Rx.Observable.fromCallback(func, [context], [selector])
Converts a callback function to an observable sequence.
Arguments
func
(Function
): Function with a callback as the last parameter to convert to an Observable sequence.[context]
(Any
): The context for the func parameter to be executed. If not specified, defaults to undefined.[selector]
(Function
): A selector which takes the arguments from the callback to produce a single item to yield on next.
Returns
(Function
): A function, when executed with the required parameters minus the callback, produces an Observable sequence with a single value of the arguments to the callback as an array if no selector given, else the object created by the selector function.
Example
var fs = require('fs'),
Rx = require('rx');
// Wrap fs.exists
var exists = Rx.Observable.fromCallback(fs.exists);
// Check if file.txt exists
var source = exists('file.txt');
var subscription = source.subscribe(
function (x) {
console.log('Next: ' + x);
},
function (err) {
console.log('Error: ' + err);
},
function () {
console.log('Completed');
});
// => Next: true
// => Completed
Location
File:
Dist:
Prerequisites:
- If using
rx.async.js
|rx.async.compat.js
NPM Packages:
NuGet Packages:
Unit Tests: