Bookshelf v7.8: How Hierarchical List Applets Are Rendered

The Siebel Web Engine supports rendering hierarchical list applets. These applets are used to show records that have a hierarchical relationship. These applets are modeled as list applets, and the hierarchy is implemented in the business component by setting the Hierarchy Parent Field attribute. These applets can be shown as a hierarchy in the Base and Edit List modes.

Hierarchical list applets do not need new templates. The icons required to display the hierarchy are added automatically to the first column in the list applet that is mapped to a business component field (Figure 134).

It is also possible to show a hierarchical list applet using a Windows Explorer-like UI (very similar to the tree control). An example of this is the Categories list used to create and manage catalog categories in Siebel eSales.

The icons used for rendering the list applet should be specified in the repository using the HTML Hierarchy Bitmap object named in the HTML Hierarchy Bitmap attribute of the list object. The following bitmaps need to be specified for the HTML Hierarchy Bitmap—Expand Bitmap, Collapse Bitmap, and Space. The other bitmaps (except Arrow Down/Up Bitmap which is used only by tree controls) can be specified to get an applet that resembles the tree applet (which is not specified for hierarchical list applets in the current UI standards).

The hierarchical list applets also let you edit the hierarchy. This is done by adding controls that invoke the following methods on the applet (Table 68).

Table 68. Hierarchical List Applet Methods
Method	Action
Indent	Moves the current record to be a child of its preceding peer record (such as the record above)
Outdent	Moves the current record to be a peer of its parent record
MoveUp	Moves the current record up over its peer record
MoveDown	Moves the current record down over its peer record

When Indent and Outdent methods are invoked on a record, its relation to its child records does not change. The child records are also indented or outdented.

The MoveUp and MoveDown methods are used to position a record to invoke the Indent method. The changes made by the MoveUp and MoveDown methods are temporary; they are not saved to the database.

For a better appearance, the number of columns displayed in a hierarchical list applet should be small since the width of the column with the expand/collapse controls expand as a user navigates down the hierarchy. Similarly, the column with the expand/collapse controls should be a column with short field values.