keyboard - Javascript keyDown - no event approach

I'm making game in JavaScript. I have canvas for drawings and game loop. I'd like to make method readKeyboard, in game loop, to check if there is any pressed key. I don't want to attach event to canvas, because it doesn't fit game loop design. Maybe I should attach this event? What is the best solution?

Answer

You could use a library like KeyboardJS, which will listen the keyboard events and fill an array with the active keys.

In your gameloop:

var activeKeys = KeyboardJS.activeKeys();
if (activeKeys.indexOf(84) > -1) {
  // key pressed

}

I also made my own library, which is lighter but clearly less complete than KeyboardJS.