tinymce-docs-4x/plugins/directionality.md

layout, title, title_nav, description, keywords, controls

layout	title	title_nav	description	keywords	controls
default	Directionality Plugin	Directionality	Toolbar buttons for setting the left-to-right or right-to-left direction of content.	rtl, ltr, internationalization, internationalisation, localization, localisation, international	toolbar button

This plugin adds directionality controls to the toolbar, enabling TinyMCE to better handle languages written from right to left. It also adds a toolbar button for each of its values, ltr for left-to-right text and rtl for right-to-left text.

Type: String

Possible Values: ltr, rtl

Directionality plugin example

tinymce.init({
  selector: "textarea",  // change this value according to your HTML
  plugins: "directionality",
  toolbar: "ltr rtl"
});