Java Code Examples for org.apache.xpath.Expression#execute()

/**
 * Execute the function.  The function must return
 * a valid object.
 * @param xctxt The current execution context.
 * @return A valid XObject.
 *
 * @throws javax.xml.transform.TransformerException
 */
public XObject execute(XPathContext xctxt)
        throws javax.xml.transform.TransformerException
{
  if (xctxt.isSecureProcessing())
    throw new javax.xml.transform.TransformerException(
      XPATHMessages.createXPATHMessage(
        XPATHErrorResources.ER_EXTENSION_FUNCTION_CANNOT_BE_INVOKED,
        new Object[] {toString()}));
    
  XObject result;
  Vector argVec = new Vector();
  int nArgs = m_argVec.size();

  for (int i = 0; i < nArgs; i++)
  {
    Expression arg = (Expression) m_argVec.elementAt(i);
    
    XObject xobj = arg.execute(xctxt);
    /*
     * Should cache the arguments for func:function
     */
    xobj.allowDetachToRelease(false); 
    argVec.addElement(xobj);
  }
  //dml
  ExtensionsProvider extProvider = (ExtensionsProvider)xctxt.getOwnerObject();
  Object val = extProvider.extFunction(this, argVec);

  if (null != val)
  {
    result = XObject.create(val, xctxt);
  }
  else
  {
    result = new XNull();
  }

  return result;
}
 

/**
 * Execute the expression.  Meant for reuse by other FilterExpr iterators 
 * that are not derived from this object.
 */
public static XNodeSet executeFilterExpr(int context, XPathContext xctxt, 
												PrefixResolver prefixResolver,
												boolean isTopLevel,
												int stackFrame,
												Expression expr )
  throws org.apache.xml.utils.WrappedRuntimeException
{
  PrefixResolver savedResolver = xctxt.getNamespaceContext();
  XNodeSet result = null;

  try
  {
    xctxt.pushCurrentNode(context);
    xctxt.setNamespaceContext(prefixResolver);

    // The setRoot operation can take place with a reset operation, 
    // and so we may not be in the context of LocPathIterator#nextNode, 
    // so we have to set up the variable context, execute the expression, 
    // and then restore the variable context.

    if (isTopLevel)
    {
      // System.out.println("calling m_expr.execute(getXPathContext())");
      VariableStack vars = xctxt.getVarStack();

      // These three statements need to be combined into one operation.
      int savedStart = vars.getStackFrame();
      vars.setStackFrame(stackFrame);

      result = (org.apache.xpath.objects.XNodeSet) expr.execute(xctxt);
      result.setShouldCacheNodes(true);

      // These two statements need to be combined into one operation.
      vars.setStackFrame(savedStart);
    }
    else
        result = (org.apache.xpath.objects.XNodeSet) expr.execute(xctxt);

  }
  catch (javax.xml.transform.TransformerException se)
  {

    // TODO: Fix...
    throw new org.apache.xml.utils.WrappedRuntimeException(se);
  }
  finally
  {
    xctxt.popCurrentNode();
    xctxt.setNamespaceContext(savedResolver);
  }
  return result;
}
 

/**
 * For support of literal objects in xpaths.
 *
 * @param xctxt The XPath execution context.
 *
 * @return This object.
 *
 * @throws javax.xml.transform.TransformerException
 */
public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
{
	Expression expr = ((ElemVariable)m_obj).getSelect().getExpression();
  XObject xobj = expr.execute(xctxt);
  xobj.allowDetachToRelease(false);
  return xobj;
}