| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 468655 2006-10-28 07:12:06Z minchau $ |
| */ |
| package org.apache.xpath.functions; |
| |
| import java.util.Vector; |
| |
| import org.apache.xalan.res.XSLMessages; |
| import org.apache.xpath.Expression; |
| import org.apache.xpath.ExpressionNode; |
| import org.apache.xpath.ExpressionOwner; |
| import org.apache.xpath.ExtensionsProvider; |
| import org.apache.xpath.XPathContext; |
| import org.apache.xpath.XPathVisitor; |
| import org.apache.xpath.objects.XNull; |
| import org.apache.xpath.objects.XObject; |
| import org.apache.xpath.res.XPATHErrorResources; |
| import org.apache.xpath.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; |
| } |
| } |