A Custom Entity Demo for Backdrop CMS

This repo contains 4 modules that show how to develop custom entities in Backdrop. All 4 modules define a student entity, and get progressively more complex.

Important:

1. Don't use these modules on production sites
2. Fully uninstall each module before installing the next one provided here. Otherwise you'll get a "white screen of death" and your site may be be unreachable, since the modules use some of the same functions and create the same table when enabled
3. If you create Student entities, be sure to delete them before uninstalling the module
4. If you add fields to your Student entity, be sure to fully delete the fields and run Cron before uninstalling. There is a bug in Backdrop's core that prevents the deletion of field data when uninstalling an entity.

Demo 1 (ed1.module)

This demo shows that basic setup to define a new custom entity.

1. The student entity is not fieldable
2. The first part of the module is enough for core to recognize the entity. You can use entity_create, entity_load etc. to operate on the entity
3. The second part of the module file provides some basic UI and permissions:
   • Forms to create and edit students
   • A basic table of existing students (available at path student)
   • Operation links to create, view, edit and delete students

Demo 2 (ed2.module)

This demo provides a fieldable entity, and adds basic handling of bundles.

1. Two bundles are hard-coded as part of the entity definition (basic_student and adult_student)
2. Provides a listing of the bundles at admin/student-bundle
3. A basic function to load bundle information, which is made available to the Field API
4. Allows Field API to provide "Manage fields" and "Manage display" tabs for each bundle
5. All forms and table from ed1 still available at path student

Demo 3 (ed3.module)

This demo provides dynamic bundle creation capabilities. It also places the admin functions within the Structure admin menu. Basic bundle information (label and machine name) are saved as config files.

1. Bundles can be dynamically created at admin/structure/student-bundle
2. All functionality of Demo 2 are available
3. Defines "extra fields" (aka pseudo fields) for the entity properties. This allows the admin to move those fields around or to hide them in the Manage display UI

Demo 4 (ed4.module)

This demo depends on Entity Plus. It replaces the entity controller for EntityPlusController to provide seamless Views integration, tokens, Entity Metadata Wrappers and more. Token support is provided by enabling Entity Tokens.

1. The list of Students is now a View. All properties defined in hook_schema are available as Views fields and filters
2. Student entities can be used as contexts in Layouts. Also, it's possible to override the path student/%student to use a different layout to display student entities (e.g. by placing some of its fields in a different block)
3. All functionality from ed4 is available

Feel free to fork and play around. Issues and PRs are also welcome.