Plugin System

A plugin system for lack of a better term to be used as a basis for confconsole's new modular advanced menu.

The plugin system is a more generic version of what's used in di-live.

Methods

• Di-live method, the di-live method is pretty much as follows.

  1. Get a directory and find all the executable files inside it.
  2. Execute each file in order.

  It's pretty simple and effective but since it does not import or execute the file using exec or execfile, it has no control over the plugins environment and therefor using complex models in between plugins could be difficult.

  A possible solution to this issue to some extent is to pass data through commandline or into config files each plugin could load.

  The other problem is there's no way to do a callback without perhaps making the plugin directory a subdirectory of the plugin framework and make all directories in between python packages (adding a __init__.py) then using relative imports to access the original file. This however would be cause circular references and break pythons garbage collection unless it was implemented in a clever fashion.

  Pros:

  • Incredibly simple to setup
  • Little to no restriction on plugin structure
  • Maintains menu order

  Cons:

  • Rather linear, scripts executed in sequence don't offer a whole lot of fancy menu interaction.
  • No callbacks (or communication other than exitcode)

• Structured python scripts, ran using execfile with a controlled environment. Each python script contains objects that are relevant to whatever it is the plugin is attempting to do. Some suggestions of objects in plugins is as follows:

  • menu_entry (a dictionary containing a name and arbitrarily deep values that represent trees of menu entries. In practice you would probably only create one or two menu entries. If any value in this menu_entry is not a dictionary it must be a callback function.)

    e.g.:

    menu_entry = {
        'advanced_menu': {
            'networking': {
                'test': some_function
            }
        }
    }
    

    would mean when you clicked "Advanced Menu->Networking->Test" it would execute "some_function".

  • onExit (skipped if not defined, if defined handles any cleanup that would otherwise not be correctly closed by python. A database connection for example.)

  Alterations:

  It would also be possible to maintain menu entry order by using lists instead of dictionaries (or perhaps a psuedo dictionary class) that resembles the following:

  menu_entry = [
      [
          'advanced_menu',
          [
              'networking',
              [
                  'test',
                  some_function
              ]
          ]
      ]
  ]
  

  or even something which inferes location by string

  menu_entry = {'advanced_menu/networking/test': some_function}

  Pros:

  • Allows complex interaction between master program and plugins
  • Could maintain menu order
  • Pretty dynamic apart from certain restrictions

  Cons:

  • Maintaining menu order could introduce extra complexity