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6ea1c1a Apr 26, 2016
@mattpodwysocki @L8D @mmv @jca02266 @mixed
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Rx.Observable.fromCallback(func, [context], [selector])

Converts a callback function to an observable sequence.

Arguments

  1. func (Function): Function with a callback as the last parameter to convert to an Observable sequence.
  2. [context] (Any): The context for the func parameter to be executed. If not specified, defaults to undefined.
  3. [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:

NPM Packages:

NuGet Packages:

Unit Tests: