API reference

PHP public API

The public API is contained in the OCP namespace. See the OCP API reference for further details.

The API is split into two categories. Those are indicated by attributes.

Consumable, Listenable and Catchable

Interfaces, Enums and classes that have the OCP\AppFramework\Attribute\Consumable attribute, must only be consumed by apps and can not be implemented by apps themselves. This means the server side can extend the interface with new methods or reduce returned types of existing methods without it being consider an API break. However argument types of existing methods can not be reduced. Same rules apply to OCP\EventsDispatcher\Event that have the OCP\AppFramework\Attribute\Listenable attribute and Exception with the OCP\AppFramework\Attribute\Catchable attribute.

Implementable, Dispatchable and Throwable

Interfaces, Enums and classes that have the OCP\AppFramework\Attribute\Implementable attribute, can be implemented by apps. This means the server side can not extend the interface with new methods or reduce returned types of existing methods without it being consider an API break. However argument types of existing methods can be reduced. Same rules apply to OCP\EventsDispatcher\Event that have the OCP\AppFramework\Attribute\Dispatchable attribute and Exception with the OCP\AppFramework\Attribute\Throwable attribute.

ExceptionalImplementable

Despite not being implementable for all apps, some interfaces can have the OCP\AppFramework\Attribute\ExceptionalImplementable attribute indicating that they are implementable by a single app (or multiple). In those cases the general OCP\AppFramework\Attribute\Consumable rules apply, but the app maintainers or repository of named exceptions have to be informed during the process of a pull request, leaving them enough time to align with the upcoming change.

PHP unstable API

To avoid releasing incomplete public API, it is possible to release a first version of the future API in the NCU namespace, following these rules:

Files are located in /lib/unstable/
Code quality, comments, tests and psalm check are expected to be identical to the OCP namespace.
Classes must be tag as @experimental, including the current version of Nextcloud.
Tag @since must not be used in the NCU namespace.
Code from the OCP namespace must never mention anything coming from the NCU namespace. It can not require it as an argument, constant or return something from NCU.
An API can only live in this unstable namespace for one major release.
During this testing phase, the code and the API can be modified/restructured without limitation.
API within the testing namespace must have up-to-date documentation.
If accepted, the API will be copied to the OCP public namespace.
Once tested, the version from the NCU namespace will be marked as deprecated.
Deprecated API from the NCU namespace are kept for 2 major releases.