Bug 118780 Set alias for columns in data set but in expression builder still shows the old columns name when select the dataset.
Description: Set alias for columns in data set but in expression builder still shows the old columns name when select the dataset. Steps to reproduce: 1. New a datasource and a dataset 2. Set alias of the first column in the dataset to "column1". 3. Insert a data item and bind it to dataset. 4. In the expression builder, select the dataset and double click the first column name. Expected result: According to scr #78193 in tracker, the first column in expression build should use alias name instead of original name. Actual result: The original name of the first column was listed in the below of expression builder but the alias name appeared above as row["column1"] after double click the original name.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ExpressionProvider.java
else if ( element instanceof DataSetItemModel
				|| element instanceof ParameterHandle )
		{
			return DEUtil.getExpression( element );
		}
		return null;
	}
	private static Image getIconImage( String id )
	{
		return ReportPlatformUIImages.getImage( id );
	}
	private List getClassList( boolean isNative )
	{
		List list = DesignEngine.getMetaDataDictionary( ).getClasses( );
		ArrayList resultList = new ArrayList( );
		for ( Iterator iter = list.iterator( ); iter.hasNext( ); )
		{
			IClassInfo classInfo = (IClassInfo) iter.next( );
			if ( classInfo.isNative( ) == isNative )
			{
				resultList.add( classInfo );
			}
		}
		return resultList;
	}
	/**
	 * Adds a filter for this expression builder.
	 * 
	 * @param filter
	 *            the filter to add