How to call a function that is inside another function javascript

Question

I have two files as below:

trycapture.js (which has) trycapture() (which has) drawaggregate() definition
main.js from which I want to call drawaggregate();

trycapture.js

trycapture(){
... some code
function drawaggregate(){
... definition
   }
}

main.js

.. some variables
var try_obj = new trycapture();
try_obj.drawAggregate(emit_x1,emit_y1,emit_x2,emit_y2);

HTML

<head>
<script src="trycapture.js"></script>
<script src="js/main.js"></script>
</head>

How can I call that function. I tried creating an object right before calling drawaggregation() such as above:

I still get the error:

TypeError:try_obj.drawaggregate is not a function

Also, in index.html I made sure that I include trycapture.js before main.js How can I call that function?

Can you include some actual code for how your functions are set up? — ssube, Jun 10 '16 at 19:26
without seeing your source code there's no way to help solve your problem. Please review [ask], and include a [mcve]. Otherwise, this question is [off-topic (#1)](/help/on-topic) and should be closed as such. — zzzzBov, Jun 10 '16 at 19:26
`console.log(try_obj)` first to see what's actually in `try_obj`. Is it creating the object you expect? Is your call to `drawaggregate` using the correct capitalization, spelling, etc? Some more code would probably be useful here :) — Sander Moolin, Jun 10 '16 at 19:26
Are you including both files in your HTML page? Is trycapture.js included before main.js? — Spivonious, Jun 10 '16 at 19:28
There's a lot of things being thrown at you in these comments, but basically we just need to know how you're loading your JavaScript files. HTML source would help. — gcampbell, Jun 10 '16 at 19:31

FactoryAidan · Accepted Answer · 2016-06-10T22:02:52.110

1

Add

this.drawaggregate = drawaggregate;

after your function definition to make it a public method of the trycapture object.

Overall, you will change your trycapture.js to the following:

function trycapture(){
    ... some code

    // Locally accessible only
    function drawaggregate(){
        ... definition
    }
    this.drawaggregate = drawaggregate; // Makes it publicly accessible also
}

the drawaggregate() method can then be called like so:

var try_obj = new trycapture();
try_obj.drawaggregate();

edited Jun 10 '16 at 22:02

answered Jun 10 '16 at 19:44

FactoryAidan

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I am able to call the function even without the object now. Is that normal? – Arihant Jun 10 '16 at 19:57
Yes, it's normal. It depends on many things and more than can fit in this comment box. So explaining here could be incomplete and confusing. EXAMPLE1: If you happen to call your `new trycapture()` from inside an anonymous function such as an `onload` event listener, then `this` inside of `trycapture` would refer to the `window` object instead. Thus, `drawaggregate` would become a global window function callable from anywhere. EXAMPLE2: If you are inside the `trycapture` function namespace, you are allowed to(and should) call `drawaggregate` as a local function instead of a method of an object. – FactoryAidan Jun 10 '16 at 21:57

How to call a function that is inside another function javascript

1 Answers1