CODEWITHSUNDEEP
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Tancrede Chazallet
Tancrede Chazallet

Reputation: 7255

Get "this" within the parent class

My problem is I can't access the proper this object in my parent class.

Parent class :

ViewController.prototype.display = function() {
    console.log(this); // Log a Window object
};

Child class :

ParentMissionsViewController.prototype = Object.create(ViewController.prototype);
ParentMissionsViewController.prototype.constructor = ParentMissionsViewController;
ParentMissionsViewController.prototype.parent = ViewController.prototype;

ParentMissionsViewController.prototype.display = function() {
    // Other stuff here
    this.parent.display.call();
};

I don't get why this isn't my current object, if someone can explain me ?

Upvotes: 0

Views: 78

Answers (2)

Kos
Kos

Reputation: 72329

If you call

this.parent.display();

then it looks like:

var that = this.parent;
that.display();

which you, as I suppose, wanted to avert. Using call is the good way, but you need to provide the value for this:

this.parent.display.call(this /* , arg, arg... */);

See the signature of call at MDN.

Upvotes: 3

Ashutosh Upadhyay
Ashutosh Upadhyay

Reputation: 481

Try 

this.parent.display();

When you use call to invoke a method, you need to specify custom this value as first argument. What this value are you getting in current code? I am guessing undefined?

Upvotes: 0

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