Plugin Components

Plugin components are a legacy feature supported for compatibility with plugins created for older versions of the IntelliJ Platform. Plugins using components do not support dynamic loading (the ability to install, update and uninstall plugins without restarting the IDE).

Plugin components are defined using <application-components>, <project-components> and <module-components> tags in a plugin.xml file.

To migrate your code from components to more modern APIs, please use the following guidelines:

• To manage some state or logic that is only needed when the user performs a specific operation, use a Service.
• To store the state of your plugin at the application or project level, use a Service and implement the PersistentStateComponent interface. See Persisting State of Components for details.
• To subscribe to events, use a listener or create an extension for a dedicated extension point (for example, com.intellij.editorFactoryListener) if one exists for the event you need to subscribe to.
• Executing code on application startup should be avoided whenever possible because it slows down startup. Plugin code should only be executed when projects are opened or when the user invokes an action of your plugin. If you can’t avoid this, add a listener subscribing to the AppLifecycleListener topic.
• To execute code when a project is being opened, provide StartupActivity implementation and register an extension for the com.intellij.postStartupActivity or com.intellij.backgroundPostStartupActivity extension point (the latter is supported starting with version 2019.3 of the platform).
• To execute code on project closing or application shutdown, implement the Disposable interface in a Service and place the code in the dispose() method, or use Disposer.register() passing a Project or Application instance as the parent argument.