Calling setInterval within an object, overrides "this"

Asked Feb 08 '18 at 20:14

Active Feb 08 '18 at 20:14

Viewed 26 times

I'm writing a code to perform a "watch" on some resource in an api : Considering my code :

function myObj(){
   this.endpoint  = "/example"; // my endpoint
   this.interval = 500; // my watch interval
}

myObj.prototype.watch = function(){
   console.log(this.endpoint); // returns "/example"
   this.intervalId = setInterval(this.refresh, this.interval);
}

myObj.prototype.destroy= function(){
   clearInterval(this.intervalId);
}

myObj.prototype.refresh = function(){

   console.log(this.endpoint) // -> undefined ??? 

}

asked Feb 08 '18 at 20:14

M. Gara

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4

You lose scope of `this` inside the interval, `bind()` it – Sterling Archer Feb 08 '18 at 20:15
3

`setInterval(this.refresh.bind(this), this.interval)` – dfsq Feb 08 '18 at 20:17
Its a duplicate of this https://stackoverflow.com/questions/7890685/referencing-this-inside-setinterval-settimeout-within-object-prototype-methods @Patrick Evans – M. Gara Feb 08 '18 at 20:23
1

start constructor function name with a capital letter (it has nothing to do with your problem but this is a convention) – Engineer Passion Feb 08 '18 at 20:25
sure @EngineerPassion Thanks – M. Gara Feb 08 '18 at 20:26
1

It's either one, you are trying to use a class method as a callback, and losing execution context. The one I linked is more informative. – Patrick Evans Feb 08 '18 at 20:26

Calling setInterval within an object, overrides "this"

0 Answers0