Implicit ESI controls vs explicit ESI controls

Explicit controls are those that you add explicitly, for example by inserting an extra query. Explicit controls are inserted with esi-insert-control().

Implicit controls are controls that are created spontaneously in the run-time environment:

• Column displays (see below)
• Embedded details
• Groups
• Windows (or shells)
• Grid Boxes
• Columns that are created by extra queries

To be able to set properties on implicit controls, you must first use the esi-add-component() action to register these controls.

For column displays, esi-add-component() is only required if the underlying query has been changed. Such components are best registered at base-table level, all classes below that will then know of their existence.