Trigger a click on a 'save' button by pressing cmd/ctrl-s in a textarea (adapt as needed)

textarea-keyboard-save.js

(function() {
  'use strict';

  document.addEventListener('keydown', function(event) {
    var S = 83,
        activeElement = document.activeElement,
        saveButtonId,
        saveButton;

    if ((event.key === S || event.keyCode === S) && (event.metaKey || event.ctrlKey) && activeElement.nodeName === 'TEXTAREA') {
      saveButtonId = activeElement.getAttribute('data-save-with');
      saveButton = document.getElementById(saveButtonId);
      if (saveButton && typeof saveButton.click === 'function') {
        event.preventDefault();
        saveButton.click();
      }
    }
  });
}());