Rx.Observable.fromEventPattern(addHandler, [removeHandler], [selector])
Creates an observable sequence by using the addHandler and removeHandler functions to add and remove the handlers, with an optional selector function to project the event arguments.
Arguments
addHandler
(Function
): The DOMElement, NodeList or EventEmitter to attach a listener.[removeHandler]
(Function
): The optional function to remove a handler from an emitter.[selector]
(Function
): A selector which takes the arguments from the event handler to produce a single item to yield on next.
Returns
(Observable
): An observable sequence of events from the specified element and the specified event.
Example
Wrapping an event from jQuery
var input = $('#input');
var source = Rx.Observable.fromEventPattern(
function add (h) {
input.bind('click', h);
},
function remove (h) {
input.unbind('click', h);
}
);
var subscription = source.subscribe(
function (x) {
console.log('Next: Clicked!');
},
function (err) {
console.log('Error: %s', err);
},
function () {
console.log('Completed');
});
input.trigger('click');
// => Next: Clicked!
Wrapping an event from the Dojo Toolkit
require(['dojo/on', 'dojo/dom', 'rx', 'rx.async', 'rx.binding'], function (on, dom, rx) {
var input = dom.byId('input');
var source = Rx.Observable.fromEventPattern(
function add (h) {
return on(input, 'click', h);
},
function remove (_, signal) {
signal.remove();
}
);
var subscription = source.subscribe(
function (x) {
console.log('Next: Clicked!');
},
function (err) {
console.log('Error: ' + err);
},
function () {
console.log('Completed');
});
on.emit(input, 'click');
// => Next: Clicked!
});
Using in Node.js with using an EventEmitter
.
var EventEmitter = require('events').EventEmitter,
Rx = require('rx');
var e = new EventEmitter();
// Wrap EventEmitter
var source = Rx.Observable.fromEventPattern(
function add (h) {
e.addListener('data', h);
},
function remove (h) {
e.removeListener('data', h);
},
function (foo, bar) {
return foo + ',' + bar;
}
);
var subscription = source.subscribe(
function (result) {
console.log('Next: %s', result);
},
function (err) {
console.log('Error: ' + err);
},
function () {
console.log('Completed');
});
e.emit('data', 'foo', 'bar');
// => Next: foo,bar
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: