Insert text at the current caret position of the textarea field that currently has focus

insertAtCaret.js

// Usage:
// insertAtCaret('some text to insert');

(function ($, undefined) {
  
  function insertAtCaret(text) {
    var $focused = $(':focus');
    var focusedCursorPosition = $focused.getCursorPosition();
    var focusedContent = $focused.val();
    var focusedNewContent = focusedContent.substr(0, focusedCursorPosition) + ' ' + string + focusedContent.substr(focusedCursorPosition);
    $focused.val(focusedNewContent);
  }

$.fn.getCursorPosition = function () {
    var el = $(this).get(0);
    var pos = 0;
    if ('selectionStart' in el) {
      pos = el.selectionStart;
    } else if ('selection' in document) {
      el.focus();
      var Sel = document.selection.createRange();
      var SelLength = document.selection.createRange().text.length;
      Sel.moveStart('character', -el.value.length);
      pos = Sel.text.length - SelLength;
    }
    return pos;
}

})(jQuery);