibrary;
import net.sf.saxon.om.FunctionItem;
import net.sf.saxon.om.StructuredQName;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.FunctionItemType;
import net.sf.saxon.value.SequenceType;
import javax.xml.namespace.QName;
import javax.xml.xpath.XPathFunction;
import javax.xml.xpath.XPathFunctionResolver;
import java.util.Arrays;
/**
* The XPathFunctionLibrary is a FunctionLibrary that supports binding of XPath function
* calls to instances of the JAXP XPathFunction interface returned by an XPathFunctionResolver.
*/
public class XPathFunctionLibrary implements FunctionLibrary {
private XPathFunctionResolver resolver;
/**
* Construct a XPathFunctionLibrary
*/
public XPathFunctionLibrary() {
}
/**
* Set the resolver
* @param resolver The XPathFunctionResolver wrapped by this FunctionLibrary
*/
public void setXPathFunctionResolver(XPathFunctionResolver resolver) {
this.resolver = resolver;
}
/**
* Get the resolver
* @return the XPathFunctionResolver wrapped by this FunctionLibrary
*/
public XPathFunctionResolver getXPathFunctionResolver() {
return resolver;
}
/**
* 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.
*
*
* @param functionName
* @param arity
* @param 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.
* @param env
* @param container
* @return 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.
*/
/*@Nullable*/ public Expression bind(/*@NotNull*/ StructuredQName functionName, /*@NotNull*/ int arity, Expression[] staticArgs, StaticContext env, Container container)
throws XPathException {
if (resolver == null) {
return null;
}
QName name = new QName(functionName.getURI(), functionName.getLocalPart());
XPathFunction function = resolver.resolveFunction(name, staticArgs.length);
if (function == null) {
return null;
}
XPathFunctionCall fc = new XPathFunctionCall(function);
fc.setArguments(staticArgs);
return fc;
}
/**
* Test whether a function with a given name and arity is available
* This supports the function-available() function in XSLT.
*
* @param functionName the qualified name of the function being called
* @param arity The number of arguments.
* @return true if a function of this name and arity is available for calling
*/
public boolean isAvailable(StructuredQName functionName, int arity) {
return resolver != null &&
resolver.resolveFunction(
new QName(functionName.getURI(), functionName.getLocalPart()), arity) != null;
}
/**
* 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.
*
* @return a copy of this function library. This must be an instance of the original class.
*/
/*@NotNull*/ public FunctionLibrary copy() {
XPathFunctionLibrary xfl = new XPathFunctionLibrary();
xfl.resolver = resolver;
return xfl;
}
}