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 * Licensed to the Apache Software Foundation (ASF) under one or more
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 * The ASF licenses this file to You under the Apache License, Version 2.0
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package com.sun.org.apache.xalan.internal.xsltc.compiler;

import java.util.Vector;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

Author:Jacek Ambroziak, Santiago Pericas-Geertsen
/** * @author Jacek Ambroziak * @author Santiago Pericas-Geertsen */
final class ElementAvailableCall extends FunctionCall { public ElementAvailableCall(QName fname, Vector arguments) { super(fname, arguments); }
Force the argument to this function to be a literal string.
/** * Force the argument to this function to be a literal string. */
public Type typeCheck(SymbolTable stable) throws TypeCheckError { if (argument() instanceof LiteralExpr) { return _type = Type.Boolean; } ErrorMsg err = new ErrorMsg(ErrorMsg.NEED_LITERAL_ERR, "element-available", this); throw new TypeCheckError(err); }
Returns an object representing the compile-time evaluation of an expression. We are only using this for function-available and element-available at this time.
/** * Returns an object representing the compile-time evaluation * of an expression. We are only using this for function-available * and element-available at this time. */
public Object evaluateAtCompileTime() { return getResult() ? Boolean.TRUE : Boolean.FALSE; }
Returns the result that this function will return
/** * Returns the result that this function will return */
public boolean getResult() { try { final LiteralExpr arg = (LiteralExpr) argument(); final String qname = arg.getValue(); final int index = qname.indexOf(':'); final String localName = (index > 0) ? qname.substring(index + 1) : qname; return getParser().elementSupported(arg.getNamespace(), localName); } catch (ClassCastException e) { return false; } }
Calls to 'element-available' are resolved at compile time since the namespaces declared in the stylsheet are not available at run time. Consequently, arguments to this function must be literals.
/** * Calls to 'element-available' are resolved at compile time since * the namespaces declared in the stylsheet are not available at run * time. Consequently, arguments to this function must be literals. */
public void translate(ClassGenerator classGen, MethodGenerator methodGen) { final ConstantPoolGen cpg = classGen.getConstantPool(); final boolean result = getResult(); methodGen.getInstructionList().append(new PUSH(cpg, result)); } }