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      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: ElemIf.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.transformer.TransformerImpl;
     26 import org.apache.xpath.XPath;
     27 import org.apache.xpath.XPathContext;
     28 import org.apache.xpath.objects.XObject;
     29 
     30 /**
     31  * Implement xsl:if.
     32  * <pre>
     33  * <!ELEMENT xsl:if %template;>
     34  * <!ATTLIST xsl:if
     35  *   test %expr; #REQUIRED
     36  *   %space-att;
     37  * >
     38  * </pre>
     39  * @see <a href="http://www.w3.org/TR/xslt#section-Conditional-Processing-with-xsl:if">XXX in XSLT Specification</a>
     40  * @xsl.usage advanced
     41  */
     42 public class ElemIf extends ElemTemplateElement
     43 {
     44     static final long serialVersionUID = 2158774632427453022L;
     45 
     46   /**
     47    * The xsl:if element must have a test attribute, which specifies an expression.
     48    * @serial
     49    */
     50   private XPath m_test = null;
     51 
     52   /**
     53    * Set the "test" attribute.
     54    * The xsl:if element must have a test attribute, which specifies an expression.
     55    *
     56    * @param v test attribute to set
     57    */
     58   public void setTest(XPath v)
     59   {
     60     m_test = v;
     61   }
     62 
     63   /**
     64    * Get the "test" attribute.
     65    * The xsl:if element must have a test attribute, which specifies an expression.
     66    *
     67    * @return the "test" attribute for this element.
     68    */
     69   public XPath getTest()
     70   {
     71     return m_test;
     72   }
     73 
     74   /**
     75    * This function is called after everything else has been
     76    * recomposed, and allows the template to set remaining
     77    * values that may be based on some other property that
     78    * depends on recomposition.
     79    *
     80    * @param sroot The root stylesheet.
     81    *
     82    * @throws TransformerException
     83    */
     84   public void compose(StylesheetRoot sroot) throws TransformerException
     85   {
     86 
     87     super.compose(sroot);
     88 
     89     java.util.Vector vnames = sroot.getComposeState().getVariableNames();
     90 
     91     if (null != m_test)
     92       m_test.fixupVariables(vnames, sroot.getComposeState().getGlobalsSize());
     93   }
     94 
     95   /**
     96    * Get an int constant identifying the type of element.
     97    * @see org.apache.xalan.templates.Constants
     98    *
     99    * @return The token ID for this element
    100    */
    101   public int getXSLToken()
    102   {
    103     return Constants.ELEMNAME_IF;
    104   }
    105 
    106   /**
    107    * Return the node name.
    108    *
    109    * @return the element's name
    110    */
    111   public String getNodeName()
    112   {
    113     return Constants.ELEMNAME_IF_STRING;
    114   }
    115 
    116   /**
    117    * Conditionally execute a sub-template.
    118    * The expression is evaluated and the resulting object is converted
    119    * to a boolean as if by a call to the boolean function. If the result
    120    * is true, then the content template is instantiated; otherwise, nothing
    121    * is created.
    122    *
    123    * @param transformer non-null reference to the the current transform-time state.
    124    *
    125    * @throws TransformerException
    126    */
    127   public void execute(TransformerImpl transformer) throws TransformerException
    128   {
    129 
    130     XPathContext xctxt = transformer.getXPathContext();
    131     int sourceNode = xctxt.getCurrentNode();
    132 
    133       if (m_test.bool(xctxt, sourceNode, this)) {
    134           transformer.executeChildTemplates(this, true);
    135       }
    136 
    137   }
    138 
    139   /**
    140    * Call the children visitors.
    141    * @param visitor The visitor whose appropriate method will be called.
    142    */
    143   protected void callChildVisitors(XSLTVisitor visitor, boolean callAttrs)
    144   {
    145   	if(callAttrs)
    146   		m_test.getExpression().callVisitors(m_test, visitor);
    147     super.callChildVisitors(visitor, callAttrs);
    148   }
    149 
    150 }
    151