ckeditor with no toolbar with bootstrap and display Preview by external button in rails

I am about to use CKEditor for post functionality. But I don't need a toolbar for the post functionality. I need to provide a preview of the post that should be HTML version, preview functionality should be done by onkeyup/any button. And preview section will be below the CKEditor.

Image http://grab.by/H5Sk

The mail purpose is to provide a formatted post to the user. If I am using textarea then it returns a string and I can not display as user entered in textarea.