Single-file JavaScript module: Attaches pub/sub behavior to the given object or constructor

pubsub-v1.0.0.js

/* Attaches pub/sub behavior to the given object. Returns a function that
   attaches pub/sub behavior, including an *eventListeners* property, to the
   given object or prototype function. Usage is simple; assume TestObj is a
   constructor:

    > pubsub(TestObj);
    > var to = new TestObj();
    > to.subscribe('trigger', function(eventObj) {
        console.log(this);
        console.log(eventObj);
      });
    > to.publish('trigger', {
        timestamp: (new Date()).toUTCString()
      });

   You can also directly attach to any object. Tags are case-insensitive:

    > let o = {"one": 1, "two": 2};
    > pubsub(o);
    > o.subscribe("STUFF_HAPPENS", console.log);
    > o.publish("stuff_happens", { "context": this });
*/

if (typeof (define) != "function") { var define = require("sfjm").define.bind(exports); var window = {}; }
define(function (require, module, exports) {
    function pubsub(obj) {
        var tgt = obj;
        if (obj.prototype) {
            tgt = obj.prototype;
        }
        tgt.publish = publish.bind(tgt);
        tgt.subscribe = subscribe.bind(tgt);
        tgt.eventListeners = {};
    }

    function publish(eventTag, eventObj) {
        if (typeof (eventObj) == 'undefined') { eventObj = {}; }
        if (Object.keys(this.eventListeners).indexOf(eventTag) < 0) {
            this.eventListeners[eventTag] = [];
        }
        this.eventListeners[eventTag].forEach(function (listener) {
            listener.call(this, eventObj);
        }, this);
    }

    function subscribe(eventTag, listener) {
        if (Object.keys(this.eventListeners).indexOf(eventTag) < 0) {
            this.eventListeners[eventTag] = [];
        }
        this.eventListeners[eventTag].push(listener);
    }

    return Object.assign(pubsub, {
        "__uni__": "com.github.gist.tythos.pubsub",
        "__semver__": "1.0.0",
        "__author__": "code@tythos.net",
        "__license__": "MIT" // SPDX Identifier
    });
});