Rx.Observable.fromPromise(promise)
Converts a Promises/A+ spec compliant Promise and/or ES2015 compliant Promise or a factory function which returns said Promise to an Observable sequence.
Arguments
promise|Function
:Promise
- Promises/A+ spec compliant Promise to an Observable sequence or a function which returns a Promise.
Returns
Observable
: An Observable sequence which wraps the existing promise success and failure.
Example
// Create a factory function which returns a promise
var promiseFn = function () { return Promise.resolve(42); };
var source = Rx.Observable.fromPromise(promiseFn);
var subscription = source.subscribe(
function (x) {
console.log('Next: %s', x);
},
function (err) {
console.log('Error: %s', err);
},
function () {
console.log('Completed');
});
// Create a promise which resolves 42
var promise1 = Promise.resolve(42)
var source1 = Rx.Observable.fromPromise(promise1);
var subscription1 = source1.subscribe(
function (x) {
console.log('Next: %s', x);
},
function (err) {
console.log('Error: %s', err);
},
function () {
console.log('Completed');
});
// => Next: 42
// => Completed
// Create a promise which rejects with an error
var promise2 = Promise.reject(new Error('reason'));
var source2 = Rx.Observable.fromPromise(promise2);
var subscription2 = source2.subscribe(
function (x) {
console.log('Next: %s', x);
},
function (err) {
console.log('Error: %s', err);
},
function () {
console.log('Completed');
});
// => Error: Error: reject
Location
File:
Dist:
Prerequisites:
- If using
rx.async.js
|rx.async.compat.js
rx.lite.js
|rx.lite.compat.js
NPM Packages:
NuGet Packages:
Unit Tests: