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Java example source code file (FuncExtFunction.java)
The FuncExtFunction.java Java example source code/* * reserved comment block * DO NOT REMOVE OR ALTER! */ /* * Copyright 1999-2004 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * $Id: FuncExtFunction.java,v 1.2.4.2 2005/09/14 20:18:43 jeffsuttor Exp $ */ package com.sun.org.apache.xpath.internal.functions; import java.util.Vector; import com.sun.org.apache.xalan.internal.res.XSLMessages; import com.sun.org.apache.xpath.internal.Expression; import com.sun.org.apache.xpath.internal.ExpressionNode; import com.sun.org.apache.xpath.internal.ExpressionOwner; import com.sun.org.apache.xpath.internal.ExtensionsProvider; import com.sun.org.apache.xpath.internal.XPathContext; import com.sun.org.apache.xpath.internal.XPathVisitor; import com.sun.org.apache.xpath.internal.objects.XNull; import com.sun.org.apache.xpath.internal.objects.XObject; import com.sun.org.apache.xpath.internal.res.XPATHErrorResources; import com.sun.org.apache.xpath.internal.res.XPATHMessages; /** * An object of this class represents an extension call expression. When * the expression executes, it calls ExtensionsTable#extFunction, and then * converts the result to the appropriate XObject. * @xsl.usage advanced */ public class FuncExtFunction extends Function { static final long serialVersionUID = 5196115554693708718L; /** * The namespace for the extension function, which should not normally * be null or empty. * @serial */ String m_namespace; /** * The local name of the extension. * @serial */ String m_extensionName; /** * Unique method key, which is passed to ExtensionsTable#extFunction in * order to allow caching of the method. * @serial */ Object m_methodKey; /** * Array of static expressions which represent the parameters to the * function. * @serial */ Vector m_argVec = new Vector(); /** * This function is used to fixup variables from QNames to stack frame * indexes at stylesheet build time. * @param vars List of QNames that correspond to variables. This list * should be searched backwards for the first qualified name that * corresponds to the variable reference qname. The position of the * QName in the vector from the start of the vector will be its position * in the stack frame (but variables above the globalsTop value will need * to be offset to the current stack frame). * NEEDSDOC @param globalsSize */ public void fixupVariables(java.util.Vector vars, int globalsSize) { if (null != m_argVec) { int nArgs = m_argVec.size(); for (int i = 0; i < nArgs; i++) { Expression arg = (Expression) m_argVec.elementAt(i); arg.fixupVariables(vars, globalsSize); } } } /** * Return the namespace of the extension function. * * @return The namespace of the extension function. */ public String getNamespace() { return m_namespace; } /** * Return the name of the extension function. * * @return The name of the extension function. */ public String getFunctionName() { return m_extensionName; } /** * Return the method key of the extension function. * * @return The method key of the extension function. */ public Object getMethodKey() { return m_methodKey; } /** * Return the nth argument passed to the extension function. * * @param n The argument number index. * @return The Expression object at the given index. */ public Expression getArg(int n) { if (n >= 0 && n < m_argVec.size()) return (Expression) m_argVec.elementAt(n); else return null; } /** * Return the number of arguments that were passed * into this extension function. * * @return The number of arguments. */ public int getArgCount() { return m_argVec.size(); } /** * Create a new FuncExtFunction based on the qualified name of the extension, * and a unique method key. * * @param namespace The namespace for the extension function, which should * not normally be null or empty. * @param extensionName The local name of the extension. * @param methodKey Unique method key, which is passed to * ExtensionsTable#extFunction in order to allow caching * of the method. */ public FuncExtFunction(java.lang.String namespace, java.lang.String extensionName, Object methodKey) { //try{throw new Exception("FuncExtFunction() " + namespace + " " + extensionName);} catch (Exception e){e.printStackTrace();} m_namespace = namespace; m_extensionName = extensionName; m_methodKey = methodKey; } /** * Execute the function. The function must return * a valid object. * @param xctxt The current execution context. * @return A valid XObject. * * @throws javax.xml.transform.TransformerException */ public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException { if (xctxt.isSecureProcessing()) throw new javax.xml.transform.TransformerException( XPATHMessages.createXPATHMessage( XPATHErrorResources.ER_EXTENSION_FUNCTION_CANNOT_BE_INVOKED, new Object[] {toString()})); XObject result; Vector argVec = new Vector(); int nArgs = m_argVec.size(); for (int i = 0; i < nArgs; i++) { Expression arg = (Expression) m_argVec.elementAt(i); XObject xobj = arg.execute(xctxt); /* * Should cache the arguments for func:function */ xobj.allowDetachToRelease(false); argVec.addElement(xobj); } //dml ExtensionsProvider extProvider = (ExtensionsProvider)xctxt.getOwnerObject(); Object val = extProvider.extFunction(this, argVec); if (null != val) { result = XObject.create(val, xctxt); } else { result = new XNull(); } return result; } /** * Set an argument expression for a function. This method is called by the * XPath compiler. * * @param arg non-null expression that represents the argument. * @param argNum The argument number index. * * @throws WrongNumberArgsException If the argNum parameter is beyond what * is specified for this function. */ public void setArg(Expression arg, int argNum) throws WrongNumberArgsException { m_argVec.addElement(arg); arg.exprSetParent(this); } /** * Check that the number of arguments passed to this function is correct. * * * @param argNum The number of arguments that is being passed to the function. * * @throws WrongNumberArgsException */ public void checkNumberArgs(int argNum) throws WrongNumberArgsException{} class ArgExtOwner implements ExpressionOwner { Expression m_exp; ArgExtOwner(Expression exp) { m_exp = exp; } /** * @see ExpressionOwner#getExpression() */ public Expression getExpression() { return m_exp; } /** * @see ExpressionOwner#setExpression(Expression) */ public void setExpression(Expression exp) { exp.exprSetParent(FuncExtFunction.this); m_exp = exp; } } /** * Call the visitors for the function arguments. */ public void callArgVisitors(XPathVisitor visitor) { for (int i = 0; i < m_argVec.size(); i++) { Expression exp = (Expression)m_argVec.elementAt(i); exp.callVisitors(new ArgExtOwner(exp), visitor); } } /** * Set the parent node. * For an extension function, we also need to set the parent * node for all argument expressions. * * @param n The parent node */ public void exprSetParent(ExpressionNode n) { super.exprSetParent(n); int nArgs = m_argVec.size(); for (int i = 0; i < nArgs; i++) { Expression arg = (Expression) m_argVec.elementAt(i); arg.exprSetParent(n); } } /** * Constructs and throws a WrongNumberArgException with the appropriate * message for this function object. This class supports an arbitrary * number of arguments, so this method must never be called. * * @throws WrongNumberArgsException */ protected void reportWrongNumberArgs() throws WrongNumberArgsException { String fMsg = XSLMessages.createXPATHMessage( XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION, new Object[]{ "Programmer's assertion: the method FunctionMultiArgs.reportWrongNumberArgs() should never be called." }); throw new RuntimeException(fMsg); } /** * Return the name of the extesion function in string format */ public String toString() { if (m_namespace != null && m_namespace.length() > 0) return "{" + m_namespace + "}" + m_extensionName; else return m_extensionName; } } Other Java examples (source code examples)Here is a short list of links related to this Java FuncExtFunction.java source code file: |
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