initial commit

libjs/utils/subscribable.js

@@ -0,0 +1,94 @@
+"use strict";
+
+var Class = require("./class");
+
+var Subscribable = Class.inherit({
+    "className": "Subscribable",
+    "constructor": function() {
+        Class.fn.constructor.call(this);
+
+        this._events = Object.create(null);
+    },
+    "destructor": function() {
+        this.off();
+        Class.fn.destructor.call(this);
+    },
+
+    "on": function(name, handler, context) {
+        var handlers = this._events[name];
+
+        if (typeof name !== "string") {
+            throw new Error("Name of event is mandatory");
+        }
+
+        if (!(handler instanceof Function)) {
+            throw new Error("Handler of event is mandatory");
+        }
+
+        if (!handlers) {
+            handlers = [];
+            this._events[name] = handlers;
+        }
+
+        handlers.push({
+            handler: handler,
+            context: context || this,
+            once: false
+        });
+    },
+    "one": function(name) {
+        Subscribable.fn.on.apply(this, arguments);
+        this._events[name][this._events[name].length - 1].once = true;
+    },
+    "off": function(name, handler, context) {
+
+        if (typeof name === "string") {
+            if (this._events[name]) {
+                if (handler instanceof Function) {
+                    var handlers = this._events[name];
+                    for (var i = handlers.length - 1; i >= 0 ; --i) {
+                        if (handlers[i].handler === handler) {
+                            if (context) {
+                                if (handlers[i].context === context) {
+                                    handlers.splice(i, 1);
+                                }
+                            } else {
+                                handlers.splice(i, 1);
+                            }
+                        }
+                    }
+                } else {
+                    delete this._events[name];
+                }
+            }
+        } else {
+            this._events = Object.create(null);
+        }
+    },
+    "trigger": function() {
+        var args = [].slice.call(arguments);
+        if (args.length === 0) {
+            throw new Error("Name of event is mandatory");
+        }
+        var answer = false;
+        var name = args.shift();
+        var handlers = this._events[name];
+        if (handlers) {
+            for (var i = 0; i < handlers.length; ++i) {
+                var handle = handlers[i];
+                answer = handle.handler.apply(handle.context, args);
+                if (handle.once) {
+                    handlers.splice(i, 1);
+                    --i;
+                }
+
+                if (answer === false) {
+                    return false;
+                }
+            }
+        }
+        return answer;
+    }
+});
+
+module.exports = Subscribable;