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Ionic 2: Set interval

I am trying to set spacing in a .ts file, but I don't understand how to use a function in the same file in an interval.

Explain:

My spacing setting:

this.task = setInterval(function () {
            this.refreshData();
        }, 300);

And my function in the same ts file:

refreshData() : void{
        console.log('update...');
    }

When I start my device I have this error:

04-19 10:38:57.535 21374-21374/com.ionicframework.app722890 I/chromium: [INFO:CONSOLE(79432)] "TypeError: this.refreshData is not a function
                                                                                      at file:///android_asset/www/build/main.js:10987:18
                                                                                      at t.invokeTask (file:///android_asset/www/build/polyfills.js:3:10284)
                                                                                      at Object.onInvokeTask (file:///android_asset/www/build/main.js:39626:37)
                                                                                      at t.invokeTask (file:///android_asset/www/build/polyfills.js:3:10220)
                                                                                      at e.runTask (file:///android_asset/www/build/polyfills.js:3:7637)
                                                                                      at invoke (file:///android_asset/www/build/polyfills.js:3:11397)
                                                                                      at e.args.(anonymous function) (file:///android_asset/www/build/polyfills.js:2:30193)", source: file:///android_asset/www/build/main.js (79432)

I try this way, but I don't work:

this.task = setInterval(this.refreshData(), 300);

This is my function call only once.

Anyone have an idea?

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4 answers


use arrow function

this.task = setInterval(() => {
  this.refreshData();
}, 300);

or keep context like this

let self = this;
this.task = setInterval(function () {
  self.refreshData();
}, 300);

or using bind 



this.task = setInterval((function () {
  this.refreshData();
}).bind(this), 300);

if only one function call:

this.task = setInterval(this.refreshData.bind(this), 300);

you can read more about this from https://github.com/getify/You-Dont-Know-JS/tree/1st-ed/this%20%26%20object%20prototypes/ch1.md

+21


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You have to use setInterval () with => arrow like I mentioned below

   setInterval(() => {      
          console.log('timer');
          //you can call function here
    },5000);


100% works.

+2


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try this:

setInterval(this.refreshData, 300);
+1


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I copied the code in my application.

This worked:

this.task = setInterval( () => {
  this.refreshData();
}, 300);
+1


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