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');

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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

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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

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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

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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

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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

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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