This article explains the basics of creating a plugin for the Contao CMS using the Contao Viewer plugin as an example. You can download the completed plugin from Contao.
Requirements Contao CMS PHP 5.3 JavaScript PreparationTo create a GroupDocs Viewer plugin for Contao CMS: Install Contao CMS. The installation of this CMS is a simple. Allow GroupDocs to appear go to Admin > Setting > Security settings > Allowed HTML tags and just add at the end....take a look at the code we inserted. The first line # if (!defined('TL\_ROOT'))...//This function is describe an insertion of plugin info to the CMS...