cjs-noticeboard v0.0.7

CJS-NOTICEBOARD

WHAT IS A NOTICEBOARD?

A Noticeboard is just the Pub-Sub pattern with a twist: most-recently published values are cached and accessible by future subscribers.

HOW TO USE IT

Install

	npm install cjs-noticeboard

Basic Use

Create New Noticeboard

	var Noticeboard = require('cjs-noticeboard'),
		board = new Noticeboard();

Subscribe to Notice

	
	var notice = 'new-user',
		watcher = 'greet-new-users';

	board.watch( notice, watcher, function( message ){

		console.log( "Hello " + message.notice.username + "!" );
	});

Publish to Notice Watchers

	board.notify( 'new-user', { username: 'akamaozu' });

Stop Subscribing to a Notice

	
	board.ignore( 'new-user', 'greet-new-users' )

Advanced Use

Unsubscribe Immediately After Responding to a Notice

	
	board.once( 'new-user', 'identify-first-user-only', function( message ){

		console.log( "First User: " + message.notice.username );
	});

Use Previous Notice and Subscribe to Future Notices

	
	board.watch( 'window-size', 'log-window-size', function( message ){

		console.log( "w: " + message.notice.width  " | h: " + message.notice.height );

	}, { useCache: true });

Enable Noticeboard Log Feature

	var Noticeboard = require('cjs-noticeboard'),
		board = new Noticeboard({ logging: true });

	// or

	board.settings.logging = true;

Enable Noticeboard Internal Operation Logging

Note: Noticeboard must have settings logging set to true

	var Noticeboard = require('cjs-noticeboard'),
		board = new Noticeboard({ logOps: true });

	// or

	board.settings.logOps = true;

Handle Noticeboard Logs

	
	board.watch( 'log-entry', 'process-board-logs', function( message ){

		var entry = message.notice;

		console.log.apply( console, entry );
	});

API

===

new Noticeboard(settings)

Create a new Noticeboard Instance. Behavior can be configured with settings.

• Is a Function
• Arguments settings type: Object {} required: false props: logging type: Boolean (true or false) required: false desc: Determines if the Noticeboard will notify subscribers of log-entry. logOps type: Boolean (true or false) required: false desc: Determines if the Noticeboard will publish notices about its internal operations to log-entry watchers.

Noticeboard.notify(notice, message, source)

Triggers the callback in every watcher of the specified notice. If there is a non-null message, the notification will be cached. The source is for attribution / debugging purposes.

• Is a Function
• Arguments notice type: String required: true message type: Any required: false gotchas: 1. notifications with a message will automatically be cached. 2. notifications without a message will not be cached. 3. notifications with the message object null will not be cached. source type: String required: false

Noticeboard.watch(notice, watcher, callback, options)

Adds a watcher to the list of callbacks to execute when a notice is sent out. The execution context and parameters of the callback can be modified via options.

• Is a Function

• Arguments notice type: String required: true watcher type: String required: true callback type: Function required: true arguments passed: Object {} arguments props: notice description: message passed from Noticeboard.notify watcher description: message passed from Noticeboard.watch options type: Object {} required: false props: message type: Any required: false * description: Passed to callback on execution. accessible inside callback as arguments0.watcher

  		* **useCache**
  			* type: Boolean (`true` or `false`)
  			* required: false
  			* description: Set to true if its okay to autofire the callback if the notification has been previously cached
  
  		* **once**
  			* type: Boolean (`true` or `false`)
  			* required: false
  			* description: Set to true if you want this watcher to autoignore the notice immediately after its callback. 

Noticeboard.ignore(notice, watcher)

Remove a watcher from the list of callbacks to execute when this notice is sent out.

• Is a Function
• Arguments notice type: String required: true watcher type: String required: true

Noticeboard.once(notice, watcher, callback, options)

A simple wrapper around Noticeboard.watch that calls Noticeboard.ignore as soon as its callback is executed. See Noticeboard.watch for details this function's parameters.

Noticeboard.log()

Designed to simulate the browser's console.log, this function will notify all watchers of log-entry and pass its arguments object as the message.

For instance, this is equivalent to calling console.log, with the added benefit of not crashing if the browser doesn't have console. That and your log can be piped to other parts of your app.

Noticeboard.watch('log-entry', 'browser-console', function(msg){
	if(!console || typeof console.log !== "function"){ return; }

	console.log.apply(console, msg.notice);
}

With the above watcher, the snippet below is now a superior version of console.log.

Noticeboard.log("testing", {isTest: true}, [1,2,3], function(){})

CONTACT ME

• Pull Requests
• Email: uzo@designbymobius.ca
• Twitter: @akamaozu
• Carrier Pigeons

Hop on the Noticeboard Train!

You're waiting for a train
A train that will take you far away
You know where you hope this train will take you
But you don't know for sure
Yet it doesn't matter
Because we'll be together

-- Mal (Inception, 2010)