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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2022 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.style;
import net.sf.saxon.expr.Component;
import net.sf.saxon.expr.Expression;
import net.sf.saxon.expr.StaticContext;
import net.sf.saxon.expr.UserFunctionCall;
import net.sf.saxon.expr.instruct.UserFunction;
import net.sf.saxon.functions.FunctionLibrary;
import net.sf.saxon.om.Function;
import net.sf.saxon.trans.SymbolicName;
import net.sf.saxon.trans.Visibility;
import net.sf.saxon.trans.XPathException;
import java.util.List;
/**
* A PublicStylesheetFunctionLibrary filters a StylesheetFunctionLibrary to include only those functions
* whose visibility is final or public. Used by xsl:evaluate
*/
public class PublicStylesheetFunctionLibrary implements FunctionLibrary {
private final FunctionLibrary base;
/**
* Create a FunctionLibrary that provides access to public stylesheet functions
*
* @param base the base function library of which this one is a subset
*/
public PublicStylesheetFunctionLibrary(FunctionLibrary base) {
this.base = base;
}
/**
* 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 The name of the function
* @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 The static context
* @param reasons If no matching function is found by the function library, it may add
* a diagnostic explanation to this list explaining why none of the available
* functions could be used.
* @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 and arity.
*/
@Override
public Expression bind(SymbolicName.F functionName, Expression[] staticArgs, StaticContext env, List reasons) {
Expression baseCall = base.bind(functionName, staticArgs, env, reasons);
if (baseCall instanceof UserFunctionCall) {
Component target = ((UserFunctionCall)baseCall).getTarget();
Visibility v = target.getVisibility();
if (v == Visibility.PUBLIC || v == Visibility.FINAL) {
return baseCall;
} else {
reasons.add("The function exists, but does not have public visibility");
}
}
return null;
}
/**
* 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.
*
* @param functionName the qualified name of the function being called
* @param 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
* @return 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
*/
@Override
public Function getFunctionItem(SymbolicName.F functionName, StaticContext staticContext) throws XPathException {
Function baseFunction = base.getFunctionItem(functionName, staticContext);
if (baseFunction instanceof UserFunction) {
Visibility v = ((UserFunction)baseFunction).getDeclaredVisibility();
if (v == Visibility.PUBLIC || v == Visibility.FINAL) {
return baseFunction;
}
}
return null;
}
/**
* 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 languageLevel the XPath language level (times 10, e.g. 31 for XPath 3.1)
* @return true if a function of this name and arity is available for calling
*/
@Override
public boolean isAvailable(SymbolicName.F functionName, int languageLevel) {
if (base instanceof StylesheetFunctionLibrary) {
StylesheetPackage pack = ((StylesheetFunctionLibrary)base).getStylesheetPackage();
UserFunction fn = pack.getFunction(functionName);
if (fn != null) {
Visibility v = fn.getDeclaredVisibility();
return v == Visibility.PUBLIC || v == Visibility.FINAL;
} else {
return false;
}
} else {
return base.isAvailable(functionName, languageLevel);
}
}
/**
* 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.
*/
@Override
public FunctionLibrary copy() {
return this;
}
}