Problem with prototype property javascript

Question

I am having trouble trying to get this to run. I am trying to use the observer pattern. I wnant to be able to run a arbitry amount of functions on the select change event. I keep getting an error 'Publisher.protoype' is null or not an object. What am I doing wrong?

        function Publisher(){
            this.subscribers = [];
        }

        Publisher.protoype.deliver = function(data){
            this.subscribers.forEach(
                function(fn){
                    fn(data);
                }
            );
            return this;
        }

        Function.prototype.subscribe = function(publisher){
            var that = this;
            var AlreadyExists = publisher.subscribers.some(
                function(el){
                    if (el == that){
                        return;
                    }
                }
            );
            if(!AlreadyExists){
                publisher.subscribers.push(this);
            }
            return this;
        }

        Function.prototype.unsubscribe = function(publisher){
            var that = this;
            publisher.subscribers = publisher.subscribers.filter(
                function(el){
                    if(el != that){
                        return el;
                    }
                }
            );
            return this;
        }
        var EventPublisher = new Publisher();      
        var SelectChange = function(data){alert("hello")};
        SelectChange.subscribe(EventPublisher);
        function onSelectChange(oSelect){
            EventPublisher.deliver(oSelect);
        }

    </script>

</head>

<body>
    <form name="Tester" action="Tester" method="post" enctype="application/x-www-form-urlencoded">
        <select name="selecter" onchange="Javascript:onSelectChange(this)">
            <option name="Shane" value="Shane">
                Shane
            </option>

            <option name="Shane2" value="Shane2">
                Shane2
            </option>
        </select><input type="submit"><input type="reset">
    </form>
</body>
</html>

Dan Iveson · Accepted Answer · 2010-12-08 10:59:24Z

2

You have a typo: Publisher.protoype.deliver is missing a 't'.

answered Dec 8, 2010 at 10:59

Dan Iveson

9366 silver badges10 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Shane Over a year ago

Well tha deserves a face slap! :P Thanks for that!

Joel Etherton Over a year ago

@Shane - missing a t in that comment too. Might want to have your keyboard checked ;)

Joel Etherton · Accepted Answer · 2010-12-08 11:00:05Z

0

Publisher.protoype is definitely null or not an object. Perhaps you meant to type Publisher.prototype.

answered Dec 8, 2010 at 11:00

Joel Etherton

37.5k10 gold badges92 silver badges106 bronze badges

Collectives™ on Stack Overflow

Problem with prototype property javascript

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related