Caching

The caching class gets initialized as remoteStorage.caching, unless the RemoteStorage instance is created with the option cache: false, disabling caching entirely.

In case your app hasn’t explictly configured caching, the default setting is to cache any documents that have been either created or requested since your app loaded. For offline-capable apps, it usually makes sense to enable full, automatic caching of all documents, which is what enable() will do.

Enabling full caching has several benefits:

  • Speed of access: locally cached data is available to the app a lot faster.

  • Offline mode: when all data is cached, it can also be read when your app starts while being offline.

  • Initial synchronization time: the amount of data your app caches can have a significant impact on its startup time.

Caching can be configured on a per-path basis. When caching is enabled for a folder, it causes all subdirectories to be cached as well.

Caching strategies

For each subtree, you can set the caching strategy to ALL, SEEN (default), and FLUSH.

  • ALL means that once all outgoing changes have been pushed, sync will start retrieving nodes to cache pro-actively. If a local copy exists of everything, it will check on each sync whether the ETag of the root folder changed, and retrieve remote changes if they exist.

  • SEEN does this only for documents and folders that have been either read from or written to at least once since connecting to the current remote backend, plus their parent/ancestor folders up to the root (to make tree-based sync possible).

  • FLUSH will only cache outgoing changes, and forget them as soon as they have been saved to remote successfully.

List of functions

enable(path)

Enable caching for a given path.

Uses caching strategy ALL.

Arguments:

  • path (string) – Path to enable caching for

Example:

remoteStorage.caching.enable('/bookmarks/');
disable(path)

Disable caching for a given path.

Uses caching strategy FLUSH (meaning items are only cached until successfully pushed to the remote).

Arguments:

  • path (string) – Path to disable caching for

Example:

remoteStorage.caching.disable('/bookmarks/');
set(path, strategy)

Configure caching for a given path explicitly.

Not needed when using enable/disable.

Arguments:

  • path (string) – Path to cache

  • strategy ("ALL"|"SEEN"|"FLUSH") – Caching strategy. One of ‘ALL’, ‘SEEN’, or ‘FLUSH’.

Example:

remoteStorage.caching.set('/bookmarks/archive/', 'SEEN');
checkPath(path)

Retrieve caching setting for a given path, or its next parent with a caching strategy set.

Arguments:

  • path (string) – Path to retrieve setting for

Returns:

string – caching strategy for the path

Example:

remoteStorage.caching.checkPath('documents/').then(strategy => {
  console.log(`caching strategy for 'documents/': ${strategy}`));
  // "caching strategy for 'documents/': SEEN"
});
reset()

Reset the state of caching by deleting all caching information.

Example:

remoteStorage.caching.reset();