/* * 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. */ package com.sun.org.apache.xpath.internal.operations; import javax.xml.transform.TransformerException; import com.sun.org.apache.xalan.internal.res.XSLMessages; import com.sun.org.apache.xml.internal.utils.QName; import com.sun.org.apache.xpath.internal.Expression; import com.sun.org.apache.xpath.internal.ExpressionOwner; import com.sun.org.apache.xpath.internal.XPath; import com.sun.org.apache.xpath.internal.XPathContext; import com.sun.org.apache.xpath.internal.XPathVisitor; import com.sun.org.apache.xpath.internal.axes.PathComponent; import com.sun.org.apache.xpath.internal.axes.WalkerFactory; import com.sun.org.apache.xpath.internal.objects.XNodeSet; import com.sun.org.apache.xpath.internal.objects.XObject; import com.sun.org.apache.xpath.internal.res.XPATHErrorResources; /** * The variable reference expression executer. */ public class Variable extends Expression implements PathComponent { /** Tell if fixupVariables was called. * @serial */ private boolean m_fixUpWasCalled = false; /** The qualified name of the variable. * @serial */ protected QName m_qname; /** * The index of the variable, which is either an absolute index to a * global, or, if higher than the globals area, must be adjusted by adding * the offset to the current stack frame. */ protected int m_index; /** * Set the index for the variable into the stack. For advanced use only. You * must know what you are doing to use this. * * @param index a global or local index. */ public void setIndex(int index) { m_index = index; } /** * Set the index for the variable into the stack. For advanced use only. * * @return index a global or local index. */ public int getIndex() { return m_index; } /** * Set whether or not this is a global reference. For advanced use only. * * @param isGlobal true if this should be a global variable reference. */ public void setIsGlobal(boolean isGlobal) { m_isGlobal = isGlobal; } /** * Set the index for the variable into the stack. For advanced use only. * * @return true if this should be a global variable reference. */ public boolean getGlobal() { return m_isGlobal; } protected boolean m_isGlobal = false; /** * 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). */ public void fixupVariables(java.util.Vector vars, int globalsSize) { m_fixUpWasCalled = true; int sz = vars.size(); for (int i = vars.size()-1; i >= 0; i--) { QName qn = (QName)vars.elementAt(i); // System.out.println("qn: "+qn); if(qn.equals(m_qname)) { if(i < globalsSize) { m_isGlobal = true; m_index = i; } else { m_index = i-globalsSize; } return; } } java.lang.String msg = XSLMessages.createXPATHMessage(XPATHErrorResources.ER_COULD_NOT_FIND_VAR, new Object[]{m_qname.toString()}); TransformerException te = new TransformerException(msg, this); throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(te); } /** * Set the qualified name of the variable. * * @param qname Must be a non-null reference to a qualified name. */ public void setQName(QName qname) { m_qname = qname; } /** * Get the qualified name of the variable. * * @return A non-null reference to a qualified name. */ public QName getQName() { return m_qname; } /** * Execute an expression in the XPath runtime context, and return the * result of the expression. * * * @param xctxt The XPath runtime context. * * @return The result of the expression in the form of a XObject. * * @throws javax.xml.transform.TransformerException if a runtime exception * occurs. */ public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException { return execute(xctxt, false); } /** * Dereference the variable, and return the reference value. Note that lazy * evaluation will occur. If a variable within scope is not found, a warning * will be sent to the error listener, and an empty nodeset will be returned. * * * @param xctxt The runtime execution context. * * @return The evaluated variable, or an empty nodeset if not found. * * @throws javax.xml.transform.TransformerException */ public XObject execute(XPathContext xctxt, boolean destructiveOK) throws javax.xml.transform.TransformerException { com.sun.org.apache.xml.internal.utils.PrefixResolver xprefixResolver = xctxt.getNamespaceContext(); XObject result; // Is the variable fetched always the same? // XObject result = xctxt.getVariable(m_qname); if(m_fixUpWasCalled) { if(m_isGlobal) result = xctxt.getVarStack().getGlobalVariable(xctxt, m_index, destructiveOK); else result = xctxt.getVarStack().getLocalVariable(xctxt, m_index, destructiveOK); } else { result = xctxt.getVarStack().getVariableOrParam(xctxt,m_qname); } if (null == result) { // This should now never happen... warn(xctxt, XPATHErrorResources.WG_ILLEGAL_VARIABLE_REFERENCE, new Object[]{ m_qname.getLocalPart() }); //"VariableReference given for variable out "+ // (new RuntimeException()).printStackTrace(); // error(xctxt, XPATHErrorResources.ER_COULDNOT_GET_VAR_NAMED, // new Object[]{ m_qname.getLocalPart() }); //"Could not get variable named "+varName); result = new XNodeSet(xctxt.getDTMManager()); } return result; // } // else // { // // Hack city... big time. This is needed to evaluate xpaths from extensions, // // pending some bright light going off in my head. Some sort of callback? // synchronized(this) // { // com.sun.org.apache.xalan.internal.templates.ElemVariable vvar= getElemVariable(); // if(null != vvar) // { // m_index = vvar.getIndex(); // m_isGlobal = vvar.getIsTopLevel(); // m_fixUpWasCalled = true; // return execute(xctxt); // } // } // throw new javax.xml.transform.TransformerException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_VAR_NOT_RESOLVABLE, new Object[]{m_qname.toString()})); //"Variable not resolvable: "+m_qname); // } } /** * Get the XSLT ElemVariable that this sub-expression references. In order for * this to work, the SourceLocator must be the owning ElemTemplateElement. * @return The dereference to the ElemVariable, or null if not found. */ /* public com.sun.org.apache.xalan.internal.templates.ElemVariable getElemVariable() { // Get the current ElemTemplateElement, and then walk backwards in // document order, searching // for an xsl:param element or xsl:variable element that matches our // qname. If we reach the top level, use the StylesheetRoot's composed // list of top level variables and parameters. com.sun.org.apache.xpath.internal.ExpressionNode owner = getExpressionOwner(); if (null != owner && owner instanceof com.sun.org.apache.xalan.internal.templates.ElemTemplateElement) { com.sun.org.apache.xalan.internal.templates.ElemVariable vvar; com.sun.org.apache.xalan.internal.templates.ElemTemplateElement prev = (com.sun.org.apache.xalan.internal.templates.ElemTemplateElement) owner; if (!(prev instanceof com.sun.org.apache.xalan.internal.templates.Stylesheet)) { while ( !(prev.getParentNode() instanceof com.sun.org.apache.xalan.internal.templates.Stylesheet) ) { com.sun.org.apache.xalan.internal.templates.ElemTemplateElement savedprev = prev; while (null != (prev = prev.getPreviousSiblingElem())) { if(prev instanceof com.sun.org.apache.xalan.internal.templates.ElemVariable) { vvar = (com.sun.org.apache.xalan.internal.templates.ElemVariable) prev; if (vvar.getName().equals(m_qname)) { return vvar; } } } prev = savedprev.getParentElem(); } } vvar = prev.getStylesheetRoot().getVariableOrParamComposed(m_qname); if (null != vvar) { return vvar; } } return null; } */ /** * Tell if this expression returns a stable number that will not change during * iterations within the expression. This is used to determine if a proximity * position predicate can indicate that no more searching has to occur. * * * @return true if the expression represents a stable number. */ public boolean isStableNumber() { return true; } /** * Get the analysis bits for this walker, as defined in the WalkerFactory. * @return One of WalkerFactory#BIT_DESCENDANT, etc. */ public int getAnalysisBits() { // <<<<<<< TIGER SPECIFIC CHANGE >>>>>>>>> // As we are not supporting Xalan interpretive we are taking away the functionality // dependent on XSLT interpretive Transformer. Only way supported is to use XSLTC // and the execution path needed for supporting standard XPath API defined by // JAXP 1.3 . return WalkerFactory.BIT_FILTER; } /** * @see XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor) */ public void callVisitors(ExpressionOwner owner, XPathVisitor visitor) { visitor.visitVariableRef(owner, this); } /** * @see Expression#deepEquals(Expression) */ public boolean deepEquals(Expression expr) { if(!isSameClass(expr)) return false; if(!m_qname.equals(((Variable)expr).m_qname)) return false; // We have to make sure that the qname really references // the same variable element. // <<<<<<< TIGER SPECIFIC CHANGE >>>>>>>>> // As we are not supporting Xalan interpretive we are taking away the functionality // dependent on XSLT interpretive Transformer. Only way supported is to use XSLTC // and the execution path needed for supporting standard XPath API defined by // JAXP 1.3 . return true; } static final java.lang.String PSUEDOVARNAMESPACE = "http://xml.apache.org/xalan/psuedovar"; /** * Tell if this is a psuedo variable reference, declared by Xalan instead * of by the user. */ public boolean isPsuedoVarRef() { java.lang.String ns = m_qname.getNamespaceURI(); if((null != ns) && ns.equals(PSUEDOVARNAMESPACE)) { if(m_qname.getLocalName().startsWith("#")) return true; } return false; } }