Plugins

Wookie's goal is to provide a fast HTTP server while keeping the core as minimal as possible. Wookie does this by only providing the bare essentials for a web server, and letting the rest be built using plugins.

Wookie's core plugins (found in the /core-plugins/ folder) provide a lot of functionality a normal HTTP/app server would. They can be disabled or overridden by your own plugins if you desire different behavior.

The standard behavior for a plugin is to export its publicly available functions to the wookie-plugin-export package. This makes it very easy for an application to :use one package and have access to all of the exported functions for the loaded plugins, without having to explicitely know which package a plugin function is defined.

*enabled-plugins*

This global variable holds a list of enabled plugins. The default:

'(:get :post :multipart :cookie :directory-router)

Loads the core Wookie plugins when load-plugins is called.

*plugin-folders*

This is a list of folders to search for plugins in. The first folders in the list take precedence over later entries, meaning you could push your own plugin directory onto this variable, and the plugins in your directory would take precedence over any plugins in the core directory (any plugins with the same name would load from your directory, not hte core directory).

The default *plugin-folders* value is a list with one entry, the /core-plugins/ directory.

load-plugins (function)

(defun load-plugins (&key ignore-loading-errors (use-quicklisp t)))
  => nil

This function loads looks through all folders in *plugin-folders* and attempts to load any plugins it finds in *enabled-plugins*. It does this by matching the directory name of a plugin with the keyword name of that plugin in *enabled-plugins*.

So let's say :session was added to the *enabled-plugins* list. load-plugins would look for a directory called session/ in each of the folders specified in *plugin-folders*. If it finds a folder called session/, it will attempt to load session/plugin.asd which will be used to load that plugin (along with any of its dependencies).

Plugins are loaded using ASDF, meaning they can use their own :depends-on clause which will be honored.

This function has the ability to ignore any loading errors occuring loading (for instance if a dependency can't be found, that plugin silently fails to load) via :ignore-loading-errors.

load-plugins can also be told to use quicklisp for plugin loading (on by default) which means dependencies can be downloaded automatically if needed.

load-plugins works by loading the ASDF files for each plugin, creating a new system that depends on all the enabled plugins, and loads that system via ASDF.

unload-plugin (function)

(defun unload-plugin (plugin-name))
  => nil

Recursively unloads a plugin and all its dependencies. Note that this won't actually remove the code from the lisp image, but will mark the plugin as unloaded in Wookie's internal plugin registry. Also, unloaded plugins will generally undo any hooks they have into the Wookie system, and will cease to process incoming requests.