CODEWITHSUNDEEP
javascriptclassinstancesettimeout
Spectraljump
Spectraljump

Reputation: 4617

setTimeout('classInstance.doFoo(arg)', 750); won't work

I'm trying to call an instance's method with a delay of 750ms. The problem is, it doesn't work. I've read that there's some sort of problem with setInterval and objects so probably there's one with setTimeout as well.

Say I have this:

function App()
{
      this.doFoo = function (arg)
      {
          alert("bar");
      }
}

window.app = new App();
setTimeout('app.doFoo(arg)', 750);//doesn't work
app.doFoo(arg); //works

Is there a workaround? How do I go about passing the instance and function to setTimeout?

Upvotes: 1

Views: 446

Answers (2)

Remus
Remus

Reputation: 61

i think the previous answer needs a little tweak. it is setting a global variable that you are then calling; if you really want to call an instance of your 'class' try this.

function App(message){
     this.name = 'instance';
     var self = this;
     var x = setTimeout(function(){self.doFoo(message, x);}, 750);
}
App.prototype.name = 'proto';

//creating the function on the prototype is more efficient since it is only created once.  if you do 'this.doFoo = function(){}' it's created for every instance of the function taking more memory.

App.prototype.doFoo = function(arg, timer){
 clearTimeout(timer);
 alert(this.name +' ' + arg)
}

var x = new App("hello world");
//should output ("instance hello world");

Upvotes: 2

Darin Dimitrov
Darin Dimitrov

Reputation: 1038730

Try like this:

function App()
{
    this.doFoo = function (arg) {
        alert(arg);
    }
}

window.app = new App();
window.setTimeout(function() {
    window.app.doFoo('arg');
}, 750);

Upvotes: 2

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