A lightweight web component that traps focus within a DOM node
_{A focus trap ensures that tab and shift + tab keys will cycle through the focus trap's tabbable elements but not leave the focus trap. This is great for making accessible modals. Go here to see a demo https://appnest-demo.firebaseapp.com/focus-trap/.}

• Does one things very very well - it traps the focus!
• Pierces through the shadow roots when looking for focusable elements.
• Works right out of the box (just add it to your markup)
• Created using only vanilla js - no dependencies and framework agnostic!

npm i @a11y/focus-trap

Import @a11y/focus-trap somewhere in your code and you're ready to go! Simply add the focus trap to your html and it'll be working without any more effort from your part.

<focus-trap>
  <button>Focus 1</button>
  <button>Focus 2</button>
  <button>Focus 3</button>
  <button>Focus 4</button>
  <button>Focus 5</button>
</focus-trap>

The focus-trap element implements the following interface.

interface IFocusTrap {
  // Returns whether or not the focus trap is inactive.
  inactive: boolean;

  // Returns whether the focus trap currently has focus.
  readonly focused: boolean;

  // Focuses the first focusable element in the focus trap.
  focusFirstElement: (() => void);

  // Focuses the last focusable element in the focus trap.
  focusLastElement: (() => void);

  // Returns a list of the focusable children found within the element.
  getFocusableElements: (() => HTMLElement[]);
}

Licensed under MIT.