final ! :(

android/app/src/main/AndroidManifest.xml

@@ -7,6 +7,7 @@
     -->
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>    
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/> 
     <uses-permission android:name="android.permission.CAMERA"/>   
     <uses-permission android:name="android.permission.RECORD_AUDIO"/>       
 

lib/config/application.dart

@@ -9,30 +9,43 @@ import 'package:sqflite/sqflite.dart';
 import '../models/Category.dart';
 import '../models/CaptureModel.dart';
 import '../models/Series.dart';
+import '../models/Settings.dart';
 
 class Application {
   static Router router;
   static Database db;
   static bool _dbIsOpened = false;
   static String _databaseName = 'cantonfair.db';
-  static Map<String, dynamic> cache;  
+  static Map<String, dynamic> cache;
   static String databasePath = "";
   static String appDir;
+  static String mainDir;
 
   static String timestamp() => DateTime.now().millisecondsSinceEpoch.toString();
 
   static Future backupDatabase() async {
     await closeDatabase();
     File f = new File(join(databasePath, _databaseName));
-    String newPath = join(databasePath, '${timestamp()}.db');
+    var backup = join(appDir, "Backup");
+    String newPath = join(backup, '${timestamp()}.db');
+    await Directory(backup).create(recursive: true);
     print("Coping to $newPath");
     await f.copy(newPath);
     await openDB();
   }
 
-  static Future initDatabase() async {
-    Directory extPath = await getExternalStorageDirectory();
-    appDir = join(extPath.path, "CantonFair");
+  static Future forceDelete() async {
+    await closeDatabase();
+    File f = new File(join(databasePath, _databaseName));    
+    if (await f.exists()) await f.delete();
+    await openDB();
+  }
+
+  static Future initDatabase() async {        
+    Directory extDir = await getExternalStorageDirectory(); 
+    mainDir = extDir.path;
+    appDir = join(mainDir, "CantonFair");
+    await Directory(appDir).create(recursive: true);
     databasePath = join(appDir, "Database");
     await openDB();
   }
@@ -47,15 +60,9 @@ class Application {
         print("Database opened !");
         _dbIsOpened = true;
 
-        // only on development
-        // print("Droping ${Category.tableName} ...");
-        // await db.execute("DROP TABLE ${Category.tableName};");
-
-        // print("Droping ${Series.tableName} ...");
-        // await db.execute("DROP TABLE ${Series.tableName};");
-
-        // print("Droping ${CaptureModel.tableName} ...");
-        // await db.execute("DROP TABLE ${CaptureModel.tableName};");
+        print("Creating ${Settings.tableName} ...");
+        await db.execute(Settings.dbOnCreate);
+        Settings.db = db;
 
         print("Creating ${CaptureModel.tableName} ...");
         await db.execute(CaptureModel.dbOnCreate);
@@ -71,11 +78,6 @@ class Application {
       },
       onCreate: (Database db, int version) async {
         // only on production
-        print("Creating ${Category.tableName} ...");
-        await db.execute(Category.dbOnCreate);
-
-        print("Creating ${Series.tableName} ...");
-        await db.execute(Series.dbOnCreate);
       },
     );
   }

lib/models/Series.dart

@@ -77,6 +77,7 @@ class Series {
   static Future<Category> getCategoryOfSeriesUUID(uuid,
       {inv: 'desc', order: 'created_at'}) async {
     var series = await getSelectedSeriesByUUID(uuid);
+    if (series == null) return null;
     var result = await db.rawQuery(
         'SELECT * FROM ${Category.tableName} WHERE ${Category.dbUUID} = "${series.categoryUUID}" ORDER BY "$order $inv";');
     List<Category> categories = [];

lib/models/Settings.dart

@@ -0,0 +1,53 @@
+import 'dart:async';
+import 'package:sqflite/sqflite.dart';
+
+class Settings {
+  static Database db;
+
+  static final String dbKey = "key";
+  static final String dbValue = "value";
+
+  static final String tableName = "settings";
+  static final String dbOnCreate = "CREATE TABLE IF NOT EXISTS $tableName ("
+      "${Settings.dbKey} STRING PRIMARY KEY,"
+      "${Settings.dbValue} Text"
+      ")";
+
+  String key;
+  String value;
+
+  Settings({this.key, this.value});
+
+  Settings.fromMap(Map<String, dynamic> map) {
+    this.key = map[dbKey];
+    this.value = map[dbValue];
+  }
+
+  Map<String, dynamic> toMap() {
+    return {
+      dbValue: value,
+      dbKey: key,
+    };
+  }
+
+  static Future<Settings> fetch(String key) async {
+    var result = await db.rawQuery(
+        'SELECT * FROM $tableName WHERE $dbKey = "$key";');
+    List<Settings> items = [];
+    for (Map<String, dynamic> item in result) {
+      items.add(new Settings.fromMap(item));
+    }
+    return items.length > 0 ? items[0] : null;
+  }
+
+  static Future save(Settings item) async {
+    await db.rawInsert(
+        'INSERT OR REPLACE INTO '
+        '$tableName(${Settings.dbKey}, ${Settings.dbValue})'
+        ' VALUES(?, ?)',
+        [
+          item.key,
+          item.value,
+        ]);
+  }
+}