extending an object with new functions in Javascript

Question

Basically Dub and Dub.socialize objects already exist as an included library. I'm trying to extend the library with some additional custom functions that I created.

I attempted the following concept below:

Dub.socialize = {
    setUID : function(preUID, postUID)
    {
        // .. function code here
    }
}

However, I receive the following error "Uncaught TypeError: Cannot set property 'setUID' of undefined" from my console.

Obviously my knowledge of objects is a bit misled. What would be the proper method of extending this function into the already existing object library?

That error doesn't really seem to fit with an object literal like you have in the snippet. Are you attempting to reassign setUID? Dub.socialize.setUID = ...;? — Jonathan Lonowski
– Jonathan Lonowski, Commented Mar 5, 2014 at 16:38
If Dub.socialize already exists, you can do Dub.socialize.setUID = function ()... — Nikola Dimitroff
– Nikola Dimitroff, Commented Mar 5, 2014 at 16:43
@NikolaDimitroff - if Dub.socialize already exists, he must do it the way you showed, with his code he loses the existing object with all its existing methods/properties. — Igor
– Igor, Commented Mar 5, 2014 at 17:04

Rajesh Dhiman · Accepted Answer · 2014-03-05 16:45:39Z

1

A simple solution could be

Dub.socialize.setUID =  function(preUID, postUID) {};

answered Mar 5, 2014 at 16:45

Rajesh Dhiman

1,8961 gold badge18 silver badges30 bronze badges

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

Comments

Dissident Rage · Accepted Answer · 2014-03-27 14:27:43Z

1

Try this:

Dub.socialize.prototype.setUID = function(preUID, postUID) {
    ...
};

Object Constructor and prototyping

Edit: Realized you're working with a "static" object. This only works for something that is instantiated, and since you're not making new instances, this doesn't apply.

edited Mar 27, 2014 at 14:27

answered Mar 5, 2014 at 16:43

Dissident Rage

2,7361 gold badge29 silver badges33 bronze badges

2 Comments

tfont Over a year ago

Dissdent, I figured it was indeed in relation to "prototyping", however it doesn't seem to fit properly. One should still receive the error "Uncaught TypeError: Cannot set property 'setUID' of undefined".

Dissident Rage Over a year ago

Yeah, I realized that the reason this didn't work is because prototyping is for creating instance objects (e.g. new Dub.socialize()) rather than attaching to a "static" object.

kirubakar · Accepted Answer · 2014-03-05 20:36:20Z

0

If you are going to create the function for declared object means then you have to use "prototype" keyword for example.

`var Dub = { socialize: new Object() };

Dub.socialize.prototype.setUID = function(preUID, postUID) { // Function Body };`

http://www.javascriptkit.com/javatutors/proto3.shtml

answered Mar 5, 2014 at 20:36

kirubakar

1992 silver badges6 bronze badges

Collectives™ on Stack Overflow

extending an object with new functions in Javascript

3 Answers 3

Comments

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related