RxJS

01_observable_creation.js

var source = Rx.Observable.create(function (observer) {
    setTimeout(() => observer.onNext(42), 0);
    setTimeout(() => {
      observer.onNext(7);
      observer.onNext(11);
      observer.onCompleted();
    }, 500);

    // Note that this is optional, you do not have to return this if you require no cleanup
    return Rx.Disposable.create(() => console.log('disposed'));
});

var subscription = source
  .filter(x => x > 10)
  .map(x => x * x)
  .subscribe(
    x => {
      console.log('Next: ', x);
      if (x > 1000) {
        subscription.dispose();
      }
    },
    err => console.error('Error: ', err),
    () => console.log('Completed')
  );

setTimeout(() => subscription.dispose(), 200);

02_sync-rx-eventemitter.js

// http://jsbin.com/viwizisejo/1/edit?html,js,console

var hasOwnProp = {}.hasOwnProperty;

function createName (name) {
    return '$' + name;
}

function Emitter() {
    this.subjects = {};
}

Emitter.prototype.emit = function (name, data) {
    var fnName = createName(name);
    this.subjects[fnName] || (this.subjects[fnName] = new Rx.Subject());
    this.subjects[fnName].onNext(data);
};

Emitter.prototype.on = function (name) {
    var fnName = createName(name);
    this.subjects[fnName] || (this.subjects[fnName] = new Rx.Subject());
    return this.subjects[fnName];
};

Emitter.prototype.dispose = function () {
    var subjects = this.subjects;
    for (var prop in subjects) {
        if (hasOwnProp.call(subjects, prop)) {
            subjects[prop].dispose();
        }
    }

    this.subjects = {};
};

var emitter = new Emitter();
emitter.on('foo')
.filter(function(x) { return x >= 42 })
.forEach(function(a) {
  console.log('Filtered: ', a);
});

var subscription = emitter.on('foo')
.forEach(function(a) {
  console.log('Unfiltered: ', a);
});

emitter.emit('foo', 3)
emitter.emit('foo', 42)
subscription.dispose();
emitter.emit('foo', 43)
emitter.emit('foo', 41)
console.log('bar');