Accessing a Javascript prototype function

Question

I have a prototype function such as event.

Prototype

Func("input_element_id").event("keyup",function(){
    alert("Works on keyup in an Input!");
}

Func.prototype= {
    keyup: function(func){
         //adding event listener and callback using func
    },
    event: function(e,func) {
         //what to do here to call function "keyup"
    }
};

The prototype name is in the variable e. But how can i call that function using the variable name?

I am doing this, so that passing "keyup keydown" will add keyup and keydown listeners, which is better than calling each prototype function individually.

Thanks.

lashab · Accepted Answer · 2013-07-21 16:53:47Z

2

var Func = function(element){
  this.element = element;
};

Func.prototype = {
    keyup: function(handler){
      this.element.onkeyup = handler;
    },
    event: function(e,handler){
        switch(e){
            case 'keyup':
              return this.keyup(handler);
            break;
        }
    }
}

http://jsfiddle.net/YDekw/

answered Jul 21, 2013 at 16:53

lashab

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Comments

Ry- · Accepted Answer · 2013-07-21 15:07:42Z

0

Access the receiving object with this.

this.keyup(func);

Assuming a decent browser or an ES5 shim, looks like you want to do this:

e.split(" ").forEach(function(f) {
    this[f](func);
}, this);

Note that it’s just whatever object is being used with the dot operator, though, and could be anything. For example:

var f = new Func("input_element_id");
window.event = f.event;
window.event(); // this is window

edited Jul 21, 2013 at 15:07

answered Jul 21, 2013 at 14:53

Ry-♦

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12 Comments

user2437417 Over a year ago

e is a string representing the property OP wants to access. You should be doing this[e](func)

user2437417 Over a year ago

.event("keyup",function(){ alert("Works on keyup in an Input!"); }

Ry- Over a year ago

@Harikrishnan: That won’t work space-separated at all. See update. I was debating whether to add that, but looks like I may as well.

Hari krishnan Over a year ago

@minitechi i figured how to do when coming into spaces. But dont know how to access when that is in a variable or when e is a string representing the property OP wants to access

user2437417 Over a year ago

Your answer was this.keyup(func);. You simply failed to read the question. Using this was certainly part of the issue though. Either way, your .forEach() solution is incorrect.

|

Hari krishnan · Accepted Answer · 2013-07-22 14:46:31Z

0

The best way to achieve this is by:

events: function(events,func) {
            this[events](func);
        }
    }

Thanks to CrazyTrain, As he mentioned in Comments.

answered Jul 22, 2013 at 14:46

Hari krishnan

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3 Comments

Ry- Over a year ago

So what happened to the spaces?

Hari krishnan Over a year ago

@minitech i didnt ask question with adding spaces. I just mentioned why i am doing like this.

Ry- Over a year ago

To quote your question, I am doing this, so that passing "keyup keydown" will add keyup and keydown listeners, which is better than calling each prototype function individually.. That makes sense… if you just want to add an event by name, instead of making a different function for each one, I’d use element.addEventListener(singleEventName, func);. (With appropriate IE compatibility if you’d like.) Making a different function for each one is probably going to be a bit tedious.

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