Deferred objeccts and their promises allow us to react to the conpletion of long-running tasks with a convenient syntax.
目录
Object creation
| Function | Description |
|---|---|
| $.Deferred([setupFunction]) | Returns a new deferred object. |
| $.when(deferreds) | Returns a promise object to be resolved when the given deferred objecs are resolved. |
Methods of deferred objects
| Method | Description |
|---|---|
| .resolve([args]) | Sets the state of the object to resolved. |
| .resolveWith(context, [args]) | Sets the state of the objec to resolved while making the keyword this refer to context within callbacks. |
| .rejectWith([args]) | Sets the state of the object to rejected. |
| .rejectWith(context, [args]) | Sets the state of the object to rejected while making the keyword this refer to context within callbacks. |
| .notify([args]) | Executes any progress callbacks. |
| .notifyWith(context, [args]) | Executes any progress callback while making the keyword this refer to context. |
| .promise([target]) | Returns a promise object corresponding to this deferred object. |
Methods of promise objects
| Method | Description |
|---|---|
| .done(callback) | Executes callback when the object is resolved. |
| .fail(callback) | Executes callback when the object is rejected. |
| .always(callback) | Executes callback when the object is resolved or rejected. |
| .then(doneCallbacks, failCallbacks) | Executes doneCallbacks when the object is resolved, or failCallbacks when the object is rejected. |
| .progress(callback) | Executes callback each time the object receives a progress notification. |
| .isRejected() | Returns true if the object has been rejected. |
| .isResolved() | Returns true if the object has been resolved. |
| .state() | Returns ‘pending’, ‘resolved’, or ‘rejected’ depending on the current state. |
| .pipe([doneFilter], [failFilter]) | Returns a new promise object which is resolved when the original promise is, optionally after filtering the object’s status through a function. |