pubsubstar

Short and simple pup sub module

Features

• wildcards event string specs
• async subscribers (see publish comment)

Syopsis

• subscribe(topic, subscriber)
  • Listen for message in sent to topic; upon receipt execute subscriber with message
• unsubscribe(topics, subscriber)
  • Stop listening for messages sent to topics bound to subscriber; or
  • Stop listening for messages sent to topics bound to any subscriber (!subscriber)
  • Stop listening for messages sent to all topics bound to any subscribers (topic === '*' && !subscriber)
• publish(topics, message)
  • Send message to topics

topics parameter

May be:

• A string
  • Affects matching subscription, if any.
• A string containing * as wildcard(s)
  • Affects all matching subscriptions (subscribed topic strings).
  • Thus '*' matches all topics, 'A*y' matches topics Any and Aunty, etc.
  • To match actual occurances of * in topic string, escape with \*.
    • Don't forget to escape the backslash in JavaScript string literals!
    • Thus 'abc\\*xyz' matches topic string abc*xyz only.
• A RegExp
  • Affects all matching subscriptions.
  • Surround with ^ and $ to match to whole topic strings.

Examples

var pubsubstar = require('pubsubstar');
pubsubstar.subscribe('test', function(arg) { console.log('test(' + arg + ')'); return 7; });
var results = pubsubstar.publish('test', 3); // logs: "test(3)"
console.log(results) // logs: "[7]"

Mix in to your own objects:

var myObject = {...};
Object.assign(myObject, require('pubsubstar'));
myObject.subscribe(...);
myObject.publish(...);

var MyClass = function() {}
Object.assign(MyClass.prototype, require('pubsubstar'));
var myInstance = new MyClass();
myInstance.subscribe(...);
myInstance.publish(...);

Arbitrary context:

var api = {...};
pubsubstar.subscribe.call(api, ...);
pubsubstar.publish.call(api, ...);