Bug 145022 Provide a utility method to help GUI enhance aggregate on.
DtE will provide a method hasAggregation(String expression) in org.eclipse.birt.core.data.ExpressionUtil, and the return value will be true when the expression is a valid JS expression and it has aggregation defined.
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/ExpressionParserUtility.java
return;
			}
			compileComplexExpr( refNode, tree, columnExprList );
			return;
		}
		else
			compileSimpleColumnRefExpr( refNode, rowName, columnExprList );
	}
	/**
	 * compile simple column ref expression
	 * 
	 * @param refNode
	 * @param rowName
	 * @param columnExprList
	 */
	private void compileSimpleColumnRefExpr( Node refNode, Node rowName,
			List columnExprList )
	{
		String str = rowName.getString( );
		assert ( str != null );
		if ( !str.equals( ROW_INDICATOR ) )
			return;
		Node rowColumn = rowName.getNext( );
		assert ( rowColumn != null );
		if ( refNode.getType( ) == Token.GETPROP
				&& rowColumn.getType( ) == Token.STRING )
		{
			int outer_count = 0;
			if ( "__rownum".equals( rowColumn.getString( ) )
					|| "0".equals( rowColumn.getString( ) ) )