Cache user information

lib/enums/user_page_visibility.dart

@@ -3,3 +3,12 @@
 /// @author Pierre HUBERT
 
 enum UserPageVisibility { PRIVATE, PUBLIC, OPEN }
+
+/// Find the visibility level matching a string
+UserPageVisibility userPageVisibilityFromString(String str) {
+  for (int i = 0; i < UserPageVisibility.values.length; i++)
+    if (UserPageVisibility.values[i].toString() == str)
+      return UserPageVisibility.values[i];
+
+  throw "$str is not a valid user page visibility level!";
+}

lib/helpers/database/database_contract.dart

@@ -0,0 +1,20 @@
+/// Database contract
+///
+/// @author Pierre HUBERT
+
+/// Main information
+class DatabaseContract {
+  static const DATABASE_VERSION = 1;
+  static const DATABASE_FILE_NAME = "database.sqlite";
+}
+
+/// User table contract
+abstract class UserTableContract {
+  static const TABLE_NAME = "users";
+  static const C_ID = "id";
+  static const C_FIRST_NAME = "first_name";
+  static const C_LAST_NAME = "last_name";
+  static const C_VISIBILITY  = "visibility";
+  static const C_VIRTUAL_DIRECTORY = "virtual_directory";
+  static const C_ACCOUNT_IMAGE_URL = "account_image_url";
+}

lib/helpers/database/database_helper.dart

@@ -0,0 +1,53 @@
+import 'package:comunic/helpers/database/database_contract.dart';
+import 'package:path/path.dart';
+import 'package:sqflite/sqflite.dart';
+
+/// Database Helper
+///
+/// Manage the connection to the local SQLite database
+///
+/// @author Pierre HUBERT
+
+abstract class DatabaseHelper {
+  static Database _db;
+
+  /// Open the database
+  static Future<void> open() async {
+    if (_db != null && _db.isOpen) return;
+
+    var databasePath = await getDatabasesPath();
+    _db = await openDatabase(
+        join(databasePath, DatabaseContract.DATABASE_FILE_NAME),
+        version: DatabaseContract.DATABASE_VERSION,
+        onUpgrade: _performDatabaseUpdate,
+        onCreate: _initializeDatabase);
+  }
+
+  /// Get a database instance
+  static Future<Database> get() async {
+    await open();
+    return _db;
+  }
+
+  /// Perform database update
+  ///
+  /// Currently : delete all the database tables and initialize it again
+  static Future<void> _performDatabaseUpdate(
+      Database db, int oldVersion, int newVersion) async {
+    //Initialize database again
+    await _initializeDatabase(db, newVersion);
+  }
+
+  /// Initialize the database
+  static Future<void> _initializeDatabase(Database db, int version) async {
+    //Create users table
+    await db.execute("CREATE TABLE ${UserTableContract.TABLE_NAME} ("
+        "${UserTableContract.C_ID} INTEGER PRIMARY KEY, "
+        "${UserTableContract.C_FIRST_NAME} TEXT, "
+        "${UserTableContract.C_LAST_NAME} TEXT, "
+        "${UserTableContract.C_VISIBILITY} TEXT,"
+        "${UserTableContract.C_VIRTUAL_DIRECTORY} TEXT,"
+        "${UserTableContract.C_ACCOUNT_IMAGE_URL} TEXT"
+        ")");
+  }
+}

lib/helpers/database/users_database_helper.dart

@@ -0,0 +1,62 @@
+import 'package:comunic/models/user.dart';
+
+import 'database_contract.dart';
+import 'database_helper.dart';
+
+/// User database helper
+///
+/// @author Pierre HUBERT
+
+class UsersDatabaseHelper {
+  /// Insert a user in the database
+  Future<void> _insertDB(User user) async {
+    await (await DatabaseHelper.get())
+        .insert(UserTableContract.TABLE_NAME, user.toMap());
+  }
+
+  /// Update a user in the database
+  Future<void> _updateDB(User user) async {
+    await (await DatabaseHelper.get()).update(
+      UserTableContract.TABLE_NAME,
+      user.toMap(),
+      where: "${UserTableContract.C_ID} = ?",
+      whereArgs: [user.id],
+    );
+  }
+
+  /// Get a user from the database with a specified [id]
+  ///
+  /// Returns null if none found
+  Future<User> get(int id) async {
+    List<Map> maps = await (await DatabaseHelper.get()).query(
+      UserTableContract.TABLE_NAME,
+      where: '${UserTableContract.C_ID} = ?',
+      whereArgs: [id],
+    );
+
+    if (maps.length > 0) return User.fromMap(maps[0]);
+
+    return null;
+  }
+
+  /// Check out whether a user information specified with its [id] is present
+  /// or not in the local database
+  Future<bool> has(int id) async {
+    return (await get(id)) != null;
+  }
+
+  /// Insert or update information about a user (depends of the presence
+  /// of previous user information in the database
+  Future<void> insertOrUpdate(User user) async {
+    if (await has(user.id))
+      await _updateDB(user);
+    else
+      await _insertDB(user);
+  }
+
+  /// Insert or update an important amount of user information
+  Future<void> insertOrUpdateAll(List<User> list) async {
+    for(int i = 0; i < list.length; i++)
+      await insertOrUpdate(list[i]);
+  }
+}

lib/helpers/users_helper.dart

@@ -1,4 +1,5 @@
 import 'package:comunic/enums/user_page_visibility.dart';
+import 'package:comunic/helpers/database/users_database_helper.dart';
 import 'package:comunic/lists/users_list.dart';
 import 'package:comunic/models/api_request.dart';
 import 'package:comunic/models/user.dart';
@@ -10,6 +11,9 @@ import 'package:comunic/models/user.dart';
 /// @author Pierre HUBERT
 
 class UsersHelper {
+
+  final UsersDatabaseHelper _usersDatabaseHelper = UsersDatabaseHelper();
+
   /// Download information about some given users ID
   ///
   /// Return the list of users information in case of success, null in case of
@@ -42,6 +46,9 @@ class UsersHelper {
               ),
         );
 
+    // Save the list
+    _usersDatabaseHelper.insertOrUpdateAll(list);
+
     return list;
   }
 }

lib/main.dart

@@ -1,4 +1,5 @@
 import 'package:comunic/helpers/account_helper.dart';
+import 'package:comunic/helpers/database/database_helper.dart';
 import 'package:comunic/models/config.dart';
 import 'package:comunic/ui/routes/home_route.dart';
 import 'package:comunic/ui/routes/login_route.dart';
@@ -20,6 +21,9 @@ void main() {
       serviceName: "ComunicFlutter",
       serviceToken: "G9sZCBmb3IgVWJ1bnR1CkNvbW1lbnRbbmVdPeCkieCkrOCkq"));
 
+  // Connect to database
+  DatabaseHelper.open();
+
   runApp(ComunicApplication());
 }
 

lib/models/user.dart

@@ -1,4 +1,5 @@
 import 'package:comunic/enums/user_page_visibility.dart';
+import 'package:comunic/helpers/database/database_contract.dart';
 import 'package:meta/meta.dart';
 
 /// Single user information
@@ -28,4 +29,24 @@ class User {
 
   /// Get user full name
   String get fullName => firstName + " " + lastName;
+
+  Map<String, dynamic> toMap() {
+    return {
+      UserTableContract.C_ID: id,
+      UserTableContract.C_FIRST_NAME: firstName,
+      UserTableContract.C_LAST_NAME: lastName,
+      UserTableContract.C_VISIBILITY: pageVisibility.toString(),
+      UserTableContract.C_VIRTUAL_DIRECTORY: virtualDirectory,
+      UserTableContract.C_ACCOUNT_IMAGE_URL: accountImageURL,
+    };
+  }
+
+  User.fromMap(Map<String, dynamic> map)
+      : this.id = map[UserTableContract.C_ID],
+        this.firstName = map[UserTableContract.C_FIRST_NAME],
+        this.lastName = map[UserTableContract.C_LAST_NAME],
+        this.pageVisibility =
+            userPageVisibilityFromString(map[UserTableContract.C_VISIBILITY]),
+        this.virtualDirectory = map[UserTableContract.C_VIRTUAL_DIRECTORY],
+        this.accountImageURL = map[UserTableContract.C_ACCOUNT_IMAGE_URL];
 }

pubspec.lock

@@ -100,6 +100,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.5.4"
+  sqflite:
+    dependency: "direct main"
+    description:
+      name: sqflite
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.5"
   stack_trace:
     dependency: transitive
     description:
@@ -121,6 +128,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.0.4"
+  synchronized:
+    dependency: transitive
+    description:
+      name: synchronized
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.0"
   term_glyph:
     dependency: transitive
     description:
@@ -151,4 +165,4 @@ packages:
     version: "2.0.8"
 sdks:
   dart: ">=2.1.0 <3.0.0"
-  flutter: ">=0.1.4 <2.0.0"
+  flutter: ">=1.2.1 <2.0.0"

pubspec.yaml

@@ -27,6 +27,9 @@ dependencies:
   # Preferences are useful for a lot of things (ex: login tokens)
   shared_preferences: ^0.5.2
 
+  # SQLite database is used for caching
+  sqflite: ^1.1.5
+
 dev_dependencies:
   flutter_test:
     sdk: flutter