workbox-background-sync

Summary

Types
BackgroundSyncPlugin
Queue
QueueOptions
QueueStore
StorableRequest

Types

BackgroundSyncPlugin

A class implementing the fetchDidFail lifecycle callback. This makes it easier to add failed requests to a background sync Queue.

Properties

constructor
function
The constructor function looks like: (name: string, options?: QueueOptions) => {...}
- name
  string
  See the workbox-background-sync.Queue documentation for parameter details.
- options
  QueueOptions optional
- returns
  BackgroundSyncPlugin

Queue

A class to manage storing failed requests in IndexedDB and retrying them later. All parts of the storing and replaying process are observable via callbacks.

Properties

constructor
function
Creates an instance of Queue with the given options
The constructor function looks like: (name: string, options?: QueueOptions) => {...}
- name
  string
  The unique name for this queue. This name must be unique as it's used to register sync events and store requests in IndexedDB specific to this instance. An error will be thrown if a duplicate name is detected.
- options
  QueueOptions optional
- returns
  Queue
name
string
getAll
function
Returns all the entries that have not expired (per maxRetentionTime). Any expired entries are removed from the queue.
The getAll function looks like: () => {...}
- returns
  Promise<QueueEntry[]>
popRequest
function
Removes and returns the last request in the queue (along with its timestamp and any metadata). The returned object takes the form: {request, timestamp, metadata}.
The popRequest function looks like: () => {...}
- returns
  Promise<QueueEntry>
pushRequest
function
Stores the passed request in IndexedDB (with its timestamp and any metadata) at the end of the queue.
The pushRequest function looks like: (entry: QueueEntry) => {...}
- entry
  QueueEntry
- returns
  Promise<void>
registerSync
function
Registers a sync event with a tag unique to this instance.
The registerSync function looks like: () => {...}
- returns
  Promise<void>
replayRequests
function
Loops through each request in the queue and attempts to re-fetch it. If any request fails to re-fetch, it's put back in the same position in the queue (which registers a retry for the next sync event).
The replayRequests function looks like: () => {...}
- returns
  Promise<void>
shiftRequest
function
Removes and returns the first request in the queue (along with its timestamp and any metadata). The returned object takes the form: {request, timestamp, metadata}.
The shiftRequest function looks like: () => {...}
- returns
  Promise<QueueEntry>
size
function
Returns the number of entries present in the queue. Note that expired entries (per maxRetentionTime) are also included in this count.
The size function looks like: () => {...}
- returns
  Promise<number>
unshiftRequest
function
Stores the passed request in IndexedDB (with its timestamp and any metadata) at the beginning of the queue.
The unshiftRequest function looks like: (entry: QueueEntry) => {...}
- entry
  QueueEntry
- returns
  Promise<void>

QueueOptions

Properties

forceSyncFallback
boolean optional
maxRetentionTime
number optional
onSync
OnSyncCallback optional

QueueStore

A class to manage storing requests from a Queue in IndexedDB, indexed by their queue name for easier access.

Most developers will not need to access this class directly; it is exposed for advanced use cases.

Properties

constructor
function
Associates this instance with a Queue instance, so entries added can be identified by their queue name.
The constructor function looks like: (queueName: string) => {...}
- queueName
  string
- returns
  QueueStore
deleteEntry
function
Deletes the entry for the given ID.
WARNING: this method does not ensure the deleted entry belongs to this queue (i.e. matches the queueName). But this limitation is acceptable as this class is not publicly exposed. An additional check would make this method slower than it needs to be.
The deleteEntry function looks like: (id: number) => {...}
- id
  number
- returns
  Promise<void>
getAll
function
Returns all entries in the store matching the queueName.
The getAll function looks like: () => {...}
- returns
  Promise<QueueStoreEntry[]>
popEntry
function
Removes and returns the last entry in the queue matching the queueName.
The popEntry function looks like: () => {...}
- returns
  Promise<QueueStoreEntry>
pushEntry
function
Append an entry last in the queue.
The pushEntry function looks like: (entry: UnidentifiedQueueStoreEntry) => {...}
- entry
  UnidentifiedQueueStoreEntry
- returns
  Promise<void>
shiftEntry
function
Removes and returns the first entry in the queue matching the queueName.
The shiftEntry function looks like: () => {...}
- returns
  Promise<QueueStoreEntry>
size
function
Returns the number of entries in the store matching the queueName.
The size function looks like: () => {...}
- returns
  Promise<number>
unshiftEntry
function
Prepend an entry first in the queue.
The unshiftEntry function looks like: (entry: UnidentifiedQueueStoreEntry) => {...}
- entry
  UnidentifiedQueueStoreEntry
- returns
  Promise<void>

StorableRequest

A class to make it easier to serialize and de-serialize requests so they can be stored in IndexedDB.

Most developers will not need to access this class directly; it is exposed for advanced use cases.

Properties

constructor
function
Accepts an object of request data that can be used to construct a Request but can also be stored in IndexedDB.
The constructor function looks like: (requestData: RequestData) => {...}
- requestData
  RequestData
  An object of request data that includes the url plus any relevant properties of [requestInit]https://fetch.spec.whatwg.org/#requestinit.
- returns
  StorableRequest
clone
function
Creates and returns a deep clone of the instance.
The clone function looks like: () => {...}
- returns
  StorableRequest
toObject
function
Returns a deep clone of the instances _requestData object.
The toObject function looks like: () => {...}
- returns
  RequestData
toRequest
function
Converts this instance to a Request.
The toRequest function looks like: () => {...}
- returns
  Request
fromRequest
function
Converts a Request object to a plain object that can be structured cloned or JSON-stringified.
The fromRequest function looks like: (request: Request) => {...}
- request
  Request
- returns
  Promise<StorableRequest>