Refactor code search page controller

lib/controllers.dart

@@ -2,6 +2,7 @@ library controllers;
 
 export 'src/controllers/album_detail_controller.dart';
 export 'src/controllers/album_search_controller.dart';
+export 'src/controllers/app_page_controller.dart';
 export 'src/controllers/artist_detail_controller.dart';
 export 'src/controllers/artist_search_controller.dart';
 export 'src/controllers/entry_search_controller.dart';
@@ -11,6 +12,7 @@ export 'src/controllers/favorite_song_controller.dart';
 export 'src/controllers/main_page_controller.dart';
 export 'src/controllers/release_event_detail_controller.dart';
 export 'src/controllers/release_event_search_controller.dart';
+export 'src/controllers/search_page_controller.dart';
 export 'src/controllers/song_detail_controller.dart';
 export 'src/controllers/login_page_controller.dart';
 export 'src/controllers/home_page_controller.dart';

lib/src/controllers/app_page_controller.dart

@@ -0,0 +1,15 @@
+import 'package:get/get.dart';
+import 'package:vocadb_app/utils.dart';
+
+class AppPageController extends GetxController {
+  final initialLoading = true.obs;
+
+  final errorMessage = ''.obs;
+
+  void initialLoadingDone(_) => initialLoading(false);
+
+  void onError(Object err) {
+    initialLoading(false);
+    errorMessage(ErrorUtils.read(err));
+  }
+}

lib/src/controllers/artist_search_controller.dart

@@ -1,85 +1,38 @@
-import 'package:flutter/material.dart';
 import 'package:get/get.dart';
+import 'package:vocadb_app/controllers.dart';
 import 'package:vocadb_app/models.dart';
 import 'package:vocadb_app/repositories.dart';
 import 'package:vocadb_app/services.dart';
 
-class ArtistSearchController extends GetxController {
-  final int maxResults = 50;
-
-  final initialLoading = true.obs;
-
-  /// List of results from search
-  final results = <ArtistModel>[].obs;
-
-  /// Query input string
-  final query = ''.obs;
-
-  /// Set to True when user tap search icon.
-  final openQuery = false.obs;
-
+class ArtistSearchController extends SearchPageController<ArtistModel> {
   /// Filter parameter
   final artistType = ''.obs;
 
   final sort = 'Name'.obs;
 
   final tags = <TagModel>[].obs;
 
-  /// If set to [True], no fetch more data from server. Default is [False].
-  final noFetchMore = false.obs;
-
   final ArtistRepository artistRepository;
 
-  TextEditingController textSearchController;
-
   ArtistSearchController({this.artistRepository});
 
   @override
   void onInit() {
-    initialFetch();
     [artistType, sort, tags]
         .forEach((element) => ever(element, (_) => initialFetch()));
-    debounce(query, (_) => initialFetch(), time: Duration(seconds: 1));
-    textSearchController = TextEditingController();
     super.onInit();
   }
 
-  void initialFetch() {
-    Future.value(noFetchMore(false))
-        .then((_) => fetchApi())
-        .then(verifyShouldFetchMore)
-        .then(results)
-        .then(initialLoadingDone);
-  }
-
-  Future<List<ArtistModel>> fetchApi({int start}) =>
-      artistRepository.findArtists(
+  @override
+  Future<List<ArtistModel>> fetchApi({int start}) => artistRepository
+      .findArtists(
         start: (start == null) ? 0 : start,
         lang: SharedPreferenceService.lang,
         maxResults: maxResults,
         query: query.string,
         artistType: artistType.string,
         sort: sort.string,
         tagIds: tags.toList().map((e) => e.id).join(','),
-      );
-
-  clearQuery() {
-    query('');
-    textSearchController.clear();
-  }
-
-  initialLoadingDone(_) => initialLoading(false);
-
-  List<ArtistModel> verifyShouldFetchMore(List<ArtistModel> items) {
-    if (items == null || items.isEmpty || items.length < maxResults)
-      noFetchMore(true);
-    return items;
-  }
-
-  onReachLastItem() {
-    if (noFetchMore.value) return;
-    fetchApi(start: results.length + 1)
-        .then(verifyShouldFetchMore)
-        .then(results.addAll);
-  }
+      )
+      .catchError(super.onError);
 }

lib/src/controllers/search_page_controller.dart

@@ -0,0 +1,57 @@
+import 'package:flutter/material.dart';
+import 'package:vocadb_app/controllers.dart';
+import 'package:get/get.dart';
+
+abstract class SearchPageController<T> extends AppPageController {
+  final int maxResults = 50;
+
+  /// List of results from search
+  final results = <T>[].obs;
+
+  /// Query input string
+  final query = ''.obs;
+
+  /// Set to True when user tap search icon.
+  final openQuery = false.obs;
+
+  /// If set to [True], no fetch more data from server. Default is [False].
+  final noFetchMore = false.obs;
+
+  TextEditingController textSearchController;
+
+  @override
+  void onInit() {
+    initialFetch();
+    debounce(query, (_) => initialFetch(), time: Duration(seconds: 1));
+    textSearchController = TextEditingController();
+    super.onInit();
+  }
+
+  void initialFetch() {
+    Future.value(noFetchMore(false))
+        .then((_) => fetchApi())
+        .then(verifyShouldFetchMore)
+        .then(results)
+        .then(initialLoadingDone);
+  }
+
+  void clearQuery() {
+    query('');
+    textSearchController.clear();
+  }
+
+  Future<List<T>> fetchApi({int start});
+
+  List<T> verifyShouldFetchMore(List<T> items) {
+    if (items == null || items.isEmpty || items.length < maxResults)
+      noFetchMore(true);
+    return items;
+  }
+
+  onReachLastItem() {
+    if (noFetchMore.value) return;
+    fetchApi(start: results.length + 1)
+        .then(verifyShouldFetchMore)
+        .then(results.addAll);
+  }
+}

lib/src/controllers/song_search_controller.dart

@@ -1,23 +1,11 @@
 import 'package:flutter/material.dart';
 import 'package:get/get.dart';
+import 'package:vocadb_app/controllers.dart';
 import 'package:vocadb_app/models.dart';
 import 'package:vocadb_app/repositories.dart';
 import 'package:vocadb_app/services.dart';
 
-class SongSearchController extends GetxController {
-  final int maxResults = 50;
-
-  final initialLoading = true.obs;
-
-  /// List of results from search
-  final results = <SongModel>[].obs;
-
-  /// Query input string
-  final query = ''.obs;
-
-  /// Set to True when user tap search icon.
-  final openQuery = false.obs;
-
+class SongSearchController extends SearchPageController<SongModel> {
   /// Filter parameter
   final songType = ''.obs;
 
@@ -30,59 +18,26 @@ class SongSearchController extends GetxController {
   /// Filter parameter
   final tags = <TagModel>[].obs;
 
-  /// If set to [True], no fetch more data from server. Default is [False].
-  final noFetchMore = false.obs;
-
   final SongRepository songRepository;
 
-  TextEditingController textSearchController;
-
   SongSearchController({this.songRepository});
 
   @override
   void onInit() {
-    initialFetch();
     [songType, sort, artists, tags]
         .forEach((element) => ever(element, (_) => initialFetch()));
-    debounce(query, (_) => initialFetch(), time: Duration(seconds: 1));
-    textSearchController = TextEditingController();
     super.onInit();
   }
 
-  void initialFetch() {
-    Future.value(noFetchMore(false))
-        .then((_) => fetchApi())
-        .then(verifyShouldFetchMore)
-        .then(results)
-        .then(initialLoadingDone);
-  }
-
-  Future<List<SongModel>> fetchApi({int start}) => songRepository.findSongs(
-      start: (start == null) ? 0 : start,
-      lang: SharedPreferenceService.lang,
-      query: query.string,
-      songType: songType.string,
-      sort: sort.string,
-      artistIds: artists.toList().map((e) => e.id).join(','),
-      tagIds: tags.toList().map((e) => e.id).join(','));
-
-  clearQuery() {
-    query('');
-    textSearchController.clear();
-  }
-
-  initialLoadingDone(_) => initialLoading(false);
-
-  List<SongModel> verifyShouldFetchMore(List<SongModel> items) {
-    if (items == null || items.isEmpty || items.length < maxResults)
-      noFetchMore(true);
-    return items;
-  }
-
-  onReachLastItem() {
-    if (noFetchMore.value) return;
-    fetchApi(start: results.length + 1)
-        .then(verifyShouldFetchMore)
-        .then(results.addAll);
-  }
+  @override
+  Future<List<SongModel>> fetchApi({int start}) => songRepository
+      .findSongs(
+          start: (start == null) ? 0 : start,
+          lang: SharedPreferenceService.lang,
+          query: query.string,
+          songType: songType.string,
+          sort: sort.string,
+          artistIds: artists.toList().map((e) => e.id).join(','),
+          tagIds: tags.toList().map((e) => e.id).join(','))
+      .catchError(super.onError);
 }

lib/src/pages/artist_search_page.dart

@@ -79,11 +79,13 @@ class ArtistSearchPage extends GetView<ArtistSearchController> {
         body: Obx(
           () => (controller.initialLoading.value)
               ? CenterLoading()
-              : ArtistListView(
-                  artists: controller.results.toList(),
-                  onSelect: this._onSelectArtist,
-                  onReachLastItem: controller.onReachLastItem,
-                ),
+              : (controller.errorMessage.string.isNotEmpty)
+                  ? CenterText(controller.errorMessage.string)
+                  : ArtistListView(
+                      artists: controller.results.toList(),
+                      onSelect: this._onSelectArtist,
+                      onReachLastItem: controller.onReachLastItem,
+                      emptyWidget: CenterText('searchResultNotMatched'.tr)),
         ));
   }
 }

lib/src/pages/song_search_page.dart

@@ -58,11 +58,14 @@ class SongSearchPage extends GetView<SongSearchController> {
       body: Obx(
         () => (controller.initialLoading.value)
             ? CenterLoading()
-            : SongListView(
-                songs: controller.results.toList(),
-                onSelect: this._onSelect,
-                onReachLastItem: controller.onReachLastItem,
-              ),
+            : (controller.errorMessage.string.isNotEmpty)
+                ? CenterText(controller.errorMessage.string)
+                : SongListView(
+                    songs: controller.results(),
+                    onSelect: this._onSelect,
+                    onReachLastItem: controller.onReachLastItem,
+                    emptyWidget: CenterText('searchResultNotMatched'.tr),
+                  ),
       ),
       floatingActionButton: FloatingActionButton(
         onPressed: () => AppPages.openPVPlayListPage(controller.results(),

lib/src/utils/error_utils.dart

@@ -0,0 +1,29 @@
+import 'dart:io';
+
+import 'package:dio/dio.dart';
+
+class ErrorUtils {
+  static String read(Object err) {
+    if (err is DioError) {
+      return readDioError(err);
+    }
+
+    return err.toString();
+  }
+
+  static String readDioError(DioError err) {
+    if (err.type == DioErrorType.DEFAULT) {
+      return readDynamicError(err.error);
+    }
+
+    return err.message;
+  }
+
+  static String readDynamicError(dynamic err) {
+    if (err is SocketException) {
+      return err.message;
+    }
+
+    return err.toString();
+  }
+}

lib/src/widgets/artist_list_view.dart

@@ -4,7 +4,12 @@ import 'package:vocadb_app/widgets.dart';
 
 /// A widget for display list of artists
 class ArtistListView extends StatelessWidget {
-  ArtistListView({Key key, this.artists, this.onSelect, this.onReachLastItem})
+  ArtistListView(
+      {Key key,
+      this.artists,
+      this.onSelect,
+      this.onReachLastItem,
+      this.emptyWidget})
       : super(key: key);
 
   /// List of artists to display.
@@ -15,8 +20,15 @@ class ArtistListView extends StatelessWidget {
 
   final Function(ArtistModel) onSelect;
 
+  /// A widget that display when songs is empty
+  final Widget emptyWidget;
+
   @override
   Widget build(BuildContext context) {
+    if (this.artists.isEmpty && this.emptyWidget != null) {
+      return emptyWidget;
+    }
+
     return InfiniteListView(
       itemCount: this.artists.length,
       itemBuilder: (context, index) => ArtistTile.fromEntry(this.artists[index],