Merge pull request #17470 from strapi/chore/route-loader-comment

Chore: Add code comment for plugin initializer

packages/core/admin/admin/src/components/PluginsInitializer/index.js

@@ -18,6 +18,29 @@ const PluginsInitializer = () => {
     (plugin) => plugins[plugin].isReady === false
   );
 
+  /**
+   *
+   * I have spent some time trying to understand what is happening here, and wanted to
+   * leave that knowledge for my future me:
+   *
+   * `initializer` is an undocumented property of the `registerPlugin` API. At the time
+   * of writing it seems only to be used by the i18n plugin.
+   *
+   * How does it work?
+   *
+   * Every plugin that has an `initializer` component defined, receives the
+   * `setPlugin` function as a component prop. In the case of i18n the plugin fetches locales
+   * first and calls `setPlugin` with `pluginId` once they are loaded, which then triggers the
+   * reducer of the admin app defined above.
+   *
+   * Once all plugins are set to `isReady: true` the app renders.
+   *
+   * This API is used to block rendering of the admin app. We should remove that in v5 completely
+   * and make sure plugins can inject data into the global store before they are initialized, to avoid
+   * having a new prop-callback based communication channel between plugins and the core admin app.
+   *
+   */
+
   if (hasApluginNotReady) {
     const initializers = Object.keys(plugins).reduce((acc, current) => {
       const InitializerComponent = plugins[current].initializer;