gum-tool-plugins

MEF plugin discovery in the Gum tool automatically locates and loads internal and external plugins, wiring them into the application through class hierarchies like IPlugin, PluginBase, and PriorityPlugin. This architecture enables dynamic feature extension without modifying the core codebase directly.

To register a new plugin in Gum, implement the required plugin classes and use MEF export attributes for discovery. Handle lifecycle events by subscribing to StartUp for initialization logic and ShutDown for cleanup, ensuring proper resource management within the plugin system.

Plugin origin determines whether a plugin is internal or external, while priority dispatch ensures priority plugins receive events early regardless of their folder location. PriorityPlugin classes leverage this behavior to intercept and handle events before standard plugins execute.

To determine feature ownership in Gum, search for StartUp subscriptions within the internal plugin folders to locate which plugin registers the specific behavior. Internal plugin maps also provide references detailing per-feature behavior and ownership across the system.

You can build external plugins for Gum using the same MEF-based discovery and PluginBase classes as internal plugins. The main difference is their location; external plugins reside outside the internal plugin folders but still follow the same lifecycle, priority dispatch, and event handling rules.