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.

• Justin Ethier: Perhaps it would help if you pasted a short code snippet.

Answer 1

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.

• Anurag: @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 - stackoverflow.com/questions/3018943/…
• John Magnolia: Maybe this the "best approach" but I think its the most readable and less code.

Answer 2

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"));
};

Answer 3

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