Auto RTL support for gitter.im

autoRtlForGitter.user.js

// ==UserScript==
// @name        RTL For Gitter
// @namespace   Sheman
// @include     *gitter.im/*
// @version     1.2.5
// @grant       none
// @description     This Script add "Auto RTL Support" the the gitter.im website so users like Persians could use it better than before.
// @Author      Eman Amini
// ==/UserScript==
var css = ".rtl {direction: rtl;}",
    head = document.head || document.getElementByTagName("head")[0],
    style = document.createElement("style");
style.type = "text/css";
if (style.styleSheet)
{
  style.stylesheet.cssText = css;
} 
else 
{
  style.appendChild(document.createTextNode(css));
}
head.appendChild(style);

function checkRtl( character )
{
      var RTL = new RegExp('[آ-ی]', 'g');


    if( RTL.test(character))
    {
          return true;
    } else
    {
          return false;
    }

}

function init()
{
      var chatText = document.getElementsByClassName("chat-item__text");
      for (var i = 0; i < chatText.length; i++)
      {
            var eachLine = chatText[i].innerHTML;
            var firstChar = eachLine.charAt(0);
            if (checkRtl(firstChar))
            {
                  chatText[i].classList.add('rtl');
                  //chatText[i].setAttribute("class", "rtl");
            }

      }
      var chatBox = document.getElementById("chat-input-textarea");
      
            var eachLineBox = chatBox.innerHTML;
            var firstChar = eachLineBox.charAt(0);
            if (checkRtl(firstChar))
            {
                  chatText[i].classList.add('rtl');
                  //chatText[i].setAttribute("class", "rtl");
            }

      
}

//setTimeout(init, 5000);
window.onload = init;



// select the target node
var target = document.getElementById('chat-container');

// create an observer instance
var observer = new MutationObserver(function(mutations) 
{
  mutations.forEach(function(mutation) 
  {
     init();
  });
});

// configuration of the observer:
var config = { attributes: true, childList: true, characterData: true };

// pass in the target node, as well as the observer options
observer.observe(target, config);

document.documentElement.onkeyup = checkMe;

function checkMe()
{
      var chatMe = document.getElementById("chat-input-textarea").value;
      var firstChatMeChar = chatMe.charAt(0);
      if (checkRtl(firstChatMeChar)) 
      {
            var elementID = document.getElementById("chat-input-box-region");
            elementID.classList.add("rtl");
      }
      else 
      {
            document.getElementById("chat-input-box-region").className = "";
            document.getElementById("chat-input-box-region").className = "chat-input-box__region";
      }

}