ncase.me-trust/js/lib/minpubsub.src.js
2017-06-20 07:10:41 -04:00

95 lines
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2.9 KiB
JavaScript

/*!
* MinPubSub
* Copyright(c) 2011 Daniel Lamb <daniellmb.com>
* MIT Licensed
*/
(function (context) {
var MinPubSub = {};
// the topic/subscription hash
var cache = context.c_ || {}; //check for 'c_' cache for unit testing
MinPubSub.publish = function ( /* String */ topic, /* Array? */ args) {
// summary:
// Publish some data on a named topic.
// topic: String
// The channel to publish on
// args: Array?
// The data to publish. Each array item is converted into an ordered
// arguments on the subscribed functions.
//
// example:
// Publish stuff on '/some/topic'. Anything subscribed will be called
// with a function signature like: function(a,b,c){ ... }
//
// publish('/some/topic', ['a','b','c']);
var subs = cache[topic],
len = subs ? subs.length : 0;
//can change loop or reverse array if the order matters
while (len--) {
subs[len].apply(context, args || []);
}
};
MinPubSub.subscribe = function ( /* String */ topic, /* Function */ callback) {
// summary:
// Register a callback on a named topic.
// topic: String
// The channel to subscribe to
// callback: Function
// The handler event. Anytime something is publish'ed on a
// subscribed channel, the callback will be called with the
// published array as ordered arguments.
//
// returns: Array
// A handle which can be used to unsubscribe this particular subscription.
//
// example:
// subscribe('/some/topic', function(a, b, c){ /* handle data */ });
if (!cache[topic]) {
cache[topic] = [];
}
cache[topic].push(callback);
return [topic, callback]; // Array
};
MinPubSub.unsubscribe = function ( /* Array */ handle, /* Function? */ callback) {
// summary:
// Disconnect a subscribed function for a topic.
// handle: Array
// The return value from a subscribe call.
// example:
// var handle = subscribe('/some/topic', function(){});
// unsubscribe(handle);
var subs = cache[callback ? handle : handle[0]],
callback = callback || handle[1],
len = subs ? subs.length : 0;
while (len--) {
if (subs[len] === callback) {
subs.splice(len, 1);
}
}
};
// UMD definition to allow for CommonJS, AMD and legacy window
if (typeof module === 'object' && module.exports) {
// CommonJS, just export
module.exports = exports = MinPubSub;
} else if (typeof define === 'function' && define.amd) {
// AMD support
define(function () {
return MinPubSub;
});
} else if (typeof context === 'object') {
// If no AMD and we are in the browser, attach to window
context.publish = MinPubSub.publish;
context.subscribe = MinPubSub.subscribe;
context.unsubscribe = MinPubSub.unsubscribe;
}
})(this.window);