Calling class methods within jQuery function

Question

So I have some javascript class and in one method I use jQuery to bind function to click event. And within this function I need to call other methods of this class. In usual js function I did it through "this.method_name()", but here, I guess, jQuery redefines "this" pointer.

Perhaps it would help if you pasted a short code snippet. – Justin Ethier Jul 29 '10 at 16:49 — Justin Ethier, Jul 29 '10 at 16:49

score 20 · Accepted Answer · edited May 23 '17 at 12:27

20

jQuery doesn't redefine the this pointer, but that's how JavaScript functions work in general. Store a reference to the this pointer under a different name, and use that.

var self = this;
$("selector").click(function() {
    self.method_name();
});

See this answer for more approaches.

edited May 23 '17 at 12:27

Community

1
1

answered Jul 29 '10 at 16:50

Anurag

140,337
36
221
257

@Tramp - you're welcome. But note that this is still a hacky approach. Instead use `jQuery.proxy`, or even better the `bind` method that is now included in the standard. If it's not available in some browser, it's easy to define one - http://stackoverflow.com/questions/3018943/javascript-object-binding-problem-inside-of-function-prototype-definitions/3019431#3019431 – Anurag Jul 29 '10 at 17:29
Maybe this the "best approach" but I think its the most readable and less code. – John Magnolia Dec 08 '12 at 13:12

CPettit · Answer 2 · 2010-07-30T01:48:40.850

There are a few different ways to do this.

Anurag has a perfect example of one.

Two other ways are the jQuery Proxy class (Mentioned in other answers) and the 'apply' function

Now lets create an object with click events:

var MyObj = function(){

this.property1 = "StringProp";

// jQuery Proxy Function
$(".selector").click($.proxy(function(){

  //Will alert "StringProp"
  alert(this.property1);
// set the 'this' object in the function to the MyObj instance


},this));


//Apply Function
//args are optional
this.clickFunction = function(arg1){
    alert(this.property1);
};

$(".selector").click(this.clickFunction.apply(this,"this is optional"));


};

score 0 · Answer 3 · answered Dec 02 '22 at 09:45

In addition to the possibility of temporarily storing a reference to this (self = this, see Anurag's answer), since ES6 it is possible to use arrow functions for this problem. These have no "own" this. This means that the "usual" object-related this can be accessed again within an arrow function within an event handler:

$("selector").click(() => {
    this.method_name();
});

Further information: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions?retiredLocale=de#cannot_be_used_as_methods

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions?retiredLocale=de#using_call_bind_and_apply

Calling class methods within jQuery function

3 Answers3