Bug 189706 Enhance computed column aggregation function handling in UI.
Due to the issue discussed in 189705, current computed column aggregation builder in data set editor has bugs to extend: 1.When new a computed column, the aggregation argument field cannot be correctly set. 2.The argument field cannot be correct grayed out when user select a aggregation function without arguments 3.The available aggregation function list is incomprehensive 4.Some aggregation function cannot be set to model(say, weightedAve).
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/expression/ExpressionProcessor.java
}
		calculate( helper );
	}
	/**
	 * 
	 * @param list
	 * @return
	 * @throws DataException
	 */
	public boolean hasAggregateExpr( List list )
			throws DataException
	{
		boolean hasAggregate = false;
		MultiPassExpressionCompiler helper = new MultiPassExpressionCompiler( rsPopulator,
				baseQuery,
				dataset.getScriptScope( ),
				availableAggrList );
		helper.setDataSetMode( isDataSetMode );
		IBaseExpression baseExpression = null;
		for ( int i = 0; i < list.size( ); i++ )
		{
			baseExpression = (IBaseExpression) list.get( i );
			compileBaseExpression( baseExpression, helper );
		}
		hasAggregate = helper.getAggregateStatus( );
		clear( );
		return hasAggregate;
	}
	/**
	 *