phosphor-signaling

phosphor-signaling

A module for type-safe inter-object communication.

API Docs

Package Install

Prerequisites

• node

npm install --save phosphor-signaling

Source Build

Prerequisites

• git
• node

git clone https://github.com/phosphorjs/phosphor-signaling.git
cd phosphor-signaling
npm install

Rebuild

npm run clean
npm run build

Run Tests

Follow the source build instructions first.

npm test

Build Docs

Follow the source build instructions first.

npm run docs

Navigate to docs/index.html.

Supported Runtimes

The runtime versions which are currently known to work are listed below. Earlier versions may also work, but come with no guarantees.

• Node 0.12.7+
• IE 11+
• Firefox 32+
• Chrome 38+

Usage Examples

Note: Except where explicitly noted in the examples, this module is fully compatible with Node/Babel/ES6/ES5. Simply omit the type declarations when using a language other than TypeScript.

Start by defining the model object and its signals:

// Omit the `ISignal` import on Node/Babel/ES6/ES5
import { ISignal, defineSignal } from 'phosphor-signaling';


class Model {

  // See below for Node/Babel/ES6/ES5 equivalent
  @defineSignal
  itemAdded: ISignal<{ index: number, item: string }>;

  constructor(name) {
    this._name = name;
  }

  get name(): string {
    return this._name;
  }

  get items(): string[] {
    return this._items.slice();
  }

  addItem(item: string): void {
    var i = this._items.length;
    this._items.push(item);
    this.itemAdded.emit({ index: i, item: item });
  }

  private _name: string;
  private _items: string[] = [];
}

// Node/Babel/ES6/ES5 `@defineSignal` decorator alternative
defineSignal(Model.prototype, 'itemAdded');

Next, define the handler(s) which will consume the signals:

If the same handler is connected to multiple signals, it may want to get a reference to the object emitting the signal which caused it to be invoked. This can be done with the emitter() function.

import { emitter } from 'phosphor-signaling';


function logger(args: { index: number, item: name }): void {
  var model = <Model>emitter();
  console.log(model.name, args.index, args.name);
}


class ItemCounter {

  constructor(model: Model, item: string) {
    this._model = model;
    this._item = item;
    model.itemAdded.connect(this._onItemAdded, this);
  }

  dispose(): void {
    this._model.itemAdded.disconnect(this._onItemAdded, this);
    this._model = null;
  }

  get count(): number {
    return this._count;
  }

  private _onItemAdded(args: { index: number, item: name }): void {
    if (args.item === this._item) this._count++;
  }

  private _model: Model;
  private _name: string;
  private _count = 0;
}

Next, connect the handlers to the signals:

var m1 = new Model('foo');
var m2 = new Model('bar');
var m3 = new Model('baz');

var c1 = new ItemCounter(m1, 'quail');
var c2 = new ItemCounter(m1, 'robbin');
var c3 = new ItemCounter(m1, 'chicken');

m1.itemAdded.connect(logger);
m2.itemAdded.connect(logger);
m3.itemAdded.connect(logger);

Make some changes to the models:

m1.addItem('turkey');
m1.addItem('fowl');
m1.addItem('quail');

m2.addItem('buzzard');

m3.addItem('hen');

Disconnect the logger from all models in a single-shot:

import { disconnectReceiver } from 'phosphor-signaling';

disconnectReceiver(logger);

Disconnect a particular model from all handlers in a single-shot:

import { disconnectEmitter } from 'phosphor-signaling';

disconnectEmitter(m1);