tsdom/src/event/delegate.ts

Fast, lightweight JavaScript DOM manipulation utility

import { Instance } from '../index';

/* -----------------------------------
 *
 * Delegate
 *
 * -------------------------------- */

function delegate(
   scope: HTMLElement,
   query: string,
   cb: (ev: Event, el: HTMLElement) => void
) {
   return (ev: Event) => {
      const $elements = new Instance(query, scope);

      let el = null;
      let hit = false;

      $elements.each(_el => {
         let test = ev.target as any;

         if (test === _el) {
            hit = true;
            el = test;

            return;
         }

         while (test && test !== scope) {
            test = test.parentNode;

            if (test === _el) {
               hit = true;
               el = test;
            }
         }
      });

      if (hit) {
         cb(ev, el);
      }
   };
}

/* -----------------------------------
 *
 * Export
 *
 * -------------------------------- */

export { delegate };