Selective Overlays

Selective overlays provide a more granular mechanism for overriding template content: they allow you to specify exactly which parts of a template you want to override – you aren't limited to overriding entire top-level areas.

A selective overlay does not have the same top level areas as an ordinary template. Instead it has a single top-level area called Overlay config area. In this area you can add one or more Area overlay and/or Group overlay groups:

  • An Area overlay group contains an overlay for a named top-level area (so an area overlay doesn't in fact offer any more granularity than an inheritance overlay). It has a Referenced area option that you must use to specify the area that it is to replace. The option only allows you to select top-level areas.

    An area overlay cannot be used to replace the top-level area of a master template. Neither can it be used to replace the top-level area of an inline template.

  • A Group overlay group contains an overlay for a named group. You can therefore use it to replace any part of a template, not just top-level components. It has a Referenced group option that you must use to specify the group that it is to replace.