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
|
### `Rx.Observable.start(func, [context], [scheduler])`
[Ⓢ](https://github.com/Reactive-Extensions/RxJS/blob/master/src/core/linq/observable/start.js "View in source")
Invokes the specified function asynchronously on the specified scheduler, surfacing the result through an observable sequence.
### Arguments
1. `func` *(`Function`)*: Function to run asynchronously.
2. `[context]` *(`Any`)*: The context for the func parameter to be executed. If not specified, defaults to undefined.
3. `[scheduler=Rx.Scheduler.timeout]` *(`Scheduler`)*: Scheduler to run the function on. If not specified, defaults to Scheduler.timeout.
#### Returns
*(`Observable`)*: An observable sequence exposing the function's result value, or an exception.
#### Example
```js
var context = { value: 42 };
var source = Rx.Observable.start(
function () {
return this.value;
},
context,
Rx.Scheduler.timeout
);
var subscription = source.subscribe(
function (x) {
console.log('Next: ' + x);
},
function (err) {
console.log('Error: ' + err);
},
function () {
console.log('Completed');
});
// => Next: 42
// => Completed
```
### Location
File:
- [/src/core/linq/observable/start.js](https://github.com/Reactive-Extensions/RxJS/blob/master/src/core/linq/observable/start.js)
Dist:
- [`rx.async.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.async.js)
- [`rx.async.compat.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.async.compat.js)
- [`rx.lite.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.lite.js)
- [`rx.lite.compat.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.lite.compat.js)
Prerequisites:
- If using rx.async.js | rx.async.compat.js
- [`rx.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.js) | [`rx.compat.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.compat.js)
- [`rx.binding.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.binding.js)
NPM Packages:
- [`rx`](https://www.npmjs.org/package/rx)
NuGet Packages:
- [`RxJS-All`](http://www.nuget.org/packages/RxJS-All)
- [`RxJS-Async`](http://www.nuget.org/packages/RxJS-Async)
- [`RxJS-Lite`](http://www.nuget.org/packages/RxJS-Lite/)
Unit Tests:
- [/tests/observable/start.js](https://github.com/Reactive-Extensions/RxJS/blob/master/tests/observable/start.js)
|
