I'm creating a d.ts file for webgl-utils.js from google

I have a problem with one of the last lines where a method in a global object is 'monkey patched' (I think this is the right terminology)

The problem line reads:

 /**
  * Provides requestAnimationFrame in a cross browser way.
  */
 window.requestAnimFrame = (function() {
   return window.requestAnimationFrame ||
          window.webkitRequestAnimationFrame ||
          window.mozRequestAnimationFrame ||
          window.oRequestAnimationFrame ||
          window.msRequestAnimationFrame ||
          function(/* function FrameRequestCallback */ callback, /* DOMElement Element */ element) {
            window.setTimeout(callback, 1000/60);
          };
 })();

How would I declare this in my typescript file so I won't get pile errors when I use the function:

 function tick()
 {
      requestAnimFrame(tick);
      drawScene();
 }

I now have tried:

 interface window
 {
      requestAnimFrame(): any;
 }

But this doesn't remove the error:

 The name 'requestAnimFrame' does not exist in the current scope

I'm creating a d.ts file for webgl-utils.js from google

I have a problem with one of the last lines where a method in a global object is 'monkey patched' (I think this is the right terminology)

The problem line reads:

 /**
  * Provides requestAnimationFrame in a cross browser way.
  */
 window.requestAnimFrame = (function() {
   return window.requestAnimationFrame ||
          window.webkitRequestAnimationFrame ||
          window.mozRequestAnimationFrame ||
          window.oRequestAnimationFrame ||
          window.msRequestAnimationFrame ||
          function(/* function FrameRequestCallback */ callback, /* DOMElement Element */ element) {
            window.setTimeout(callback, 1000/60);
          };
 })();

How would I declare this in my typescript file so I won't get pile errors when I use the function:

 function tick()
 {
      requestAnimFrame(tick);
      drawScene();
 }

I now have tried:

 interface window
 {
      requestAnimFrame(): any;
 }

But this doesn't remove the error:

 The name 'requestAnimFrame' does not exist in the current scope

• javascript
• declaration
• typescript

• Have you tried explicitly prefixing it with window.? – Bergi Commented Feb 5, 2013 at 20:45
• Yes, that gives the identical error – Toad Commented Feb 5, 2013 at 21:15
• also, the intellisense in VisStudio doesn't show the method. It does show the normal: requestAnimationFrame() but not the new one – Toad Commented Feb 5, 2013 at 21:16

4 Answers 4

You were heading in the right direction, but you need to define all of the variations you have:

 interface Window {
     requestAnimFrame(callback: any, element?: any): void;
     webkitRequestAnimationFrame(callback: any, element?: any): void;
     mozRequestAnimationFrame(callback: any, element?: any): void;
     oRequestAnimationFrame(callback: any, element?: any): void;
 }

 window.requestAnimFrame = (function() {
    return window.requestAnimationFrame ||
        window.webkitRequestAnimationFrame ||
        window.mozRequestAnimationFrame ||
        window.oRequestAnimationFrame ||
        window.msRequestAnimationFrame ||
        function(callback, element?) {
            window.setTimeout(callback, 1000/60);
        };
 })();

function tick() {
    window.requestAnimFrame(tick);
}

make sure the interface name starts with capital "W" not "w"

interface Window {
   requestAnimFrame():any;
}

In the calling code use window.requestAnimFrame();. Hope this will solve your problem

another way:

declare var wnd: {
    requestAnimationFrame: any;
    webkitRequestAnimationFrame: any;
    mozRequestAnimationFrame: any;
    oRequestAnimationFrame: any;
    msRequestAnimationFrame: any;
}
var wnd = window;

export var requestAnimFrame = (function () {
    return wnd.requestAnimationFrame ||
           wnd.webkitRequestAnimationFrame ||
           wnd.mozRequestAnimationFrame ||
           wnd.oRequestAnimationFrame ||
           wnd.msRequestAnimationFrame ||
           function (/* function FrameRequestCallback */ callback, /* DOMElement Element */ element) {
               window.setTimeout(callback, 1000 / 60);
           };
})();

The only way that worked for me:

declare global {
    interface Window {
        requestAnimFrame(callback: () => void): any;
        webkitRequestAnimationFrame(callback: () => void): any;
        mozRequestAnimationFrame(callback: () => void): any;
        oRequestAnimationFrame(callback: () => void): any;
    }
}

Window.prototype.requestAnimFrame = function () {
    return window.requestAnimationFrame ||
        window.webkitRequestAnimationFrame ||
        window.mozRequestAnimationFrame ||
        window.oRequestAnimationFrame ||
        function (callback) {
            window.setTimeout(callback, 1000 / 60);
        };
}