avt.java

来自「java jdk 1.4的源码」· Java 代码 · 共 643 行 · 第 1/2 页

                          // Proper close of attribute template.
                          // Evaluate the expression.
                          buffer.setLength(0);

                          XPath xpath =
                                       handler.createXPath(exprBuffer.toString(), owner);

                          m_parts.addElement(new AVTPartXPath(xpath));

                          lookahead = null;  // breaks out of inner while loop

                          break;
                        }
                      default :
                        {

                          // part of the template stuff, just add it.
                          exprBuffer.append(lookahead);

                          lookahead = tokenizer.nextToken();
                        }
                      }  // end inner switch
                    }  // end if lookahead length == 1
                    else
                    {

                      // part of the template stuff, just add it.
                      exprBuffer.append(lookahead);

                      lookahead = tokenizer.nextToken();
                    }
                  }  // end while(!lookahead.equals("}"))

                  if (error != null)
                  {
                    break;  // from inner while loop
                  }
                }

                break;
              }
              catch (java.util.NoSuchElementException ex)
              {
                error = XSLMessages.createMessage(XSLTErrorResources.ER_ILLEGAL_ATTRIBUTE_VALUE, new Object[]{ name, stringedValue }); 
                break;
              }
            }
            case ('}') :
            {
              lookahead = tokenizer.nextToken();

              if (lookahead.equals("}"))
              {

                // Double curlys mean escape to show curly
                buffer.append(lookahead);

                lookahead = null;  // swallow
              }
              else
              {

                // Illegal, I think...
                try
                {
                  handler.warn(XSLTErrorResources.WG_FOUND_CURLYBRACE, null);  //"Found \"}\" but no attribute template open!");
                }
                catch (org.xml.sax.SAXException se)
                {
                  throw new TransformerException(se);
                }

                buffer.append("}");

                // leave the lookahead to be processed by the next round.
              }

              break;
            }
            default :
            {

              // Anything else just add to string.
              buffer.append(t);
            }
            }  // end switch t
          }  // end if length == 1
          else
          {

            // Anything else just add to string.
            buffer.append(t);
          }

          if (null != error)
          {
            try
            {
              handler.warn(XSLTErrorResources.WG_ATTR_TEMPLATE,
                           new Object[]{ error });  //"Attr Template, "+error);
            }
            catch (org.xml.sax.SAXException se)
            {
              throw new TransformerException(se);
            }

            break;
          }
        }  // end while(tokenizer.hasMoreTokens())

        if (buffer.length() > 0)
        {
          m_parts.addElement(new AVTPartSimple(buffer.toString()));
          buffer.setLength(0);
        }
      }
      finally
      {
        StringBufferPool.free(buffer);
        StringBufferPool.free(exprBuffer);
      }
    }  // end else nTokens > 1

    if (null == m_parts && (null == m_simpleString))
    {

      // Error?
      m_simpleString = "";
    }
  }

  /**
   * Get the AVT as the original string.
   *
   * @return The AVT as the original string
   */
  public String getSimpleString()
  {

    if (null != m_simpleString)
    {
      return m_simpleString;
    }
    else if (null != m_parts)
    {
      FastStringBuffer buf = StringBufferPool.get();
      String s;

      try
      {
        buf.setLength(0);

        int n = m_parts.size();

        for (int i = 0; i < n; i++)
        {
          AVTPart part = (AVTPart) m_parts.elementAt(i);

          buf.append(part.getSimpleString());
        }

        s = buf.toString();
      }
      finally
      {
        StringBufferPool.free(buf);
      }

      return s;
    }
    else
    {
      return "";
    }
  }

  /**
   * Evaluate the AVT and return a String.
   *
   * @param xctxt Te XPathContext to use to evaluate this.
   * @param context The current source tree context.
   * @param nsNode The current namespace context (stylesheet tree context).
   * @param NodeList The current Context Node List.
   *
   * @return The AVT evaluated as a string
   *
   * @throws javax.xml.transform.TransformerException
   */
  public String evaluate(
          XPathContext xctxt, int context, org.apache.xml.utils.PrefixResolver nsNode)
            throws javax.xml.transform.TransformerException
  {

    FastStringBuffer buf = StringBufferPool.get();

    try
    {
      if (null != m_simpleString)
      {
        return m_simpleString;
      }
      else if (null != m_parts)
      {
        buf.setLength(0);

        int n = m_parts.size();

        for (int i = 0; i < n; i++)
        {
          AVTPart part = (AVTPart) m_parts.elementAt(i);

          part.evaluate(xctxt, buf, context, nsNode);
        }

        return buf.toString();
      }
      else
      {
        return "";
      }
    }
    finally
    {
      StringBufferPool.free(buf);
    }
  }

  /**
   * Test whether the AVT is insensitive to the context in which
   *  it is being evaluated. This is intended to facilitate
   *  compilation of templates, by allowing simple AVTs to be
   *  converted back into strings.
   *
   *  Currently the only case we recognize is simple strings.
   * ADDED 9/5/2000 to support compilation experiment
   *
   * @return True if the m_simpleString member of this AVT is not null
   */
  public boolean isContextInsensitive()
  {
    return null != m_simpleString;
  }

  /**
   * Tell if this expression or it's subexpressions can traverse outside
   * the current subtree.
   *
   * @return true if traversal outside the context node's subtree can occur.
   */
  public boolean canTraverseOutsideSubtree()
  {

    if (null != m_parts)
    {
      int n = m_parts.size();

      for (int i = 0; i < n; i++)
      {
        AVTPart part = (AVTPart) m_parts.elementAt(i);

        if (part.canTraverseOutsideSubtree())
          return true;
      }
    }

    return 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)
  {
    if (null != m_parts)
    {
      int n = m_parts.size();

      for (int i = 0; i < n; i++)
      {
        AVTPart part = (AVTPart) m_parts.elementAt(i);

        part.fixupVariables(vars, globalsSize);
      }
    }
  }
  
  /**
   * @see XSLTVisitable#callVisitors(XSLTVisitor)
   */
  public void callVisitors(XSLTVisitor visitor)
  {
  	if(visitor.visitAVT(this) && (null != m_parts))
  	{
      int n = m_parts.size();

      for (int i = 0; i < n; i++)
      {
        AVTPart part = (AVTPart) m_parts.elementAt(i);

        part.callVisitors(visitor);
      }  		
  	}
  }


  /**
   * Returns true if this AVT is simple
   */
  public boolean isSimple() {
  	return m_simpleString != null;
  }
}