A multiple-selection component allows a user to make one or more selections
from a list of values. The user's selections are stored in a PageHandler array
data area. Check box groups and multiple-select list boxes are multiple-selection
JavaServer Faces components.
A binding is a relationship between the component and a data area. The
data area must be declared in the PageHandler before you can bind a component
to it. A multiple-selection component needs two different kinds of bindings:
- A binding to one or more data areas that contain the values from which
the user can make a selection
- A binding to an array data area that will receive the user's selections
To bind a JavaServer Faces multiple-selection component to existing EGL
PageHandler data areas, do as follows:
- Open a Faces JSP file in the Page Designer. If you do not have a JSP file
open, double-click on the JSP file in the Project Explorer. The JSP opens
in the Page Designer. Click the Design tab to access
the Design view.
- From the Window menu, select Show
View > Other >Basic > Palette.
- In the Palette view, click the Faces Components drawer
to display the Faces Components object types.
- Drag a multiple-selection component from the palette to the JSP. The component
object is placed on the JSP.
- To bind the component to one or more PageHandler data areas that contain
the values you want to display to the user, do one of the following procedures:
- You can bind the component to individual PageHandler data areas, each
of which contains one list item. Perform the following procedure for each
data area:
- Select the object component on the JSP.
- In the Properties view, click Add Choice. The
Name and Value fields are populated with default values.
- Click the Name field, then type the text that
you want to display to the user.
- Click the Value field, then click the button
next to the Value field. Select an individual data
area from the Select Page Data Object list and click OK.
This data area holds the value that will be moved to the receiving data area.
- You can bind the component to a PageHandler array data area that contains
the values you want to display to the user. Perform the following procedure
to bind the component to an array data area:
- Select the object component on the JSP.
- In the Properties view, click Add Set of Choices.
The Name and Value fields are populated with default values.
- Click the Value field, then click the button
next to the Value field. Select an array data area
from the Select Page Data Object list and click OK.
The values in the array data area are the values that will be displayed to
the user. The properties described later determine whether the values in the
array data area or their equivalent index values will be moved to the receiving
data area.
- If you are using an array data area to supply the values displayed to
the user, you must define the receiving data area with two properties: selectFromListItem and selectType. The selectFromListItem property points to the array that holds
the list items. The selectType property indicates whether the receiving data
area is to be populated with a text value or an index value. Examples of receiving
data areas are as follows:
colorSelected char(10)
{selectFromListItem = "colorsArray",
selectType = value};
colorSelectIdx smallInt
{selectFromListItem = "colorsArray",
selectType = index};
- To bind the component to a PageHandler array data area that
will receive the user's selections, do as follows:
- Select the component object on the JSP
- Click the button next to the Value field of
the Properties view
- Select a data area from the Select Page Data Object list
- Click OK