Filter content by your device's configured languages (#354)

src/state/models/feed-view.ts

@@ -341,7 +341,9 @@ export class FeedModel {
       return [
         FeedTuner.dedupReposts,
         FeedTuner.likedRepliesOnly,
-        FeedTuner.englishOnly,
+        FeedTuner.preferredLangOnly(
+          this.rootStore.preferences.contentLanguages,
+        ),
       ]
     }
     if (this.feedType === 'home') {

src/state/models/root-store.ts

@@ -16,6 +16,7 @@ import {ProfilesViewModel} from './profiles-view'
 import {LinkMetasCache} from './cache/link-metas'
 import {NotificationsViewItemModel} from './notifications-view'
 import {MeModel} from './me'
+import {PreferencesModel} from './ui/preferences'
 import {resetToTab} from '../../Navigation'
 import {ImageSizesCache} from './cache/image-sizes'
 
@@ -33,6 +34,7 @@ export class RootStoreModel {
   log = new LogModel()
   session = new SessionModel(this)
   shell = new ShellUiModel(this)
+  preferences = new PreferencesModel()
   me = new MeModel(this)
   profiles = new ProfilesViewModel(this)
   linkMetas = new LinkMetasCache(this)
@@ -83,6 +85,7 @@ export class RootStoreModel {
       session: this.session.serialize(),
       me: this.me.serialize(),
       shell: this.shell.serialize(),
+      preferences: this.preferences.serialize(),
     }
   }
 
@@ -103,6 +106,9 @@ export class RootStoreModel {
       if (hasProp(v, 'shell')) {
         this.shell.hydrate(v.shell)
       }
+      if (hasProp(v, 'preferences')) {
+        this.preferences.hydrate(v.preferences)
+      }
     }
   }
 

src/state/models/ui/preferences.ts

@@ -0,0 +1,39 @@
+import {makeAutoObservable} from 'mobx'
+import {getLocales} from 'expo-localization'
+import {isObj, hasProp} from 'lib/type-guards'
+
+const deviceLocales = getLocales()
+
+export class PreferencesModel {
+  _contentLanguages: string[] | undefined
+
+  constructor() {
+    makeAutoObservable(this, {}, {autoBind: true})
+  }
+
+  // gives an array of BCP 47 language tags without region codes
+  get contentLanguages() {
+    if (this._contentLanguages) {
+      return this._contentLanguages
+    }
+    return deviceLocales.map(locale => locale.languageCode)
+  }
+
+  serialize() {
+    return {
+      contentLanguages: this._contentLanguages,
+    }
+  }
+
+  hydrate(v: unknown) {
+    if (isObj(v)) {
+      if (
+        hasProp(v, 'contentLanguages') &&
+        Array.isArray(v.contentLanguages) &&
+        typeof v.contentLanguages.every(item => typeof item === 'string')
+      ) {
+        this._contentLanguages = v.contentLanguages
+      }
+    }
+  }
+}