Based on your update, I think you describe a good case for a web application that needs to become modular. You want to be able to easily add new modules (plugins) that give you different functionalities without having to change the application core each time.
Below is a possible solution to your challenge from conceptual point of view. My intention is to help you grasp on the idea and get you started. Keep in mind that it can be simplified further or become much more complex, depending on your needs.
The theoretical side of things
- Plugins/Modules
Each plugin will enable a set of specific features and must be able to work independently from other plugins that are enabled at the moment. All plugins will have to follow a common set of rules and conventions in order to be recognised by your application. This will simplify future maintenance and extension immensely. For example, each plugin should:
Have its own subdirectory under the Plugins/Modules folder that follows a predefined structure (e.g. Backend/Portlets/InstallScripts, etc.)
Use separate storage sandbox in your database, dedicated only to this plugin. Take Kashflow – all tables that are used by the plugin can start with a ksflw_ prefix.
Bring its own partial Frontend view presentation(s) (along with underlying controller logic and model) that implement specific sets of functionality (for example, display pre-selected books in orange border)
Bring its own partial Backend view presentation(s) (along with underlying controller and model) that handle in the site backend (in the case of Kashflow you have portlet visualization that maybe renders a button to manually do synchronization, enables you to schedule one and displays the datetime of the last synchronization made)
Have an installer script, that creates tables, inserts menu items, and initialises hook subscriptions (see next bullet)
Initialize Hooks subscriptions – All subscribed Plugin functions get called whenever a registered event occurs somewhere in the system.
- Core functionality changes
You will need new functionality in your existing application in order to start supporting plugins.
Plugin manager – GUI that allows you to install, remove, enable/disable plugins and allow access to them for your clients.
Partial views manager – allows users to select which partial views of which plugins get displayed in what existing placeholders (this will work in conjunction with hooks)
Placeholders for partial views on pages in the places you want to enable your users to display plugin UI and information
Hooks throughout the application – Whenever "interesting" event happens, the system checks if any plugins are currently subscribed to this event and calls/notifies them, then displays the result. Some examples of events that deserve Hooks might be:
Placeholder rendering – this will trigger all subscribed functionalities to display a frontend/backend partial view
Specific business events – e.g. Whenever new book is being added to the catalogue or is being sold
Administration menu rendering – On this event each installed plugin will select all menu items in the PLUGINNAME_AdminPluginMenu table (the plugin should have created this table at install time) and return all them to the hook for displaying.
I'm sure you'll think of other relevant events, as you know your case best of all.
The practical side of things (based on the second update of the question)
1. Leveraging HMVC for visualisation of partial views (widgets) inside of existing views
As I already stated earlier, Kohana supports HMVC or Hierarchical Model View Controller pattern. This means that you can have a hierarchy of controllers like so (already described in the following question):
![MVC vs HMVC]()
Now, this enables you to easily call controllers from other controllers and even directly from your views! And it works wonders when you need to embed widgets.
You can make a slight modification to boostrap.ini in order to enable Routes like widget_controller/controller_action/action_parameter (this is described in detail in the tutorial I'm giving you below). Then you can have the following code inside your main view template where you want to render your orange book box:
<div class="widget_sidebar">
<?php echo Request::factory('widget_orangebook/display/3')->execute(); ?>
</div>
When executed, this acts as a hook and will invoke the widget_orangebook controller's action_display method with parameter 3 - e.g. you want to show 3 books.
The controller's action will look something like this:
public function action_display ($number_of_books){...}
As a result inside the <div>, you will see the content of the template set by the widget_orangebook controller after execution of the action.
In a sense it gives the illusion of an AJAX partial rendering, but its being executed on the server without the extra call. It is pretty powerful, and I think this is the way to go for the cases you described.
You can see this tutorial to see a detailed description on all the modifications you need to do. It's a bit fancier - it's about rendering multiple widgets in a widget section, but it follows the same logic.
Note that if you insist on using mustache and logicless templates, you can also do this kind of Request call in the controller, set the result to a variable and then pass that variable to your mustache template.
2. Kohana Modules
Kohana supports modules, that allow you to pack up your plugins in an organized way. As you implement more complex plugins this will become important. You can see more on Kohana Modules here.
