I use plug-ins for inserting custom HTML (following instructions at (https://github.com/widgetfactory/jce-custom/archive/master.zip. With the 2.7.2 upgrade, the plug-in icons no longer appear in the editor profiles.
Contents of the plug-in editor_plugin.js file are:
(function () {
tinymce.create('tinymce.plugins.RegisterButton', {
init: function (ed, url) {
ed.addButton('register', {
title: 'Register Button',
image: url + '/img/register.png',
onclick: function () {
var html = '<a href="https://www.joomlacontenteditor.net/index.php?option=com_eventbooking&view=upcomingevents&layout=table&id=0&Itemid=143"><img style="display: block; margin-left: auto; margin-right: auto;" src="https://www.joomlacontenteditor.net/images/stories/jevents/register_now_195.png" alt="" /></a>';
ed.execCommand('mceInsertContent', false, html);
}
});
}
});
tinymce.PluginManager.add('register', tinymce.plugins.RegisterButton);
})();
