I create a new view mode for an entity type, either:
- by installing a module that defines one, such as diff
- in custom code with hook_entity_info()
- with a contrib module that exposes an admin UI, such as Display Suite or Custom View Modes
I then save the form at admin/structure/types/manage/article/display. The variable field_bundle_settings_node__article contains details of the view modes, like this:
Array
(
[view_modes] => Array
(
[teaser] => Array
(
[custom_settings] => 1
)
[full] => Array
(
[custom_settings] =>
)
[rss] => Array
(
[custom_settings] =>
)
[article_image] => Array
(
[custom_settings] => 1
)
[diff_standard] => Array
(
[custom_settings] =>
)
)
[extra_fields] => Array
(
[form] => Array
(
[title] => Array
(
[weight] => 0
)
)
[display] => Array
(
)
)
)If I later on remove my new view mode, its settings remain in this variable, and there seems to be no way of removing them (apart from hacking the {variable} table and editing the serialized array!)
Note: this is probably not relevant on D8 due to #1953528: Move 'view modes' part out of field_bundle_settings().