blob: 16aa3429f737ecf999a6b67c914225a2f2cbfad4 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
/**
* Copyright (c) 2013-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
* @providesModule Deferred
* @typechecks
* @flow
*/
/**
* Deferred provides a Promise-like API that exposes methods to resolve and
* reject the Promise. It is most useful when converting non-Promise code to use
* Promises.
*
* If you want to export the Promise without exposing access to the resolve and
* reject methods, you should export `getPromise` which returns a Promise with
* the same semantics excluding those methods.
*/
class Deferred<Tvalue, Treason> {
_settled: boolean;
_promise: Promise<any>;
_resolve: (value: Tvalue) => void;
_reject: (reason: Treason) => void;
constructor() {
this._settled = false;
this._promise = new Promise((resolve, reject) => {
this._resolve = (resolve: any);
this._reject = (reject: any);
});
}
getPromise(): Promise<any> {
return this._promise;
}
resolve(value: Tvalue): void {
this._settled = true;
this._resolve(value);
}
reject(reason: Treason): void {
this._settled = true;
this._reject(reason);
}
catch(onReject?: ?(error: any) => mixed): Promise<any> {
return Promise.prototype.catch.apply(this._promise, arguments);
}
then(onFulfill?: ?(value: any) => mixed, onReject?: ?(error: any) => mixed): Promise<any> {
return Promise.prototype.then.apply(this._promise, arguments);
}
done(onFulfill?: ?(value: any) => mixed, onReject?: ?(error: any) => mixed): void {
// Embed the polyfill for the non-standard Promise.prototype.done so that
// users of the open source fbjs don't need a custom lib for Promise
const promise = arguments.length ? this._promise.then.apply(this._promise, arguments) : this._promise;
promise.then(undefined, function (err) {
setTimeout(function () {
throw err;
}, 0);
});
}
isSettled(): boolean {
return this._settled;
}
}
module.exports = Deferred;
|
