Nextcloud filesystem API
High level guide to using the Nextcloud filesystem API.
Because users can choose their storage backend, the filesystem should be accessed by using the appropriate filesystem classes. For a simplified filesystem for app specific data see IAppData
The “Node API” is the primary api for apps to access the Nextcloud filesystem, each item in the filesystem is represented as either a File or Folder node with each node providing access to the relevant filesystem information and actions for the node.
Access to the filesystem is provided by the
IRootFolder which can be injected into your class.
From the root folder you can either access a user’s home folder or access a file or folder by its absolute path.
For more details on the specific methods provided by file and folder nodes see the method documentation from the
Writing to a file
All methods return a Folder object on which files and folders can be accessed, or filesystem operations can be performed relatively to their root. For instance for writing to file:nextcloud/data/myfile.txt you should get the root folder and use:
Reading from a file
Files and folders can also be accessed by id, by calling the getById method on the folder.
Direct storage access
While it should be generally avoided in favor of the higher level apis, sometimes an app needs to talk directly to the storage implementation of it’s metadata cache.
You can get access to the underlying storage of a file or folder by calling
getStorage on the node or first getting
the mountpoint by calling
getMountPoint and getting the storage from there.
Once you have the storage instance you can use the storage api from
OCP\Files\Storage\IStorage, note however that
all paths used in the storage api are internal to the storage, the
IMountPoint returned from
methods for translating between absolute filesystem paths and internal storage paths.
If you need to query the cached metadata directory you can get the
OCP\Files\Cache\ICache from the storage by calling
Implementing a storage
The recommended way for implementing a storage backend is by sub-classing
OC\Files\Storage\Common which provides
fallback implementations for various methods, reducing the amount of work required to implement the full storage api.
Note however that various of these fallback implementations are likely to be significantly less efficient than an
implementation of the method optimized for the abilities of the storage backend.
Adding mounts to the filesystem
The recommended way of adding your own mounts to the filesystem from an app is implementing
and registering the provider using
Once registered, your provider will be called every time the filesystem is being setup for a user and your mount provider can return a list of mounts to add for that user.