javascript - Setting correct this-value in requestAnimationFrame -


i have app-object constructer looks this:

var app = function(loadedsettings) {      return {         init: function() {                       this.loop();         },          loop: function() {             this.update();             window.requestanimationframe(this.loop);         },          update: function() {             //loop through settings , call update on every object.         },          settings: [              //array of settings objects, update methods.          ]     }; }

then when do:

var theapp = app(settings); theapp.init();

i get:

uncaught typeerror: object [object global] has no method 'update'

because when requestanimationframe called, this-value inside loop function set window.

does know how call requestanimatinframe 'theapp' object set this-value?

you can create bound function (with fixed this), , pass requestanimationframe:

var app = function(loadedsettings) {      return {         init: function() {                       this.loop();         },          loop: function() {             this.update();             window.requestanimationframe(this.loop.bind(this));         },          update: function() {             //loop through settings , call update on every object.         },          settings: [              //array of settings objects, update methods.          ]     }; }

i think browser supports requestanimationframe support function.prototype.bind, in case come across 1 doesn't, there polyfills available.


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