| /* |
| * 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: ElemVariable.java 468643 2006-10-28 06:56:03Z minchau $ |
| */ |
| package org.apache.xalan.templates; |
| |
| import javax.xml.transform.TransformerException; |
| |
| import org.apache.xalan.transformer.TransformerImpl; |
| import org.apache.xml.utils.QName; |
| import org.apache.xpath.XPath; |
| import org.apache.xpath.XPathContext; |
| import org.apache.xpath.objects.XObject; |
| import org.apache.xpath.objects.XRTreeFrag; |
| import org.apache.xpath.objects.XRTreeFragSelectWrapper; |
| import org.apache.xpath.objects.XString; |
| import org.apache.xalan.res.XSLTErrorResources; |
| |
| /** |
| * Implement xsl:variable. |
| * <pre> |
| * <!ELEMENT xsl:variable %template;> |
| * <!ATTLIST xsl:variable |
| * name %qname; #REQUIRED |
| * select %expr; #IMPLIED |
| * > |
| * </pre> |
| * @see <a href="http://www.w3.org/TR/xslt#variables">variables in XSLT Specification</a> |
| * @xsl.usage advanced |
| */ |
| public class ElemVariable extends ElemTemplateElement |
| { |
| static final long serialVersionUID = 9111131075322790061L; |
| |
| /** |
| * Constructor ElemVariable |
| * |
| */ |
| public ElemVariable(){} |
| |
| /** |
| * This is the index into the stack frame. |
| */ |
| protected int m_index; |
| |
| /** |
| * The stack frame size for this variable if it is a global variable |
| * that declares an RTF, which is equal to the maximum number |
| * of variables that can be declared in the variable at one time. |
| */ |
| int m_frameSize = -1; |
| |
| |
| /** |
| * Sets the relative position of this variable within the stack frame (if local) |
| * or the global area (if global). Note that this should be called only for |
| * global variables since the local position is computed in the compose() method. |
| */ |
| public void setIndex(int index) |
| { |
| m_index = index; |
| } |
| |
| /** |
| * If this element is not at the top-level, get the relative position of the |
| * variable into the stack frame. If this variable is at the top-level, get |
| * the relative position within the global area. |
| */ |
| public int getIndex() |
| { |
| return m_index; |
| } |
| |
| /** |
| * The value of the "select" attribute. |
| * @serial |
| */ |
| private XPath m_selectPattern; |
| |
| /** |
| * Set the "select" attribute. |
| * If the variable-binding element has a select attribute, |
| * then the value of the attribute must be an expression and |
| * the value of the variable is the object that results from |
| * evaluating the expression. In this case, the content |
| * of the variable must be empty. |
| * |
| * @param v Value to set for the "select" attribute. |
| */ |
| public void setSelect(XPath v) |
| { |
| m_selectPattern = v; |
| } |
| |
| /** |
| * Get the "select" attribute. |
| * If the variable-binding element has a select attribute, |
| * then the value of the attribute must be an expression and |
| * the value of the variable is the object that results from |
| * evaluating the expression. In this case, the content |
| * of the variable must be empty. |
| * |
| * @return Value of the "select" attribute. |
| */ |
| public XPath getSelect() |
| { |
| return m_selectPattern; |
| } |
| |
| /** |
| * The value of the "name" attribute. |
| * @serial |
| */ |
| protected QName m_qname; |
| |
| /** |
| * Set the "name" attribute. |
| * Both xsl:variable and xsl:param have a required name |
| * attribute, which specifies the name of the variable. The |
| * value of the name attribute is a QName, which is expanded |
| * as described in [2.4 Qualified Names]. |
| * @see <a href="http://www.w3.org/TR/xslt#qname">qname in XSLT Specification</a> |
| * |
| * @param v Value to set for the "name" attribute. |
| */ |
| public void setName(QName v) |
| { |
| m_qname = v; |
| } |
| |
| /** |
| * Get the "name" attribute. |
| * Both xsl:variable and xsl:param have a required name |
| * attribute, which specifies the name of the variable. The |
| * value of the name attribute is a QName, which is expanded |
| * as described in [2.4 Qualified Names]. |
| * @see <a href="http://www.w3.org/TR/xslt#qname">qname in XSLT Specification</a> |
| * |
| * @return Value of the "name" attribute. |
| */ |
| public QName getName() |
| { |
| return m_qname; |
| } |
| |
| /** |
| * Tells if this is a top-level variable or param, or not. |
| * @serial |
| */ |
| private boolean m_isTopLevel = false; |
| |
| /** |
| * Set if this is a top-level variable or param, or not. |
| * @see <a href="http://www.w3.org/TR/xslt#top-level-variables">top-level-variables in XSLT Specification</a> |
| * |
| * @param v Boolean indicating whether this is a top-level variable |
| * or param, or not. |
| */ |
| public void setIsTopLevel(boolean v) |
| { |
| m_isTopLevel = v; |
| } |
| |
| /** |
| * Get if this is a top-level variable or param, or not. |
| * @see <a href="http://www.w3.org/TR/xslt#top-level-variables">top-level-variables in XSLT Specification</a> |
| * |
| * @return Boolean indicating whether this is a top-level variable |
| * or param, or not. |
| */ |
| public boolean getIsTopLevel() |
| { |
| return m_isTopLevel; |
| } |
| |
| /** |
| * Get an integer representation of the element type. |
| * |
| * @return An integer representation of the element, defined in the |
| * Constants class. |
| * @see org.apache.xalan.templates.Constants |
| */ |
| public int getXSLToken() |
| { |
| return Constants.ELEMNAME_VARIABLE; |
| } |
| |
| /** |
| * Return the node name. |
| * |
| * @return The node name |
| */ |
| public String getNodeName() |
| { |
| return Constants.ELEMNAME_VARIABLE_STRING; |
| } |
| |
| /** |
| * Copy constructor. |
| * |
| * @param param An element created from an xsl:variable |
| * |
| * @throws TransformerException |
| */ |
| public ElemVariable(ElemVariable param) throws TransformerException |
| { |
| |
| m_selectPattern = param.m_selectPattern; |
| m_qname = param.m_qname; |
| m_isTopLevel = param.m_isTopLevel; |
| |
| // m_value = param.m_value; |
| // m_varContext = param.m_varContext; |
| } |
| |
| /** |
| * Execute a variable declaration and push it onto the variable stack. |
| * @see <a href="http://www.w3.org/TR/xslt#variables">variables in XSLT Specification</a> |
| * |
| * @param transformer non-null reference to the the current transform-time state. |
| * |
| * @throws TransformerException |
| */ |
| public void execute(TransformerImpl transformer) throws TransformerException |
| { |
| |
| int sourceNode = transformer.getXPathContext().getCurrentNode(); |
| |
| XObject var = getValue(transformer, sourceNode); |
| |
| // transformer.getXPathContext().getVarStack().pushVariable(m_qname, var); |
| transformer.getXPathContext().getVarStack().setLocalVariable(m_index, var); |
| } |
| |
| /** |
| * Get the XObject representation of the variable. |
| * |
| * @param transformer non-null reference to the the current transform-time state. |
| * @param sourceNode non-null reference to the <a href="http://www.w3.org/TR/xslt#dt-current-node">current source node</a>. |
| * |
| * @return the XObject representation of the variable. |
| * |
| * @throws TransformerException |
| */ |
| public XObject getValue(TransformerImpl transformer, int sourceNode) |
| throws TransformerException |
| { |
| |
| XObject var; |
| XPathContext xctxt = transformer.getXPathContext(); |
| |
| xctxt.pushCurrentNode(sourceNode); |
| |
| try |
| { |
| if (null != m_selectPattern) |
| { |
| var = m_selectPattern.execute(xctxt, sourceNode, this); |
| |
| var.allowDetachToRelease(false); |
| } |
| else if (null == getFirstChildElem()) |
| { |
| var = XString.EMPTYSTRING; |
| } |
| else |
| { |
| |
| // Use result tree fragment. |
| // Global variables may be deferred (see XUnresolvedVariable) and hence |
| // need to be assigned to a different set of DTMs than local variables |
| // so they aren't popped off the stack on return from a template. |
| int df; |
| |
| // Bugzilla 7118: A variable set via an RTF may create local |
| // variables during that computation. To keep them from overwriting |
| // variables at this level, push a new variable stack. |
| ////// PROBLEM: This is provoking a variable-used-before-set |
| ////// problem in parameters. Needs more study. |
| try |
| { |
| //////////xctxt.getVarStack().link(0); |
| if(m_parentNode instanceof Stylesheet) // Global variable |
| df = transformer.transformToGlobalRTF(this); |
| else |
| df = transformer.transformToRTF(this); |
| } |
| finally{ |
| //////////////xctxt.getVarStack().unlink(); |
| } |
| |
| var = new XRTreeFrag(df, xctxt, this); |
| } |
| } |
| finally |
| { |
| xctxt.popCurrentNode(); |
| } |
| |
| return var; |
| } |
| |
| |
| /** |
| * This function is called after everything else has been |
| * recomposed, and allows the template to set remaining |
| * values that may be based on some other property that |
| * depends on recomposition. |
| */ |
| public void compose(StylesheetRoot sroot) throws TransformerException |
| { |
| // See if we can reduce an RTF to a select with a string expression. |
| if(null == m_selectPattern |
| && sroot.getOptimizer()) |
| { |
| XPath newSelect = rewriteChildToExpression(this); |
| if(null != newSelect) |
| m_selectPattern = newSelect; |
| } |
| |
| StylesheetRoot.ComposeState cstate = sroot.getComposeState(); |
| |
| // This should be done before addVariableName, so we don't have visibility |
| // to the variable now being defined. |
| java.util.Vector vnames = cstate.getVariableNames(); |
| if(null != m_selectPattern) |
| m_selectPattern.fixupVariables(vnames, cstate.getGlobalsSize()); |
| |
| // Only add the variable if this is not a global. If it is a global, |
| // it was already added by stylesheet root. |
| if(!(m_parentNode instanceof Stylesheet) && m_qname != null) |
| { |
| m_index = cstate.addVariableName(m_qname) - cstate.getGlobalsSize(); |
| } |
| else if (m_parentNode instanceof Stylesheet) |
| { |
| // If this is a global, then we need to treat it as if it's a xsl:template, |
| // and count the number of variables it contains. So we set the count to |
| // zero here. |
| cstate.resetStackFrameSize(); |
| } |
| |
| // This has to be done after the addVariableName, so that the variable |
| // pushed won't be immediately popped again in endCompose. |
| super.compose(sroot); |
| } |
| |
| /** |
| * This after the template's children have been composed. We have to get |
| * the count of how many variables have been declared, so we can do a link |
| * and unlink. |
| */ |
| public void endCompose(StylesheetRoot sroot) throws TransformerException |
| { |
| super.endCompose(sroot); |
| if(m_parentNode instanceof Stylesheet) |
| { |
| StylesheetRoot.ComposeState cstate = sroot.getComposeState(); |
| m_frameSize = cstate.getFrameSize(); |
| cstate.resetStackFrameSize(); |
| } |
| } |
| |
| |
| |
| // /** |
| // * This after the template's children have been composed. |
| // */ |
| // public void endCompose() throws TransformerException |
| // { |
| // super.endCompose(); |
| // } |
| |
| |
| /** |
| * If the children of a variable is a single xsl:value-of or text literal, |
| * it is cheaper to evaluate this as an expression, so try and adapt the |
| * child an an expression. |
| * |
| * @param varElem Should be a ElemParam, ElemVariable, or ElemWithParam. |
| * |
| * @return An XPath if rewrite is possible, else null. |
| * |
| * @throws TransformerException |
| */ |
| static XPath rewriteChildToExpression(ElemTemplateElement varElem) |
| throws TransformerException |
| { |
| |
| ElemTemplateElement t = varElem.getFirstChildElem(); |
| |
| // Down the line this can be done with multiple string objects using |
| // the concat function. |
| if (null != t && null == t.getNextSiblingElem()) |
| { |
| int etype = t.getXSLToken(); |
| |
| if (Constants.ELEMNAME_VALUEOF == etype) |
| { |
| ElemValueOf valueof = (ElemValueOf) t; |
| |
| // %TBD% I'm worried about extended attributes here. |
| if (valueof.getDisableOutputEscaping() == false |
| && valueof.getDOMBackPointer() == null) |
| { |
| varElem.m_firstChild = null; |
| |
| return new XPath(new XRTreeFragSelectWrapper(valueof.getSelect().getExpression())); |
| } |
| } |
| else if (Constants.ELEMNAME_TEXTLITERALRESULT == etype) |
| { |
| ElemTextLiteral lit = (ElemTextLiteral) t; |
| |
| if (lit.getDisableOutputEscaping() == false |
| && lit.getDOMBackPointer() == null) |
| { |
| String str = lit.getNodeValue(); |
| XString xstr = new XString(str); |
| |
| varElem.m_firstChild = null; |
| |
| return new XPath(new XRTreeFragSelectWrapper(xstr)); |
| } |
| } |
| } |
| |
| return null; |
| } |
| |
| /** |
| * This function is called during recomposition to |
| * control how this element is composed. |
| * @param root The root stylesheet for this transformation. |
| */ |
| public void recompose(StylesheetRoot root) |
| { |
| root.recomposeVariables(this); |
| } |
| |
| /** |
| * Set the parent as an ElemTemplateElement. |
| * |
| * @param p This node's parent as an ElemTemplateElement |
| */ |
| public void setParentElem(ElemTemplateElement p) |
| { |
| super.setParentElem(p); |
| p.m_hasVariableDecl = true; |
| } |
| |
| /** |
| * Accept a visitor and call the appropriate method |
| * for this class. |
| * |
| * @param visitor The visitor whose appropriate method will be called. |
| * @return true if the children of the object should be visited. |
| */ |
| protected boolean accept(XSLTVisitor visitor) |
| { |
| return visitor.visitVariableOrParamDecl(this); |
| } |
| |
| |
| /** |
| * Call the children visitors. |
| * @param visitor The visitor whose appropriate method will be called. |
| */ |
| protected void callChildVisitors(XSLTVisitor visitor, boolean callAttrs) |
| { |
| if(null != m_selectPattern) |
| m_selectPattern.getExpression().callVisitors(m_selectPattern, visitor); |
| super.callChildVisitors(visitor, callAttrs); |
| } |
| |
| /** |
| * Tell if this is a psuedo variable reference, declared by Xalan instead |
| * of by the user. |
| */ |
| public boolean isPsuedoVar() |
| { |
| java.lang.String ns = m_qname.getNamespaceURI(); |
| if((null != ns) && ns.equals(RedundentExprEliminator.PSUEDOVARNAMESPACE)) |
| { |
| if(m_qname.getLocalName().startsWith("#")) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Add a child to the child list. If the select attribute |
| * is present, an error will be raised. |
| * |
| * @param elem New element to append to this element's children list |
| * |
| * @return null if the select attribute was present, otherwise the |
| * child just added to the child list |
| */ |
| public ElemTemplateElement appendChild(ElemTemplateElement elem) |
| { |
| // cannot have content and select |
| if (m_selectPattern != null) |
| { |
| error(XSLTErrorResources.ER_CANT_HAVE_CONTENT_AND_SELECT, |
| new Object[]{"xsl:" + this.getNodeName()}); |
| return null; |
| } |
| return super.appendChild(elem); |
| } |
| |
| } |