Angular 7 - How does work the HTML5 Fullscreen API ? I've a lot of errors

Question

I use Angular 7 and I would like have a button for put my app in fullscreen. I use the HTML5 Fullscreen API and I\'ve make 2 functions :

Answer 1

You can tell typescript about the methods that you're going to use by using the as keyword to cast the interface of document and document.documentElement.

Like this:

const docElmWithBrowsersFullScreenFunctions = document.documentElement as HTMLElement & {
  mozRequestFullScreen(): Promise;
  webkitRequestFullscreen(): Promise;
  msRequestFullscreen(): Promise;
};

const docWithBrowsersExitFunctions = document as Document & {
  mozCancelFullScreen(): Promise;
  webkitExitFullscreen(): Promise;
  msExitFullscreen(): Promise;
};

Please note that this just prevents compile error and you still should check if the methods exist like you did.

So your methods will be like this:

openfullscreen() {
  // Trigger fullscreen
  const docElmWithBrowsersFullScreenFunctions = document.documentElement as HTMLElement & {
    mozRequestFullScreen(): Promise;
    webkitRequestFullscreen(): Promise;
    msRequestFullscreen(): Promise;
  };

  if (docElmWithBrowsersFullScreenFunctions.requestFullscreen) {
    docElmWithBrowsersFullScreenFunctions.requestFullscreen();
  } else if (docElmWithBrowsersFullScreenFunctions.mozRequestFullScreen) { /* Firefox */
    docElmWithBrowsersFullScreenFunctions.mozRequestFullScreen();
  } else if (docElmWithBrowsersFullScreenFunctions.webkitRequestFullscreen) { /* Chrome, Safari and Opera */
    docElmWithBrowsersFullScreenFunctions.webkitRequestFullscreen();
  } else if (docElmWithBrowsersFullScreenFunctions.msRequestFullscreen) { /* IE/Edge */
    docElmWithBrowsersFullScreenFunctions.msRequestFullscreen();
  }
  this.isfullscreen = true;
}

closefullscreen(){
  const docWithBrowsersExitFunctions = document as Document & {
    mozCancelFullScreen(): Promise;
    webkitExitFullscreen(): Promise;
    msExitFullscreen(): Promise;
  };
  if (docWithBrowsersExitFunctions.exitFullscreen) {
    docWithBrowsersExitFunctions.exitFullscreen();
  } else if (docWithBrowsersExitFunctions.mozCancelFullScreen) { /* Firefox */
    docWithBrowsersExitFunctions.mozCancelFullScreen();
  } else if (docWithBrowsersExitFunctions.webkitExitFullscreen) { /* Chrome, Safari and Opera */
    docWithBrowsersExitFunctions.webkitExitFullscreen();
  } else if (docWithBrowsersExitFunctions.msExitFullscreen) { /* IE/Edge */
    docWithBrowsersExitFunctions.msExitFullscreen();
  }
  this.isfullscreen = false;
}