1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 /* 19 * $Id: ElemExsltFunction.java 468643 2006-10-28 06:56:03Z minchau $ 20 */ 21 package org.apache.xalan.templates; 22 23 import javax.xml.transform.TransformerException; 24 25 import org.apache.xalan.extensions.ExtensionNamespaceSupport; 26 import org.apache.xalan.transformer.TransformerImpl; 27 import org.apache.xpath.VariableStack; 28 import org.apache.xpath.XPathContext; 29 import org.apache.xpath.objects.XObject; 30 31 import org.w3c.dom.Node; 32 import org.w3c.dom.NodeList; 33 34 35 /** 36 * Implement func:function. 37 * @xsl.usage advanced 38 */ 39 public class ElemExsltFunction extends ElemTemplate 40 { 41 static final long serialVersionUID = 272154954793534771L; 42 /** 43 * Get an integer representation of the element type. 44 * 45 * @return An integer representation of the element, defined in the 46 * Constants class. 47 * @see org.apache.xalan.templates.Constants 48 */ getXSLToken()49 public int getXSLToken() 50 { 51 return Constants.EXSLT_ELEMNAME_FUNCTION; 52 } 53 54 /** 55 * Return the node name, defined in the 56 * Constants class. 57 * @see org.apache.xalan.templates.Constants 58 * @return The node name 59 * 60 */ getNodeName()61 public String getNodeName() 62 { 63 return Constants.EXSLT_ELEMNAME_FUNCTION_STRING; 64 } 65 execute(TransformerImpl transformer, XObject[] args)66 public void execute(TransformerImpl transformer, XObject[] args) 67 throws TransformerException 68 { 69 XPathContext xctxt = transformer.getXPathContext(); 70 VariableStack vars = xctxt.getVarStack(); 71 72 // Increment the frame bottom of the variable stack by the 73 // frame size 74 int thisFrame = vars.getStackFrame(); 75 int nextFrame = vars.link(m_frameSize); 76 77 if (m_inArgsSize < args.length) { 78 throw new TransformerException ("function called with too many args"); 79 } 80 81 // Set parameters, 82 // have to clear the section of the stack frame that has params. 83 if (m_inArgsSize > 0) { 84 vars.clearLocalSlots(0, m_inArgsSize); 85 86 if (args.length > 0) { 87 vars.setStackFrame(thisFrame); 88 NodeList children = this.getChildNodes(); 89 90 for (int i = 0; i < args.length; i ++) { 91 Node child = children.item(i); 92 if (children.item(i) instanceof ElemParam) { 93 ElemParam param = (ElemParam)children.item(i); 94 vars.setLocalVariable(param.getIndex(), args[i], nextFrame); 95 } 96 } 97 98 vars.setStackFrame(nextFrame); 99 } 100 } 101 102 // Removed ElemTemplate 'push' and 'pop' of RTFContext, in order to avoid losing the RTF context 103 // before a value can be returned. ElemExsltFunction operates in the scope of the template that called 104 // the function. 105 // xctxt.pushRTFContext(); 106 107 vars.setStackFrame(nextFrame); 108 transformer.executeChildTemplates(this, true); 109 110 // Reset the stack frame after the function call 111 vars.unlink(thisFrame); 112 113 // Following ElemTemplate 'pop' removed -- see above. 114 // xctxt.popRTFContext(); 115 116 } 117 118 /** 119 * Called after everything else has been 120 * recomposed, and allows the function to set remaining 121 * values that may be based on some other property that 122 * depends on recomposition. 123 */ compose(StylesheetRoot sroot)124 public void compose(StylesheetRoot sroot) throws TransformerException 125 { 126 super.compose(sroot); 127 128 // Register the function namespace (if not already registered). 129 String namespace = getName().getNamespace(); 130 String handlerClass = sroot.getExtensionHandlerClass(); 131 Object[] args ={namespace, sroot}; 132 ExtensionNamespaceSupport extNsSpt = 133 new ExtensionNamespaceSupport(namespace, handlerClass, args); 134 sroot.getExtensionNamespacesManager().registerExtension(extNsSpt); 135 // Make sure there is a handler for the EXSLT functions namespace 136 // -- for isElementAvailable(). 137 if (!(namespace.equals(Constants.S_EXSLT_FUNCTIONS_URL))) 138 { 139 namespace = Constants.S_EXSLT_FUNCTIONS_URL; 140 args = new Object[]{namespace, sroot}; 141 extNsSpt = new ExtensionNamespaceSupport(namespace, handlerClass, args); 142 sroot.getExtensionNamespacesManager().registerExtension(extNsSpt); 143 } 144 } 145 } 146