Template Sizing Within Tables

[Context: HL Kit … Basic Concepts and Terminology … Manipulation of Visual Elements … Working With Tables]

Template Sizing and Dimensions

Templates are normally sized and positioned either by the layout that contains them or by the template itself. However, templates used within tables are handled a bit differently.

First of all, the positioning of a template within a table is fixed. The table has complete control over the positioning of each template within it.

Secondly, the table dictates the width of the template. Table templates are always sized to span the full width of the table that contains them. The template contents do not need to be positioned to utilize the full width, but the template itself is always sized to that width.

Only the height of a template is controlled by the template when within a table. Most tables have fixed-height items, where the height of each item is always the same. For these tables, the template is sized without any specific item before the table itself is sized. Since no actual item is provided, the template cannot base its height on the contents of the item. It must instead determine its size on general characteristics, such as font heights and other such information. Any attempt to set the height to a different in subsequent invocations of the Position script are ignored.

The exception to this is variable-height tables, which are only supported for printed output. Within such tables, each template has its height re-calculated for every item that is output.

The Position script of the template is invoked separately for each individual item being displayed. It is also invoked once when the table sizing process is initiated. During this initial sizing, you can use the "issizing" target reference to detect the state. When initial sizing is being performed, the template need only calculate its height and can bail out without doing anything else. Since any other script logic is going to be thrown away during the sizing operation, there is no need to perform it.