feat: persist selected tag & note locally (#1851)

packages/web/src/javascripts/Controllers/Abstract/PersistenceService.ts

@@ -0,0 +1,60 @@
+import { WebApplication } from '@/Application/Application'
+import { ShouldPersistNoteStateKey } from '@/Components/Preferences/Panes/General/Persistence'
+import { ApplicationEvent, InternalEventBus } from '@standardnotes/snjs'
+import { CrossControllerEvent } from '../CrossControllerEvent'
+
+const MasterPersistenceKey = 'master-persistence-key'
+
+export enum PersistenceKey {
+  SelectedItemsController = 'selected-items-controller',
+  NavigationController = 'navigation-controller',
+  ItemListController = 'item-list-controller',
+}
+
+export type MasterPersistedValue = Record<PersistenceKey, unknown>
+
+export class PersistenceService {
+  private unsubAppEventObserver: () => void
+
+  constructor(private application: WebApplication, private eventBus: InternalEventBus) {
+    this.unsubAppEventObserver = this.application.addEventObserver(async (eventName) => {
+      if (!this.application) {
+        return
+      }
+
+      void this.onAppEvent(eventName)
+    })
+  }
+
+  async onAppEvent(eventName: ApplicationEvent) {
+    if (eventName === ApplicationEvent.LocalDataLoaded) {
+      let shouldHydrateState = this.application.getValue(ShouldPersistNoteStateKey)
+
+      if (typeof shouldHydrateState === 'undefined') {
+        this.application.setValue(ShouldPersistNoteStateKey, true)
+        shouldHydrateState = true
+      }
+
+      this.eventBus.publish({
+        type: CrossControllerEvent.HydrateFromPersistedValues,
+        payload: shouldHydrateState ? this.getPersistedValues() : undefined,
+      })
+    }
+  }
+
+  persistValues(values: MasterPersistedValue): void {
+    if (!this.application.isDatabaseLoaded()) {
+      return
+    }
+
+    this.application.setValue(MasterPersistenceKey, values)
+  }
+
+  getPersistedValues(): MasterPersistedValue {
+    return this.application.getValue(MasterPersistenceKey) as MasterPersistedValue
+  }
+
+  deinit() {
+    this.unsubAppEventObserver()
+  }
+}