A plugin system architecture based on Composer. This is a proof of concept to test how installing plugins would work.

Composer adds basic functionality that makes life easier!

• Versions constraints making installing and updating easy.
• PHP extensions are checked for existance.
• Possibility to add dependencies to other plugins (composer packages).
• Deployment architecture via custom repositories and Packagist.

• Installing might take a while so the user must wait or installing would have to be done in a queued job (e.g. Beanstalkd).
• The HOME directory must be accessible else composer won't run.
• You would have to maintain a list of all plugins that are installed. You can't parse the composer.json to lookup which plugins are installed because it also contains dependencies for your application.
• It would be possible to update the application dependencies since there is no way of tracking which dependencies are plugins and which one are application dependencies.