# <netui-data:expressionColumn> Tag

A column that can use data binding expressions to determine the value of a data cell.

## Syntax

<netui-data:expressionColumn
[styleClassPrefix="string_styleClassPrefix"]
title="string_title"
value="string_or_expression_value" />

## Description

A column that can use data binding expressions to determine the value of a data cell. The expression column enables combining data from different fields of the current data item or even from different expression contexts into a value for the cell. The <netui-data:expressionColumn> tag cannot make a method call to determine the value of a data cell. An expression column is not sortable or filterable.

## Attributes

styleClassPrefix | The style class prefix used to make the style class name in the header, data, and footer cells. The `styleClassPrefix` will be concatinated with a suffix to create style class names that are rendered inside of the <td> tags for each cell in this column. Assuming the value of this attribute is `foo`, the style class names rendered for each part of the column are shown in the table below.
Column Region | Style class
Header | foo-td-header
Data | foo-td-data
Footer | foo-td-footer
Required | Supports runtime expression evaluation | Data bindable
No | No | No
title | The text to render in the column header.
Required | Supports runtime expression evaluation | Data bindable
Yes | No | No
value | The value may contain an expression(s) that will be evaluated before the data for each item in the <netui-data:grid>'s data set is rendered. The databinding expression `{container.item}` may be used to access the current data item that is being rendered.
Required | Supports runtime expression evaluation | Data bindable
Yes | No | Yes

## Sample

Given a data item that has a `lastName` field and a `firstName` field, the following would render these together in a single cell:

        <netui-data:expessionColumn value="{container.item.lastName},
             {container.item.firstName}"
             title="Last Name, First Name"
             />

## Sample Code

[BEA_HOME]/weblogic81/samples/workshop/SamplesApp/WebApp/tagSamples/netui_databinding/grid/grid.jsp

## Related Topics