watcher

A small (~400 bytes gzipped) Pub/Sub plugin for implementing broadcasters in jQuery

Usage

import 'watcher-min.js'

// subscribe to (watch) an event
var sub1 = $.watcher('subscribe', '/myEvents/event1', function(results) {
    console.log('Event received', result);
});

// publish an event
$.watcher('publish', '/myEvents/event1', {myParam : 'Param Value'});

// unsubscribe to an event
$.watcher('unsubscribe', '/myEvents/event1', sub1);

// remove all subscribers from an event
$.watcher('unsubscribeAll', '/myEvents/event1');

// get all subscribers to an event
var myWatchers = $.watcher('getWatchers', '/myEvents/event1');

API

The watcher plugin runs as a singleton so every call (listed below) gets wrapped into the $.watcher() method.

The signature for every call is as follows: $.watcher(action, event, handler/data);

Parameters

• action String : Type of action to execute on the $.watcher plugin
• event String : Type (name) of event
• handler Function : (Subscribe Only) Function to call or execute when the event being watched is published
• data Object : (Publish Only) A collection of key/value pairs to be passed along to any subscribers of the event

getWatchers

Get a reference to all subscribers of a specific event.

Parameters

• event String : Type (name) of event to watch

Returns

• watchers Array : An array of references to subscribers to the specified event

publish

Broadcast an event to all subscribers

Parameters

• event String : Type of event to unregister handler from, or "*"
• data Object : A collection of key/value pairs to be passed along to any subscribers of the event

subscribe

Listens for an event to be broadcast and executes a handler (callback) method Will also receive a results object allowing for additional parameters to be passed from the broadcaster

Parameters

• event String : Type (name) of event to watch
• handler Function : Function to call or execute when the event being watched is published

unsubscribe

Removes a specific watcher from an event subscription This is good practice to do when the subscription is no longer needed to mark for garbage cleanup

Parameters

• event String : Type (name) of event to unsunscribe from
• reference [Any] : A variable reference to whatever was used when setting up the watcher initially

unsubscribeAll

Removes all watchers from an event subscription This is good practice to do when the event is no longer needed to mark all watchers for garbage cleanup

Parameters

• event String : Type (name) of event to remove subscribers from