code: /*
   * 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.
   */
  /*
   * $Id$
   */
  package org.apache.xalan.templates;
  
  import javax.xml.transform.TransformerException;
  
  import org.apache.xalan.transformer.TransformerImpl;
  import org.apache.xpath.XPath;
  import org.apache.xpath.XPathContext;
  import org.apache.xpath.objects.XObject;
  
  /**
   * Implement xsl:if.
   * <pre>
   * <!ELEMENT xsl:if %template;>
   * <!ATTLIST xsl:if
   *   test %expr; #REQUIRED
   *   %space-att;
   * >
   * </pre>
   * @see <a href="http://www.w3.org/TR/xslt#section-Conditional-Processing-with-xsl:if">XXX in XSLT Specification</a>
   * @xsl.usage advanced
   */
  public class ElemIf extends ElemTemplateElement
  {
      static final long serialVersionUID = 2158774632427453022L;
  
    /**
     * The xsl:if element must have a test attribute, which specifies an expression.
     * @serial
     */
    private XPath m_test = null;
  
    /**
     * Set the "test" attribute.
     * The xsl:if element must have a test attribute, which specifies an expression.
     *
     * @param v test attribute to set
     */
    public void setTest(XPath v)
    {
      m_test = v;
    }
  
    /**
     * Get the "test" attribute.
     * The xsl:if element must have a test attribute, which specifies an expression.
     *
     * @return the "test" attribute for this element.
     */
    public XPath getTest()
    {
      return m_test;
    }
  
    /**
     * 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.
     *
     * @param sroot The root stylesheet.
     *
     * @throws TransformerException
     */
    public void compose(StylesheetRoot sroot) throws TransformerException
    {
  
      super.compose(sroot);
  
      java.util.Vector vnames = sroot.getComposeState().getVariableNames();
  
      if (null != m_test)
        m_test.fixupVariables(vnames, sroot.getComposeState().getGlobalsSize());
    }
  
    /**
     * Get an int constant identifying the type of element.
     * @see org.apache.xalan.templates.Constants
     *
     * @return The token ID for this element
     */
    public int getXSLToken()
    {
      return Constants.ELEMNAME_IF;
    }
  
    /**
     * Return the node name.
     *
     * @return the element's name
     */
    public String getNodeName()
    {
      return Constants.ELEMNAME_IF_STRING;
    }
  
    /**
     * Conditionally execute a sub-template.
     * The expression is evaluated and the resulting object is converted
     * to a boolean as if by a call to the boolean function. If the result
     * is true, then the content template is instantiated; otherwise, nothing
     * is created.
     *
     * @param transformer non-null reference to the the current transform-time state.
     *
     * @throws TransformerException
     */
    public void execute(TransformerImpl transformer) throws TransformerException
    {
  
      XPathContext xctxt = transformer.getXPathContext();
      int sourceNode = xctxt.getCurrentNode();
  
      if (transformer.getDebug())
      {
        XObject test = m_test.execute(xctxt, sourceNode, this);
  
        if (transformer.getDebug())
          transformer.getTraceManager().fireSelectedEvent(sourceNode, this,
                  "test", m_test, test);
      
        // xsl:for-each now fires one trace event + one for every
        // iteration; changing xsl:if to fire one regardless of true/false
  
        if (transformer.getDebug())
          transformer.getTraceManager().fireTraceEvent(this);
  
        if (test.bool())
        {
          transformer.executeChildTemplates(this, true);        
        }
  
        if (transformer.getDebug())
          transformer.getTraceManager().fireTraceEndEvent(this);
  
        // I don't think we want this.  -sb
        //  if (transformer.getDebug())
        //    transformer.getTraceManager().fireSelectedEvent(sourceNode, this,
        //            "endTest", m_test, test);
      }
      else if (m_test.bool(xctxt, sourceNode, this))
      {
        transformer.executeChildTemplates(this, true);
      }
      
    }
    
    /**
     * Call the children visitors.
     * @param visitor The visitor whose appropriate method will be called.
     */
    protected void callChildVisitors(XSLTVisitor visitor, boolean callAttrs)
    {
    	if(callAttrs)
    		m_test.getExpression().callVisitors(m_test, visitor);
      super.callChildVisitors(visitor, callAttrs);
    }
  
  }
  