https://github.com/brynbellomy/switchboard.js

Multi-events for the browser and node.js (i.e., handlers won't trigger until several specified events occur).
https://github.com/brynbellomy/switchboard.js

Last synced: about 1 month ago
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Multi-events for the browser and node.js (i.e., handlers won't trigger until several specified events occur).

• Host: GitHub
• URL: https://github.com/brynbellomy/switchboard.js
• Owner: brynbellomy
• Created: 2011-06-30T09:35:29.000Z (over 13 years ago)
• Default Branch: master
• Last Pushed: 2012-12-01T01:05:33.000Z (almost 12 years ago)
• Last Synced: 2024-09-11T23:26:46.829Z (2 months ago)
• Language: JavaScript
• Homepage: http://brynbellomy.github.com/switchboard.js
• Size: 185 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# // switchboard.js

A composite event listener.  Waits for several events to occur before firing the handler.

Switchboard returns the arguments of each respective `emit` to the specified handler.  These arguments can be named if desired.

## Installing

node.js:

```sh

npm install switchboard

```

bower:

```sh

bower install switchboardjs

```

```html

```

## Why do I need this?

Sometimes you have to wait for 2 or more things to happen before a certain part

of your program can move forward.  Let's say you're rendering a bunch of

templates, for example.  You want to do it asynchronously, but it's kind of a

pain to figure out when everything's done without something kludgey (like a

static counter or a jungle of if statements).  **switchboard.js** can hide the

kludge for you.

Familiar syntax, too.  Just uses the classic EventEmitter 'on/once' pattern.

Except instead of a single event name, you specify an array.

## How to use

You've got two choices, cowboy.

### 1. Extremely simple way

```javascript

var Switchboard = require('switchboard').Switchboard,

    myEmitter   = new Switchboard();

var events = ['firstEvent', 'secondEvent', 'thirdEvent'];

myEmitter.on(events, function(args) {

  // after calling `myEmitter.emit(e)` for all three events, args is something like:

  // { 'firstEvent':  [ ... the args ... ],

  //   'secondEvent': [ ... the args ... ],

  //   ...

  // }

  // etc.

});

```

### 2. With a little bit more code, you get your results returned in a dictionary!

```javascript

var Switchboard = require('switchboard').Switchboard,

    myEmitter   = new Switchboard();

var events = ['firstEvent', 'secondEvent', 'thirdEvent'];

myEmitter.registerEventArguments({

  firstEvent: ['err', 'resultA', 'resultB']

});

// multiple calls to registerEventArguments are a-okay

// (hint: good for loops or for registering callbacks from

// within other callbacks)

myEmitter.registerEventArguments({

  secondEvent: ['resultC', 'resultD', 'resultE'],

  thirdEvent:  ['err', 'myVar', 'someJunk']

});

myEmitter.once(events, function(args) {

  console.log(args)

});

```

Now that you've defined your events, you can go ahead and emit things...

```javascript

myEmitter.emit('firstEvent', null, 'aaaa', 'bbbbb')

myEmitter.emit('thirdEvent', {err: 'someErr'}, 'mvvvarrr', 'junk~!')

myEmitter.emit('secondEvent', 'CCCC', 222222, 'EEEE')

```

Which will produce the following output:

```javascript

{ firstEvent: 

  { '0': null,

    '1': 'aaaa',

    '2': 'bbbbb',

    err: null,

    resultA: 'aaaa',

    resultB: 'bbbbb' },

secondEvent: 

  { '0': 'CCCC',

    '1': 222222,

    '2': 'EEEE',

    resultC: 'CCCC',

    resultD: 222222,

    resultE: 'EEEE' },

thirdEvent: 

  { '0': { err: 'someErr' },

    '1': 'mvvvarrr',

    '2': 'junk~!',

    err: { err: 'someErr' },

    myVar: 'mvvvarrr',

    someJunk: 'junk~!' } }

```

As you can see, each event's arguments are enumerated as well as being named.  The point: you can skip the call to `registerEventArguments()` if you want.