Start conversation upgrade

lib/constants.dart

@@ -0,0 +1,6 @@
+/// Comunic mobile constants
+///
+/// @author Pierre Hubert
+
+/// Data serialisation directory
+const SERIALIZATION_DIRECTORY = "serialization";

lib/helpers/conversations_helper.dart

@@ -1,5 +1,5 @@
-import 'package:comunic/helpers/database/conversation_messages_database_helper.dart';
+import 'package:comunic/helpers/serialization/conversation_message_serialization_helper.dart';
-import 'package:comunic/helpers/database/conversations_database_helper.dart';
+import 'package:comunic/helpers/serialization/conversations_serialization_helper.dart';
 import 'package:comunic/helpers/users_helper.dart';
 import 'package:comunic/helpers/websocket_helper.dart';
 import 'package:comunic/lists/conversation_messages_list.dart';
@@ -9,9 +9,12 @@ import 'package:comunic/lists/users_list.dart';
 import 'package:comunic/models/api_request.dart';
 import 'package:comunic/models/api_response.dart';
 import 'package:comunic/models/conversation.dart';
+import 'package:comunic/models/conversation_member.dart';
 import 'package:comunic/models/conversation_message.dart';
 import 'package:comunic/models/displayed_content.dart';
+import 'package:comunic/models/new_conversation.dart';
 import 'package:comunic/models/new_conversation_message.dart';
+import 'package:comunic/models/new_conversation_settings.dart';
 import 'package:comunic/models/unread_conversation.dart';
 import 'package:comunic/utils/account_utils.dart';
 import 'package:meta/meta.dart';
@@ -25,20 +28,16 @@ enum SendMessageResult { SUCCESS, MESSAGE_REJECTED, FAILED }
 class ConversationsHelper {
   static final _registeredConversations = Map<int, int>();
 
-  final ConversationsDatabaseHelper _conversationsDatabaseHelper =
-      ConversationsDatabaseHelper();
-  final ConversationMessagesDatabaseHelper _conversationMessagesDatabaseHelper =
-      ConversationMessagesDatabaseHelper();
-
   /// Create a new conversation
   ///
   /// Return the ID of the newly created conversation or -1 in case of failure
-  Future<int> createConversation(Conversation settings) async {
+  Future<int> createConversation(NewConversation settings) async {
     final response =
         await APIRequest(uri: "conversations/create", needLogin: true, args: {
-      "name": settings.hasName ? settings.name : "false",
+      "name": settings.name ?? "",
-      "follow": settings.following ? "true" : "false",
+      "follow": settings.follow ? "true" : "false",
       "users": settings.members.join(","),
+      "color": settings.color ?? ","
     }).addBool("canEveryoneAddMembers", settings.canEveryoneAddMembers).exec();
 
     if (response.code != 200) return -1;
@@ -48,72 +47,51 @@ class ConversationsHelper {
 
   /// Update an existing conversation
   ///
-  /// Returns a boolean depending of the success of the operation
+  /// Throws in case of failure
-  Future<bool> updateConversation(Conversation settings) async {
+  Future<void> updateConversation(NewConversationsSettings settings) async {
-    final request =
+    final request = APIRequest.withLogin("conversations/updateSettings")
-        APIRequest(uri: "conversations/updateSettings", needLogin: true, args: {
+        .addInt("conversationID", settings.convID)
-      "conversationID": settings.id.toString(),
+        .addBool("following", settings.following);
-      "following": settings.following ? "true" : "false"
-    });
 
-    if (settings.isOwner || settings.canEveryoneAddMembers)
+    // Update conversation settings
-      request.addString("members", settings.members.join(","));
+    if (settings.isComplete)
+      request
+          .addString("name", settings.name ?? "")
+          .addBool("canEveryoneAddMembers", settings.canEveryoneAddMembers)
+          .addString("color", settings.color ?? "");
 
-    // Update all conversation settings, if possible
+    await request.execWithThrow();
-    if (settings.isOwner) {
-      request.addString("name", settings.hasName ? settings.name : "false");
-      request.addBool("canEveryoneAddMembers", settings.canEveryoneAddMembers);
-    }
 
-    final response = await request.exec();
+    // Delete old conversation entry from the database
-
+    await ConversationsSerializationHelper()
-    if (response.code != 200) return false;
+        .removeElement((t) => t.id == settings.convID);
-
-    //Delete old conversation entry from the database
-    await _conversationsDatabaseHelper.delete(settings.id);
-
-    // Success
-    return true;
   }
 
   /// Delete a conversation specified by its [id]
-  Future<bool> deleteConversation(int id) async {
+  Future<void> deleteConversation(int id) async =>
-    final response = await APIRequest(
+      await APIRequest.withLogin("conversations/delete")
-      uri: "conversations/delete",
+          .addInt("conversationID", id)
-      needLogin: true,
+          .execWithThrow();
-      args: {
-        "conversationID": id.toString(),
-      },
-    ).exec();
-
-    return response.code == 200;
-  }
 
   /// Download the list of conversations from the server
+  ///
+  /// Throws an exception in case of failure
   Future<ConversationsList> downloadList() async {
     final response =
-        await APIRequest(uri: "conversations/getList", needLogin: true).exec();
+        await APIRequest.withLogin("conversations/getList").execWithThrow();
 
-    if (response.code != 200) return null;
+    ConversationsList list = ConversationsList();
+    response.getArray().forEach((f) => list.add(apiToConversation(f)));
 
-    try {
+    // Update the database
-      ConversationsList list = ConversationsList();
+    await ConversationsSerializationHelper().setList(list);
-      response.getArray().forEach((f) => list.add(apiToConversation(f)));
 
-      // Update the database
+    return list;
-      await _conversationsDatabaseHelper.clearTable();
-      await _conversationsDatabaseHelper.insertAll(list);
-
-      return list;
-    } on Exception catch (e) {
-      print(e.toString());
-      return null;
-    }
   }
 
   /// Get the local list of conversations
   Future<ConversationsList> getCachedList() async {
-    final list = await _conversationsDatabaseHelper.getAll();
+    final list = await ConversationsSerializationHelper().getList();
     list.sort();
     return list;
   }
@@ -124,41 +102,31 @@ class ConversationsHelper {
       final response = await APIRequest(
           uri: "conversations/getInfoOne",
           needLogin: true,
-          args: {"conversationID": id.toString()}).exec();
+          args: {"conversationID": id.toString()}).execWithThrow();
-
-      if (response.code != 200) return null;
 
       final conversation = apiToConversation(response.getObject());
-      _conversationsDatabaseHelper.insertOrUpdate(conversation);
+
+      await ConversationsSerializationHelper()
+          .insertOrReplaceElement((c) => c.id == conversation.id, conversation);
       return conversation;
-    } on Exception catch (e) {
+    } on Exception catch (e, s) {
-      print(e.toString());
+      print("Could not get information about a single conversation ! $e => $s");
-      print("Could not get information about a single conversation !");
       return null;
     }
   }
 
-  /// Get information about a single conversation. If [force] is set to false,
+  /// Get information about a conversation. If [force] is set to false, a
   /// cached version of the conversation will be used, else it will always get
-  /// the information from the server
+  /// the information from the server. The method throws an [Exception] in
-  Future<Conversation> getSingle(int id, {bool force = false}) async {
-    if (force || !await _conversationsDatabaseHelper.has(id))
-      return await _downloadSingle(id);
-    else
-      return _conversationsDatabaseHelper.get(id);
-  }
-
-  /// Get information about a conversation. The method throws an [Exception] in
   /// case of failure
   ///
   /// Return value of this method is never null.
-  Future<Conversation> getSingleOrThrow(int id, {bool force = false}) async {
+  Future<Conversation> getSingle(int id, {bool force = false}) async {
-    final conv = await this.getSingle(id, force: force);
+    if (force ||
-
+        !await ConversationsSerializationHelper().any((c) => c.id == id))
-    if (conv == null)
+      return await _downloadSingle(id);
-      throw Exception("Could not get information about the conversation!");
+    else
-
+      return await ConversationsSerializationHelper().get(id);
-    return conv;
   }
 
   /// Get the name of a [conversation]. This requires information
@@ -170,9 +138,9 @@ class ConversationsHelper {
     String name = "";
     int count = 0;
     for (int i = 0; i < 3 && i < conversation.members.length; i++)
-      if (conversation.members[i] != userID()) {
+      if (conversation.members[i].userID != userID()) {
         name += (count > 0 ? ", " : "") +
-            users.getUser(conversation.members[i]).fullName;
+            users.getUser(conversation.members[i].userID).fullName;
         count++;
       }
 
@@ -184,6 +152,8 @@ class ConversationsHelper {
   /// Search and return a private conversation with a given [userID]. If such
   /// conversation does not exists, it is created if [allowCreate] is set to
   /// true
+  ///
+  /// Throws an exception in case of failure
   Future<int> getPrivate(int userID, {bool allowCreate = true}) async {
     final response = await APIRequest(
       uri: "conversations/getPrivate",
@@ -192,17 +162,10 @@ class ConversationsHelper {
         "otherUser": userID.toString(),
         "allowCreate": allowCreate.toString()
       },
-    ).exec();
+    ).execWithThrow();
-
-    if (response.code != 200) return null;
 
     // Get and return conversation ID
-    try {
+    return int.parse(response.getObject()["conversationsID"][0].toString());
-      return int.parse(response.getObject()["conversationsID"][0].toString());
-    } catch (e) {
-      e.toString();
-      return null;
-    }
   }
 
   /// Asynchronously get the name of the conversation
@@ -210,15 +173,13 @@ class ConversationsHelper {
   /// Unlike the synchronous method, this method does not need information
   /// about the members of the conversation
   ///
-  /// Returns null in case of failure
+  /// Throws an exception in case of failure
   static Future<String> getConversationNameAsync(
       Conversation conversation) async {
     if (conversation.hasName) return conversation.name;
 
     //Get information about the members of the conversation
-    final members = await UsersHelper().getUsersInfo(conversation.members);
+    final members = await UsersHelper().getList(conversation.membersID);
-
-    if (members == null) return null;
 
     return ConversationsHelper.getConversationName(conversation, members);
   }
@@ -226,14 +187,18 @@ class ConversationsHelper {
   /// Turn an API entry into a [Conversation] object
   static Conversation apiToConversation(Map<String, dynamic> map) {
     return Conversation(
-        id: map["ID"],
+        id: map["id"],
-        ownerID: map["ID_owner"],
+        lastActivity: map["last_activity"],
-        lastActive: map["last_active"],
+        name: map["name"],
-        name: map["name"] == false ? null : map["name"],
+        color: map["color"],
-        following: map["following"] == 1,
+        logoURL: map["logo"],
-        sawLastMessage: map["saw_last_message"] == 1,
+        groupID: map["group_id"],
-        members: List<int>.from(map["members"]),
+        members: map["members"]
-        canEveryoneAddMembers: map["canEveryoneAddMembers"],
+            .cast<Map<String, dynamic>>()
+            .map(apiToConversationMember)
+            .toList()
+            .cast<ConversationMember>(),
+        canEveryoneAddMembers: map["can_everyone_add_members"],
         callCapabilities: map["can_have_video_call"]
             ? CallCapabilities.VIDEO
             : (map["can_have_call"]
@@ -242,10 +207,21 @@ class ConversationsHelper {
         isHavingCall: map["has_call_now"]);
   }
 
+  static ConversationMember apiToConversationMember(Map<String, dynamic> map) =>
+      ConversationMember(
+        userID: map["user_id"],
+        lastMessageSeen: map["last_message_seen"],
+        lastAccessTime: map["last_access"],
+        following: map["following"],
+        isAdmin: map["is_admin"],
+      );
+
   /// Parse a list of messages given by the server
+  ///
+  /// Throws an exception in case of failure
   Future<ConversationMessagesList> _parseConversationMessageFromServer(
       int conversationID, APIResponse response) async {
-    if (response.code != 200) return null;
+    response.assertOk();
 
     // Parse the response of the server
     ConversationMessagesList list = ConversationMessagesList();
@@ -256,7 +232,8 @@ class ConversationsHelper {
     });
 
     // Save messages in the cache
-    _conversationMessagesDatabaseHelper.insertOrUpdateAll(list);
+    await ConversationsMessagesSerializationHelper(conversationID)
+        .insertOrReplaceAll(list);
 
     return list;
   }
@@ -265,6 +242,8 @@ class ConversationsHelper {
   ///
   /// Set [lastMessageID] to 0 to specify that we do not have any message of the
   /// conversation yet or another value else
+  ///
+  /// Throws an exception in case of failure
   Future<ConversationMessagesList> _downloadNewMessagesSingle(
       int conversationID,
       {int lastMessageID = 0}) async {
@@ -275,26 +254,26 @@ class ConversationsHelper {
         args: {
           "conversationID": conversationID.toString(),
           "last_message_id": lastMessageID.toString()
-        }).exec();
+        }).execWithThrow();
 
     return await _parseConversationMessageFromServer(conversationID, response);
   }
 
   /// Get older messages for a given conversation from an online source
+  ///
+  /// Throws in case of failure
   Future<ConversationMessagesList> getOlderMessages({
     @required int conversationID,
     @required int oldestMessagesID,
     int limit = 15,
   }) async {
     // Perform the request online
-    final response = await APIRequest(
+    final response =
-        uri: "conversations/get_older_messages",
+        await APIRequest.withLogin("conversations/get_older_messages", args: {
-        needLogin: true,
+      "conversationID": conversationID.toString(),
-        args: {
+      "oldest_message_id": oldestMessagesID.toString(),
-          "conversationID": conversationID.toString(),
+      "limit": limit.toString()
-          "oldest_message_id": oldestMessagesID.toString(),
+    }).execWithThrow();
-          "limit": limit.toString()
-        }).exec();
 
     return await _parseConversationMessageFromServer(conversationID, response);
   }
@@ -304,6 +283,8 @@ class ConversationsHelper {
   /// If [lastMessageID] is set to 0 then we retrieve the last messages of
   /// the conversation.
   /// Otherwise [lastMessageID] contains the ID of the last known message
+  ///
+  /// Throws in case of failure
   Future<ConversationMessagesList> getNewMessages(
       {@required int conversationID,
       int lastMessageID = 0,
@@ -312,16 +293,8 @@ class ConversationsHelper {
       return await _downloadNewMessagesSingle(conversationID,
           lastMessageID: lastMessageID);
     else
-      return await _conversationMessagesDatabaseHelper
+      return await ConversationsMessagesSerializationHelper(conversationID)
-          .getAllMessagesConversations(conversationID,
+          .getList();
-              lastMessageID: lastMessageID);
-  }
-
-  /// Get a single conversation message from the local database
-  ///
-  /// Returns the message if found or null in case of failure
-  Future<ConversationMessage> getSingleMessageFromCache(int messageID) async {
-    return await _conversationMessagesDatabaseHelper.get(messageID);
   }
 
   /// Send a new message to the server
@@ -353,14 +326,13 @@ class ConversationsHelper {
   }
 
   /// Save / Update a  message into the database
-  Future<void> saveMessage(ConversationMessage msg) async {
+  Future<void> saveMessage(ConversationMessage msg) async =>
-    await _conversationMessagesDatabaseHelper.insertOrUpdate(msg);
+      await ConversationsMessagesSerializationHelper(msg.convID)
-  }
+          .insertOrReplace(msg);
 
   /// Remove a message from the database
-  Future<void> removeMessage(int msgID) async {
+  Future<void> removeMessage(ConversationMessage msg) async =>
-    await _conversationMessagesDatabaseHelper.delete(msgID);
+      await ConversationsMessagesSerializationHelper(msg.convID).remove(msg);
-  }
 
   /// Update a message content
   Future<bool> updateMessage(int id, String newContent) async {
@@ -397,11 +369,8 @@ class ConversationsHelper {
 
     return UnreadConversationsList()
       ..addAll(list.map((f) => UnreadConversation(
-            id: f["id"],
+            conv: apiToConversation(f["conv"]),
-            convName: f["conv_name"],
+            message: apiToConversationMessage(f["message"]),
-            lastActive: f["last_active"],
-            userID: f["userID"],
-            message: f["message"],
           )));
   }
 
@@ -432,13 +401,38 @@ class ConversationsHelper {
   static ConversationMessage apiToConversationMessage(
     Map<String, dynamic> map,
   ) {
+    var file;
+    if (map["file"] != null) {
+      final fileMap = map["file"];
+      file = ConversationMessageFile(
+        url: fileMap["url"],
+        size: fileMap["size"],
+        name: fileMap["name"],
+        thumbnail: fileMap["thumbnail"],
+        type: fileMap["type"],
+      );
+    }
+
+    var serverMessage;
+    if (map["server_message"] != null) {
+      final srvMessageMap = map["server_message"];
+      serverMessage = ConversationServerMessage(
+        type: srvMessageMap["type"],
+        userID: srvMessageMap["user_id"],
+        userWhoAdded: srvMessageMap["user_who_added"],
+        userAdded: srvMessageMap["user_added"],
+        userWhoRemoved: srvMessageMap["user_who_removed"],
+        userRemoved: srvMessageMap["user_removed"],
+      );
+    }
+
     return ConversationMessage(
-      id: map["ID"],
+        id: map["id"],
-      conversationID: map["convID"],
+        convID: map["conv_id"],
-      userID: map["ID_user"],
+        userID: map["user_id"],
-      timeInsert: map["time_insert"],
+        timeSent: map["time_sent"],
-      message: DisplayedString(map["message"]),
+        message: DisplayedString(map["message"] ?? ""),
-      imageURL: map["image_path"],
+        file: file,
-    );
+        serverMessage: serverMessage);
   }
 }

lib/helpers/database/conversation_messages_database_helper.dart

@@ -1,37 +0,0 @@
-import 'package:comunic/helpers/database/database_contract.dart';
-import 'package:comunic/helpers/database/model_database_helper.dart';
-import 'package:comunic/lists/conversation_messages_list.dart';
-import 'package:comunic/models/conversation_message.dart';
-
-/// Conversation messages database helper
-///
-/// @author Pierre HUBERT
-
-class ConversationMessagesDatabaseHelper
-    extends ModelDatabaseHelper<ConversationMessage> {
-  @override
-  ConversationMessage initializeFromMap(Map<String, dynamic> map) {
-    return ConversationMessage.fromMap(map);
-  }
-
-  @override
-  String tableName() {
-    return ConversationsMessagesTableContract.TABLE_NAME;
-  }
-
-  /// Get all the message cached for a given conversation
-  Future<ConversationMessagesList> getAllMessagesConversations(
-      int conversationID,
-      {int lastMessageID = 0}) async {
-    final list = await getMultiple(
-      where: "${ConversationsMessagesTableContract.C_CONVERSATION_ID} = ? "
-          "AND ${BaseTableContract.C_ID} > ?",
-      whereArgs: [conversationID, lastMessageID],
-    );
-
-    // Turn the list into a conversation messages list
-    ConversationMessagesList finalList = ConversationMessagesList();
-    finalList.addAll(list);
-    return finalList;
-  }
-}

lib/helpers/database/conversations_database_helper.dart

@@ -1,29 +0,0 @@
-import 'package:comunic/helpers/database/database_contract.dart';
-import 'package:comunic/helpers/database/model_database_helper.dart';
-import 'package:comunic/lists/conversations_list.dart';
-import 'package:comunic/models/conversation.dart';
-
-/// Conversations database helper
-///
-/// @author Pierre HUBERT
-
-class ConversationsDatabaseHelper extends ModelDatabaseHelper<Conversation> {
-  @override
-  Conversation initializeFromMap(Map<String, dynamic> map) {
-    return Conversation.fromMap(map);
-  }
-
-  @override
-  String tableName() {
-    return ConversationTableContract.TABLE_NAME;
-  }
-
-  @override
-  Future<ConversationsList> getAll() async {
-    ConversationsList list = ConversationsList();
-    list.addAll(await super.getAll());
-    return list;
-  }
-
-
-}

lib/helpers/database/database_contract.dart

@@ -25,30 +25,6 @@ abstract class UserTableContract {
   static const C_CUSTOM_EMOJIES = "custom_emojies";
 }
 
-/// Conversations table contract
-abstract class ConversationTableContract {
-  static const TABLE_NAME = "conversations";
-  static const C_ID = BaseTableContract.C_ID;
-  static const C_OWNER_ID = "owner_id";
-  static const C_LAST_ACTIVE = "last_active";
-  static const C_NAME = "name";
-  static const C_FOLLOWING = "following";
-  static const C_SAW_LAST_MESSAGE = "saw_last_message";
-  static const C_MEMBERS = "members";
-  static const C_CAN_EVERYONE_ADD_MEMBERS = "can_everyone_add_members";
-}
-
-/// Conversations messages table contract
-abstract class ConversationsMessagesTableContract {
-  static const TABLE_NAME = "conversations_messages";
-  static const C_ID = BaseTableContract.C_ID;
-  static const C_CONVERSATION_ID = "conversation_id";
-  static const C_USER_ID = "user_id";
-  static const C_TIME_INSERT = "time_insert";
-  static const C_MESSAGE = "message";
-  static const C_IMAGE_URL = "image_url";
-}
-
 /// Friends table contract
 abstract class FriendsListTableContract {
   static const TABLE_NAME = "friends";

lib/helpers/database/database_helper.dart

@@ -45,14 +45,6 @@ abstract class DatabaseHelper {
     // Drop users table
     await db.execute("DROP TABLE IF EXISTS ${UserTableContract.TABLE_NAME}");
 
-    // Drop conversations table
-    await db.execute(
-        "DROP TABLE IF EXISTS ${ConversationTableContract.TABLE_NAME}");
-
-    // Drop conversations messages table
-    await db.execute(
-        "DROP TABLE IF EXISTS ${ConversationsMessagesTableContract.TABLE_NAME}");
-
     // Drop friends list table
     await db
         .execute("DROP TABLE IF EXISTS ${FriendsListTableContract.TABLE_NAME}");
@@ -74,29 +66,6 @@ abstract class DatabaseHelper {
         "${UserTableContract.C_CUSTOM_EMOJIES} TEXT"
         ")");
 
-    // Create conversations table
-    await db.execute("CREATE TABLE ${ConversationTableContract.TABLE_NAME} ("
-        "${ConversationTableContract.C_ID} INTEGER PRIMARY KEY, "
-        "${ConversationTableContract.C_OWNER_ID} INTEGER, "
-        "${ConversationTableContract.C_LAST_ACTIVE} INTEGER, "
-        "${ConversationTableContract.C_NAME} TEXT, "
-        "${ConversationTableContract.C_FOLLOWING} INTEGER, "
-        "${ConversationTableContract.C_SAW_LAST_MESSAGE} INTEGER, "
-        "${ConversationTableContract.C_MEMBERS} TEXT, "
-        "${ConversationTableContract.C_CAN_EVERYONE_ADD_MEMBERS} INTEGER"
-        ")");
-
-    // Create conversation messages table
-    await db.execute(
-        "CREATE TABLE ${ConversationsMessagesTableContract.TABLE_NAME} ("
-        "${ConversationsMessagesTableContract.C_ID} INTEGER PRIMARY KEY, "
-        "${ConversationsMessagesTableContract.C_CONVERSATION_ID} INTEGER, "
-        "${ConversationsMessagesTableContract.C_USER_ID} INTEGER, "
-        "${ConversationsMessagesTableContract.C_TIME_INSERT} INTEGER, "
-        "${ConversationsMessagesTableContract.C_MESSAGE} TEXT, "
-        "${ConversationsMessagesTableContract.C_IMAGE_URL} TEXT"
-        ")");
-
     // Friends list table
     await db.execute("CREATE TABLE ${FriendsListTableContract.TABLE_NAME} ("
         "${FriendsListTableContract.C_ID} INTEGER PRIMARY KEY, "

lib/helpers/serialization/base_serialization_helper.dart

@@ -0,0 +1,121 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:comunic/constants.dart';
+import 'package:path/path.dart' as path;
+import 'package:path_provider/path_provider.dart';
+
+/// Base serialization helper
+///
+/// @author Pierre Hubert
+
+abstract class SerializableElement<T> extends Comparable<T> {
+  Map<String, dynamic> toJson();
+}
+
+abstract class BaseSerializationHelper<T extends SerializableElement> {
+  /// List cache
+  List<T> _cache;
+
+  /// The name of the type of data to serialise
+  String get type;
+
+  /// Parse an json entry into a [T] object
+  T parse(Map<String, dynamic> m);
+
+  /// Get the file where data should be stored
+  Future<File> _getFilePath() async {
+    final dir = await getApplicationDocumentsDirectory();
+    final targetDir =
+        Directory(path.join(dir.absolute.path, SERIALIZATION_DIRECTORY));
+
+    targetDir.create(recursive: true);
+
+    return File(path.join(targetDir.absolute.path, type));
+  }
+
+  /// Load the cache
+  Future<void> _loadCache() async {
+    if (_cache != null) return;
+
+    try {
+      final file = await _getFilePath();
+
+      if (!await file.exists()) return _cache = List();
+
+      final List<dynamic> json = jsonDecode(await file.readAsString());
+      _cache = json.cast<Map<String, dynamic>>().map(parse).toList();
+
+      _cache.sort();
+    } catch (e, s) {
+      print("Failed to read serialized data! $e => $s");
+      _cache = List();
+    }
+  }
+
+  /// Save the cache to the persistent memory
+  Future<void> _saveCache() async {
+    final file = await _getFilePath();
+    await file.writeAsString(jsonEncode(
+        _cache.map((e) => e.toJson()).toList().cast<Map<String, dynamic>>()));
+  }
+
+  /// Get the current list of elements
+  Future<List<T>> getList() async {
+    await _loadCache();
+    return List.from(_cache);
+  }
+
+  /// Set a new list of conversations
+  Future<void> setList(List<T> list) async {
+    _cache = List.from(list);
+    await _saveCache();
+  }
+
+  /// Insert new element
+  Future<void> insert(T el) async {
+    await _loadCache();
+    _cache.add(el);
+    _cache.sort();
+    await _saveCache();
+  }
+
+  /// Insert new element
+  Future<void> insertMany(List<T> els) async {
+    await _loadCache();
+    _cache.addAll(els);
+    _cache.sort();
+    await _saveCache();
+  }
+
+  /// Check if any entry in the last match the predicate
+  Future<bool> any(bool isContained(T t)) async {
+    await _loadCache();
+    return _cache.any((element) => isContained(element));
+  }
+
+  /// Check if any entry in the last match the predicate
+  Future<T> first(bool filter(T t)) async {
+    await _loadCache();
+    return _cache.firstWhere((element) => filter(element));
+  }
+
+  /// Replace an element with another one
+  Future<void> insertOrReplaceElement(bool isToReplace(T t), T newEl) async {
+    await _loadCache();
+
+    // Insert or replace the element
+    _cache.where((element) => !isToReplace(element)).toList();
+    _cache.add(newEl);
+
+    _cache.sort();
+    await _saveCache();
+  }
+
+  /// Remove elements
+  Future<void> removeElement(bool isToRemove(T t)) async {
+    await _loadCache();
+    _cache.removeWhere((element) => isToRemove(element));
+    await _saveCache();
+  }
+}

lib/helpers/serialization/conversation_message_serialization_helper.dart

@@ -0,0 +1,50 @@
+import 'dart:collection';
+
+import 'package:comunic/helpers/serialization/base_serialization_helper.dart';
+import 'package:comunic/lists/conversation_messages_list.dart';
+import 'package:comunic/models/conversation_message.dart';
+
+/// Conversations serialization helper
+///
+/// @author Pierre Hubert
+
+final HashMap<int, ConversationsMessagesSerializationHelper> _instances =
+    HashSet() as HashMap<int, ConversationsMessagesSerializationHelper>;
+
+class ConversationsMessagesSerializationHelper
+    extends BaseSerializationHelper<ConversationMessage> {
+  final int convID;
+
+  ConversationsMessagesSerializationHelper._(int convID)
+      : convID = convID,
+        assert(convID != null);
+
+  factory ConversationsMessagesSerializationHelper(int convID) {
+    if (!_instances.containsKey(convID))
+      _instances[convID] = ConversationsMessagesSerializationHelper._(convID);
+
+    return _instances[convID];
+  }
+
+  @override
+  ConversationMessage parse(Map<String, dynamic> m) =>
+      ConversationMessage.fromJson(m);
+
+  @override
+  String get type => "conv-messages-$convID";
+
+  Future<ConversationMessagesList> getList() async =>
+      ConversationMessagesList()..addAll(await super.getList());
+
+  Future<void> insertOrReplace(ConversationMessage msg) async =>
+      await insertOrReplaceElement((t) => t.id == msg.id, msg);
+
+  Future<void> remove(ConversationMessage msg) async =>
+      await removeElement((t) => t.id == msg.id);
+
+  /// Insert or replace a list of messages
+  Future<void> insertOrReplaceAll(List<ConversationMessage> list) async {
+    for (var message in list)
+      await insertOrReplaceElement((t) => t.id == message.id, message);
+  }
+}

lib/helpers/serialization/conversations_serialization_helper.dart

@@ -0,0 +1,32 @@
+import 'package:comunic/helpers/serialization/base_serialization_helper.dart';
+import 'package:comunic/lists/conversations_list.dart';
+import 'package:comunic/models/conversation.dart';
+
+/// Conversations serialization helper
+///
+/// @author Pierre Hubert
+
+var _cache;
+
+class ConversationsSerializationHelper
+    extends BaseSerializationHelper<Conversation> {
+  /// Singleton
+  factory ConversationsSerializationHelper() {
+    if (_cache == null) _cache = ConversationsSerializationHelper._();
+    return _cache;
+  }
+
+  ConversationsSerializationHelper._();
+
+  @override
+  Conversation parse(Map<String, dynamic> m) => Conversation.fromJson(m);
+
+  @override
+  String get type => "conversations";
+
+  Future<ConversationsList> getList() async =>
+      ConversationsList()..addAll(await super.getList());
+
+  /// Get a conversation
+  Future<Conversation> get(int id) => first((t) => t.id == id);
+}

lib/helpers/users_helper.dart

@@ -91,9 +91,16 @@ class UsersHelper {
   }
 
   /// Get users information from a given [Set]
+  ///
+  /// Throws in case of failure
   Future<UsersList> getList(Set<int> users,
       {bool forceDownload = false}) async {
-    return await getUsersInfo(users.toList());
+    final list = await getUsersInfo(users.toList());
+
+    if (list == null)
+      throw Exception("Failed to get the list of users!");
+
+    return list;
   }
 
   /// Get users information

lib/lists/conversations_list.dart

@@ -8,11 +8,11 @@ import 'package:comunic/models/conversation.dart';
 /// @author Pierre HUBERT
 
 class ConversationsList extends ListBase<Conversation> {
-
   final List<Conversation> _list = List();
   UsersList users;
 
   set length(l) => _list.length = l;
+
   int get length => _list.length;
 
   @override
@@ -22,12 +22,9 @@ class ConversationsList extends ListBase<Conversation> {
   void operator []=(int index, Conversation value) => _list[index] = value;
 
   /// Get the entire lists of users ID in this list
-  List<int> get allUsersID {
+  Set<int> get allUsersID {
-    final List<int> list = List();
+    final Set<int> list = Set();
-    forEach((c) => c.members.forEach((id){
+    forEach((c) => c.members.forEach((member) => list.add(member.userID)));
-      if(!list.contains(id))
-        list.add(id);
-    }));
     return list;
   }
 }

lib/lists/memberships_list.dart

@@ -18,7 +18,7 @@ class MembershipList extends AbstractList<Membership> {
         case MembershipType.GROUP:
           break;
         case MembershipType.CONVERSATION:
-          s.addAll(m.conversation.members);
+          s.addAll(m.conversation.membersID);
           break;
       }
     });

lib/lists/unread_conversations_list.dart

@@ -7,5 +7,9 @@ import 'package:comunic/models/unread_conversation.dart';
 
 class UnreadConversationsList extends AbstractList<UnreadConversation> {
   /// Get the ID of the users included in this list
-  Set<int> get usersID => new Set<int>()..addAll(map((f) => f.userID));
+  Set<int> get usersID {
+    final set = Set();
+    forEach((element) => set.addAll(element.message.usersID));
+    return set;
+  }
 }

lib/models/conversation.dart

@@ -1,7 +1,6 @@
-import 'package:comunic/helpers/database/database_contract.dart';
+import 'package:comunic/helpers/serialization/base_serialization_helper.dart';
-import 'package:comunic/models/cache_model.dart';
+import 'package:comunic/models/conversation_member.dart';
 import 'package:comunic/utils/account_utils.dart';
-import 'package:comunic/utils/list_utils.dart';
 import 'package:meta/meta.dart';
 
 /// Conversation model
@@ -10,79 +9,86 @@ import 'package:meta/meta.dart';
 
 enum CallCapabilities { NONE, AUDIO, VIDEO }
 
-class Conversation extends CacheModel implements Comparable {
+class Conversation extends SerializableElement<Conversation> {
-  final int ownerID;
+  final int id;
-  final int lastActive;
+  final int lastActivity;
   final String name;
-  final bool following;
+  final String color;
-  final bool sawLastMessage;
+  final String logoURL;
-  final List<int> members;
+  final int groupID;
+  final List<ConversationMember> members;
   final bool canEveryoneAddMembers;
   final CallCapabilities callCapabilities;
   final bool isHavingCall;
 
-  const Conversation({
+  Conversation({
-    @required int id,
+    @required this.id,
-    @required this.ownerID,
+    @required this.lastActivity,
-    @required this.lastActive,
     @required this.name,
-    @required this.following,
+    @required this.color,
-    @required this.sawLastMessage,
+    @required this.logoURL,
+    @required this.groupID,
     @required this.members,
     @required this.canEveryoneAddMembers,
     this.callCapabilities = CallCapabilities.NONE,
     this.isHavingCall = false,
   })  : assert(id != null),
-        assert(ownerID != null),
+        assert(lastActivity != null),
-        assert(lastActive != null),
-        assert(following != null),
-        assert(sawLastMessage != null),
         assert(members != null),
         assert(canEveryoneAddMembers != null),
         assert(callCapabilities != null),
-        assert(isHavingCall != null),
+        assert(isHavingCall != null);
-        super(id: id);
 
   /// Check out whether a conversation has a fixed name or not
   bool get hasName => this.name != null;
 
-  /// Check out whether current user of the application is the owner of it or
+  /// Get current user membership
-  /// not
+  ConversationMember get membership =>
-  bool get isOwner => this.ownerID == userID();
+      members.firstWhere((m) => m.userID == userID());
 
-  Conversation.fromMap(Map<String, dynamic> map)
+  /// Check out whether current user of the application is an admin
-      : ownerID = map[ConversationTableContract.C_OWNER_ID],
+  bool get isAdmin => membership.isAdmin;
-        lastActive = map[ConversationTableContract.C_LAST_ACTIVE],
+
-        name = map[ConversationTableContract.C_NAME],
+  /// Check it current user is following the conversation or not
-        following = map[ConversationTableContract.C_FOLLOWING] == 1,
+  bool get following => membership.following;
-        sawLastMessage = map[ConversationTableContract.C_SAW_LAST_MESSAGE] == 1,
+
-        members =
+  /// Get the list of members in the conversation
-            listToIntList(map[ConversationTableContract.C_MEMBERS].split(",")),
+  Set<int> get membersID => members.map((e) => e.userID).toSet();
-        canEveryoneAddMembers =
+
-            map[ConversationTableContract.C_CAN_EVERYONE_ADD_MEMBERS] == 1,
+  /// Check if the last message has been seen or not
+  bool get sawLastMessage => lastActivity <= membership.lastAccessTime;
+
+  Conversation.fromJson(Map<String, dynamic> map)
+      : id = map["id"],
+        name = map["name"],
+        color = map["color"],
+        logoURL = map["logoURL"],
+        groupID = map["groupID"],
+        lastActivity = map["lastActivity"],
+        members = map["members"]
+            .map((el) => ConversationMember.fromJSON(el))
+            .toList(),
+        canEveryoneAddMembers = map["canEveryoneAddMembers"],
 
         // By default, we can not do any call
         callCapabilities = CallCapabilities.NONE,
-        isHavingCall = false,
+        isHavingCall = false;
-        super.fromMap(map);
 
-  @override
+  Map<String, dynamic> toJson() {
-  Map<String, dynamic> toMap() {
     return {
-      ConversationTableContract.C_ID: id,
+      "id": id,
-      ConversationTableContract.C_OWNER_ID: ownerID,
+      "name": name,
-      ConversationTableContract.C_LAST_ACTIVE: lastActive,
+      "color": color,
-      ConversationTableContract.C_NAME: name,
+      "logoURL": logoURL,
-      ConversationTableContract.C_FOLLOWING: following ? 1 : 0,
+      "groupID": groupID,
-      ConversationTableContract.C_SAW_LAST_MESSAGE: sawLastMessage ? 1 : 0,
+      "lastActivity": lastActivity,
-      ConversationTableContract.C_MEMBERS: members.join(","),
+      "members": members.map((e) => e.toJson()).toList(),
-      ConversationTableContract.C_CAN_EVERYONE_ADD_MEMBERS:
+      "canEveryoneAddMembers": canEveryoneAddMembers,
-          canEveryoneAddMembers ? 1 : 0
     };
   }
 
   @override
-  int compareTo(other) {
+  int compareTo(Conversation other) {
-    return other.lastActive.compareTo(this.lastActive);
+    return other.lastActivity.compareTo(this.lastActivity);
   }
 }

lib/models/conversation_member.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/widgets.dart';
+
+/// Conversation member
+///
+/// @author Pierre Hubert
+
+class ConversationMember {
+  final int userID;
+  final int lastMessageSeen;
+  final int lastAccessTime;
+  final bool following;
+  final bool isAdmin;
+
+  const ConversationMember({
+    @required this.userID,
+    @required this.lastMessageSeen,
+    @required this.lastAccessTime,
+    @required this.following,
+    @required this.isAdmin,
+  })  : assert(userID != null),
+        assert(lastMessageSeen != null),
+        assert(lastAccessTime != null),
+        assert(following != null),
+        assert(isAdmin != null);
+
+  Map<String, dynamic> toJson() => {
+        'userID': userID,
+        'lastMessageSeen': lastMessageSeen,
+        'lastAccessTime': lastAccessTime,
+        'following': following,
+        'isAdmin': isAdmin,
+      };
+
+  ConversationMember.fromJSON(Map<String, dynamic> json)
+      : userID = json["userID"],
+        lastMessageSeen = json["lastMessageSeen"],
+        lastAccessTime = json["lastAccessTime"],
+        following = json["following"],
+        isAdmin = json["isAdmin"];
+}

lib/models/conversation_message.dart

@@ -1,5 +1,4 @@
-import 'package:comunic/helpers/database/database_contract.dart';
+import 'package:comunic/helpers/serialization/base_serialization_helper.dart';
-import 'package:comunic/models/cache_model.dart';
 import 'package:comunic/models/displayed_content.dart';
 import 'package:comunic/utils/account_utils.dart' as account;
 import 'package:meta/meta.dart';
@@ -8,59 +7,171 @@ import 'package:meta/meta.dart';
 ///
 /// @author Pierre HUBERT
 
-class ConversationMessage extends CacheModel implements Comparable {
+class ConversationMessageFile {
-  final int id;
+  final String url;
-  final int conversationID;
+  final int size;
+  final String name;
+  final String thumbnail;
+  final String type;
+
+  const ConversationMessageFile({
+    @required this.url,
+    @required this.size,
+    @required this.name,
+    @required this.thumbnail,
+    @required this.type,
+  })  : assert(url != null),
+        assert(size != null),
+        assert(name != null),
+        assert(type != null);
+
+  Map<String, dynamic> toJson() => {
+        "url": url,
+        "size": size,
+        "name": name,
+        "thumbnail": thumbnail,
+        "type": type
+      };
+
+  ConversationMessageFile.fromJson(Map<String, dynamic> json)
+      : url = json["url"],
+        size = json["size"],
+        name = json["name"],
+        thumbnail = json["thumbnail"],
+        type = json["type"];
+}
+
+enum ConversationServerMessageType {
+  USER_CREATED_CONVERSATION,
+  USER_ADDED_ANOTHER_USER,
+  USER_LEFT_CONV,
+  USER_REMOVED_ANOTHER_USER
+}
+
+class ConversationServerMessage {
+  final ConversationServerMessageType type;
   final int userID;
-  final int timeInsert;
+  final int userWhoAdded;
-  final DisplayedString message;
+  final int userAdded;
-  final String imageURL;
+  final int userWhoRemoved;
+  final int userRemoved;
 
-  const ConversationMessage({
+  const ConversationServerMessage({
-    @required this.id,
+    @required this.type,
-    @required this.conversationID,
     @required this.userID,
-    @required this.timeInsert,
+    @required this.userWhoAdded,
-    @required this.message,
+    @required this.userAdded,
-    @required this.imageURL,
+    @required this.userWhoRemoved,
-  })  : assert(id != null),
+    @required this.userRemoved,
-        assert(userID != null),
+  })  : assert(type != null),
-        assert(timeInsert != null),
+        assert(userID != null ||
-        assert(message != null),
+            (type != ConversationServerMessageType.USER_CREATED_CONVERSATION &&
-        super(id: id);
+                type != ConversationServerMessageType.USER_LEFT_CONV)),
+        assert((userWhoAdded != null && userAdded != null) ||
+            type != ConversationServerMessageType.USER_ADDED_ANOTHER_USER),
+        assert((userWhoRemoved != null && userRemoved != null) ||
+            type != ConversationServerMessageType.USER_REMOVED_ANOTHER_USER);
 
-  DateTime get date => DateTime.fromMillisecondsSinceEpoch(timeInsert * 1000);
+  Set<int> get usersID {
+    switch (type) {
+      case ConversationServerMessageType.USER_CREATED_CONVERSATION:
+      case ConversationServerMessageType.USER_LEFT_CONV:
+        return Set()..add(userID);
+
+      case ConversationServerMessageType.USER_ADDED_ANOTHER_USER:
+        return Set()..add(userWhoAdded)..add(userAdded);
+
+      case ConversationServerMessageType.USER_REMOVED_ANOTHER_USER:
+        return Set()..add(userWhoRemoved)..add(userRemoved);
+    }
+
+    throw Exception("Unsupported server message type!");
+  }
+
+  Map<String, dynamic> toJson() => {
+        "type": type.toString(),
+        "userID": userID,
+        "userWhoAdded": userWhoAdded,
+        "userAdded": userAdded,
+        "userWhoRemoved": userWhoRemoved,
+        "userRemoved": userRemoved,
+      };
+
+  ConversationServerMessage.fromJson(Map<String, dynamic> json)
+      : type = ConversationServerMessageType.values
+            .firstWhere((el) => el.toString() == json["type"]),
+        userID = json["userID"],
+        userWhoAdded = json["userWhoAdded"],
+        userAdded = json["userAdded"],
+        userWhoRemoved = json["userWhoRemoved"],
+        userRemoved = json["userRemoved"];
+}
+
+class ConversationMessage extends SerializableElement<ConversationMessage> {
+  final int id;
+  final int convID;
+  final int userID;
+  final int timeSent;
+  final DisplayedString message;
+  final ConversationMessageFile file;
+  final ConversationServerMessage serverMessage;
+
+  ConversationMessage({
+    @required this.id,
+    @required this.convID,
+    @required this.userID,
+    @required this.timeSent,
+    @required this.message,
+    @required this.file,
+    @required this.serverMessage,
+  })  : assert(id != null),
+        assert(convID != null),
+        assert(userID != null),
+        assert(timeSent != null),
+        assert(message != null || file != null || serverMessage != null);
+
+  DateTime get date => DateTime.fromMillisecondsSinceEpoch(timeSent * 1000);
 
   bool get hasMessage => !message.isNull && message.length > 0;
 
-  bool get hasImage => imageURL != null && imageURL != "null";
+  bool get hasFile => file != null;
+
+  bool get hasThumbnail => hasFile && file.thumbnail != null;
+
+  bool get hasImage => hasFile && file.type.startsWith("image/");
 
   bool get isOwner => account.userID() == userID;
 
+  /// Get the list of the ID of the users implied in this message
+  Set<int> get usersID {
+    if (userID != null) return Set()..add(userID);
+
+    return serverMessage.usersID;
+  }
+
   @override
-  int compareTo(other) {
+  int compareTo(ConversationMessage other) {
     return id.compareTo(other.id);
   }
 
-  @override
+  Map<String, dynamic> toJson() {
-  Map<String, dynamic> toMap() {
     return {
-      ConversationsMessagesTableContract.C_ID: id,
+      "id": id,
-      ConversationsMessagesTableContract.C_CONVERSATION_ID: conversationID,
+      "convID": convID,
-      ConversationsMessagesTableContract.C_USER_ID: userID,
+      "userID": userID,
-      ConversationsMessagesTableContract.C_TIME_INSERT: timeInsert,
+      "timeSent": timeSent,
-      ConversationsMessagesTableContract.C_MESSAGE: message.content,
+      "message": message,
-      ConversationsMessagesTableContract.C_IMAGE_URL: imageURL
+      "file": file?.toJson(),
+      "serverMessage": serverMessage?.toJson(),
     };
   }
 
-  ConversationMessage.fromMap(Map<String, dynamic> map)
+  ConversationMessage.fromJson(Map<String, dynamic> map)
-      : id = map[ConversationsMessagesTableContract.C_ID],
+      : id = map["id"],
-        conversationID =
+        convID = map["convID"],
-            map[ConversationsMessagesTableContract.C_CONVERSATION_ID],
+        userID = map["userID"],
-        userID = map[ConversationsMessagesTableContract.C_USER_ID],
+        timeSent = map["timeSent"],
-        timeInsert = map[ConversationsMessagesTableContract.C_TIME_INSERT],
+        message = DisplayedString(map["message"]),
-        message = DisplayedString(map[ConversationsMessagesTableContract.C_MESSAGE]),
+        file = map["file"],
-        imageURL = map[ConversationsMessagesTableContract.C_IMAGE_URL],
+        serverMessage = map["serverMessage"];
-        super.fromMap(map);
 }

lib/models/membership.dart

@@ -43,7 +43,7 @@ class Membership {
       case MembershipType.GROUP:
         return groupLastActive;
       case MembershipType.CONVERSATION:
-        return conversation.lastActive;
+        return conversation.lastActivity;
       default:
         throw Exception("Unreachable statment!");
     }

lib/models/new_conversation.dart

@@ -0,0 +1,24 @@
+import 'package:flutter/cupertino.dart';
+
+/// New conversation information
+///
+/// @author Pierre Hubert
+
+class NewConversation {
+  final String name;
+  final List<int> members;
+  final bool follow;
+  final bool canEveryoneAddMembers;
+  final String color;
+
+  const NewConversation({
+    @required this.name,
+    @required this.members,
+    @required this.follow,
+    @required this.canEveryoneAddMembers,
+    @required this.color,
+  })  : assert(members != null),
+        assert(members.length > 0),
+        assert(follow != null),
+        assert(canEveryoneAddMembers != null);
+}

lib/models/new_conversation_settings.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/widgets.dart';
+
+/// Conversation settings update
+///
+/// @author Pierre Hubert
+
+class NewConversationsSettings {
+  final int convID;
+  final bool following;
+  final bool isComplete;
+  final String name;
+  final bool canEveryoneAddMembers;
+  final String color;
+
+  const NewConversationsSettings({
+    @required this.convID,
+    @required this.following,
+    @required this.isComplete,
+    @required this.name,
+    @required this.canEveryoneAddMembers,
+    @required this.color,
+  })  : assert(convID != null),
+        assert(convID > 0),
+        assert(following != null),
+        assert(isComplete != null),
+        assert(!isComplete && canEveryoneAddMembers != null);
+}

lib/models/unread_conversation.dart

@@ -1,3 +1,5 @@
+import 'package:comunic/models/conversation.dart';
+import 'package:comunic/models/conversation_message.dart';
 import 'package:flutter/material.dart';
 
 /// Unread conversation information
@@ -5,21 +7,12 @@ import 'package:flutter/material.dart';
 /// @author Pierre Hubert
 
 class UnreadConversation {
-  final int id;
+  final Conversation conv;
-  final String convName;
+  final ConversationMessage message;
-  final int lastActive;
-  final int userID;
-  final String message;
 
   const UnreadConversation({
-    @required this.id,
+    @required this.conv,
-    @required this.convName,
-    @required this.lastActive,
-    @required this.userID,
     @required this.message,
-  })  : assert(id != null),
+  })  : assert(conv != null),
-        assert(convName != null),
-        assert(lastActive != null),
-        assert(userID != null),
         assert(message != null);
 }

lib/ui/routes/conversation_route.dart

@@ -4,6 +4,7 @@ import 'package:comunic/ui/routes/main_route/main_route.dart';
 import 'package:comunic/ui/routes/update_conversation_route.dart';
 import 'package:comunic/ui/screens/conversation_screen.dart';
 import 'package:comunic/ui/widgets/comunic_back_button_widget.dart';
+import 'package:comunic/ui/widgets/safe_state.dart';
 import 'package:comunic/utils/intl_utils.dart';
 import 'package:comunic/utils/ui_utils.dart';
 import 'package:flutter/material.dart';
@@ -25,7 +26,7 @@ class ConversationRoute extends StatefulWidget {
   State<StatefulWidget> createState() => _ConversationRouteState();
 }
 
-class _ConversationRouteState extends State<ConversationRoute> {
+class _ConversationRouteState extends SafeState<ConversationRoute> {
   final ConversationsHelper _conversationsHelper = ConversationsHelper();
   Conversation _conversation;
   String _conversationName;
@@ -42,21 +43,22 @@ class _ConversationRouteState extends State<ConversationRoute> {
   Future<void> _loadConversation() async {
     setError(false);
 
-    _conversation = await _conversationsHelper.getSingle(widget.conversationID,
+    try {
-        force: true);
+      _conversation = await _conversationsHelper
+          .getSingle(widget.conversationID, force: true);
 
-    if (_conversation == null) return setError(true);
+      if (_conversation == null) return setError(true);
 
-    final conversationName =
+      final conversationName =
-        await ConversationsHelper.getConversationNameAsync(_conversation);
+          await ConversationsHelper.getConversationNameAsync(_conversation);
 
-    if (!this.mounted) return null;
+      if (!this.mounted) return null;
 
-    if (conversationName == null) return setError(true);
+      setState(() => _conversationName = conversationName);
-
+    } catch (e, s) {
-    setState(() {
+      print("Failed to get conversation name! $e => $s");
-      _conversationName = conversationName;
+      setError(true);
-    });
+    }
   }
 
   void _openSettings() {

lib/ui/routes/update_conversation_route.dart

@@ -42,19 +42,18 @@ class _UpdateConversationRoute extends State<UpdateConversationRoute> {
   Future<void> _loadConversation() async {
     setError(false);
 
-    final conversation = await ConversationsHelper()
+    try {
-        .getSingle(widget.conversationID, force: true);
+      final conversation = await ConversationsHelper()
+          .getSingle(widget.conversationID, force: true);
 
-    if (conversation == null) return setError(true);
+      //Load information about the members of the conversation
+      _membersInfo = await UsersHelper().getList(conversation.membersID);
 
-    //Load information about the members of the conversation
+      setState(() => _conversation = conversation);
-    _membersInfo = await UsersHelper().getUsersInfo(conversation.members);
+    } catch (e, s) {
-
+      print("Failed to load conversation information! $e=>$s");
-    if (_membersInfo == null) return setError(true);
+      setError(true);
-
+    }
-    setState(() {
-      _conversation = conversation;
-    });
   }
 
   /// Build the body of this widget

lib/ui/screens/call_screen.dart

@@ -110,7 +110,7 @@ class _CallScreenState extends SafeState<CallScreen> {
 
       // First, load information about the conversation
       _conversation =
-          await ConversationsHelper().getSingleOrThrow(convID, force: true);
+          await ConversationsHelper().getSingle(convID, force: true);
       _convName =
           await ConversationsHelper.getConversationNameAsync(_conversation);
       assert(_convName != null);

lib/ui/screens/conversation_members_screen.dart

@@ -32,8 +32,7 @@ class _ConversationMembersScreenState extends State<ConversationMembersScreen> {
   Future<void> _refresh() async {
     _conversation =
         await ConversationsHelper().getSingle(widget.convID, force: true);
-    _members =
+    _members = await UsersHelper().getListWithThrow(_conversation.membersID);
-        await UsersHelper().getListWithThrow(_conversation.members.toSet());
   }
 
   @override
@@ -55,12 +54,12 @@ class _ConversationMembersScreenState extends State<ConversationMembersScreen> {
       );
 
   Widget _buildItem(BuildContext context, int index) {
-    final user = _members.getUser(_conversation.members[index]);
+    final member = _conversation.members[index];
+    final user = _members.getUser(member.userID);
     return ListTile(
       leading: AccountImageWidget(user: user),
       title: Text(user.displayName),
-      subtitle:
+      subtitle: Text(member.isAdmin ? tr("Admin") : tr("Member")),
-          Text(_conversation.ownerID == user.id ? tr("Owner") : tr("Member")),
     );
   }
 }

lib/ui/screens/conversation_screen.dart

@@ -70,9 +70,8 @@ class _ConversationScreenState extends SafeState<ConversationScreen> {
       });
 
   /// Method called when an error occurred while loading messages
-  void _errorLoading() {
+  void _errorLoading() =>
-    _setError(_messages == null ? ErrorLevel.MAJOR : ErrorLevel.MINOR);
+      _setError(_messages == null ? ErrorLevel.MAJOR : ErrorLevel.MINOR);
-  }
 
   /// Load the first conversations
   Future<void> _init() async {
@@ -86,22 +85,27 @@ class _ConversationScreenState extends SafeState<ConversationScreen> {
         .registerConversationEvents(widget.conversationID);
 
     this.listen<NewConversationMessageEvent>((ev) async {
-      if (ev.msg.conversationID == widget.conversationID) {
+      if (ev.msg.convID == widget.conversationID) {
-        await _conversationsHelper.saveMessage(ev.msg);
+        try {
-        await _applyNewMessages(ConversationMessagesList()..add(ev.msg));
+          await _conversationsHelper.saveMessage(ev.msg);
+          await _applyNewMessages(ConversationMessagesList()..add(ev.msg));
+        } catch (e, s) {
+          print("Failed to show new message! $e => $s");
+          _errorLoading();
+        }
       }
     });
 
     this.listen<UpdatedConversationMessageEvent>((ev) async {
-      if (ev.msg.conversationID == widget.conversationID) {
+      if (ev.msg.convID == widget.conversationID) {
         await _conversationsHelper.saveMessage(ev.msg);
         setState(() => _messages.replace(ev.msg));
       }
     });
 
     this.listen<DeletedConversationMessageEvent>((ev) async {
-      if (ev.msg.conversationID == widget.conversationID) {
+      if (ev.msg.convID == widget.conversationID) {
-        await _conversationsHelper.removeMessage(ev.msg.id);
+        await _conversationsHelper.removeMessage(ev.msg);
         setState(() => _messages.removeMsg(ev.msg.id));
       }
     });
@@ -116,19 +120,23 @@ class _ConversationScreenState extends SafeState<ConversationScreen> {
   Future<void> _loadMessages(bool online) async {
     if (!mounted) return;
 
-    //First, get the messages
+    try {
-    final messages = await _conversationsHelper.getNewMessages(
+      //First, get the messages
+      final messages = await _conversationsHelper.getNewMessages(
         conversationID: widget.conversationID,
         lastMessageID: _messages == null ? 0 : _messages.lastMessageID,
-        online: online);
+        online: online,
+      );
 
-    if (messages == null) return _errorLoading();
+      // In case we are offline and we did not get any message we do not do
+      // anything (we wait for the online request)
+      if (messages.length == 0 && !online) return;
 
-    // In case we are offline and we did not get any message we do not do
+      await _applyNewMessages(messages);
-    // anything (we wait for the online request)
+    } catch (e, s) {
-    if (messages.length == 0 && !online) return;
+      print("Failed to load messages! $e => $s");
-
+      _errorLoading();
-    await _applyNewMessages(messages);
+    }
   }
 
   /// Get older messages
@@ -136,45 +144,43 @@ class _ConversationScreenState extends SafeState<ConversationScreen> {
     if (_loadingOlderMessages != _OlderMessagesLevel.NONE ||
         _messages == null ||
         _messages.length == 0) return;
+    try {
+      // Let's start to load older messages
+      _setLoadingOlderMessagesState(_OlderMessagesLevel.LOADING);
 
-    // Let's start to load older messages
+      final messages = await _conversationsHelper.getOlderMessages(
-    _setLoadingOlderMessagesState(_OlderMessagesLevel.LOADING);
+          conversationID: widget.conversationID,
+          oldestMessagesID: _messages.firstMessageID);
 
-    final messages = await _conversationsHelper.getOlderMessages(
+      // Mark as not loading anymore
-        conversationID: widget.conversationID,
+      _setLoadingOlderMessagesState(_OlderMessagesLevel.NONE);
-        oldestMessagesID: _messages.firstMessageID);
 
-    // Mark as not loading anymore
+      // Check if there is no more unread messages
-    _setLoadingOlderMessagesState(_OlderMessagesLevel.NONE);
+      if (messages.length == 0) {
+        _setLoadingOlderMessagesState(_OlderMessagesLevel.NO_MORE_AVAILABLE);
+        return;
+      }
 
-    // Check for errors
+      // Apply the messages
-    if (messages == null) {
+      _applyNewMessages(messages);
+    } catch (e, s) {
+      print("Failed to load older messages! $e => $s");
       _errorLoading();
-      return;
     }
-
-    // Check if there is no more unread messages
-    if (messages.length == 0) {
-      _setLoadingOlderMessagesState(_OlderMessagesLevel.NO_MORE_AVAILABLE);
-      return;
-    }
-
-    // Apply the messages
-    _applyNewMessages(messages);
   }
 
   /// Apply new messages [messages] must not be null
+  ///
+  /// Throws in case of failure
   Future<void> _applyNewMessages(ConversationMessagesList messages) async {
     // We ignore new messages once the area is no longer visible
     if (!this.mounted) return;
 
     //Then get information about users
     final usersToGet =
-        findMissingFromList(_usersInfo.usersID, messages.getUsersID());
+        findMissingFromList(_usersInfo.usersID, messages.getUsersID()).toSet();
 
-    final users = await _usersHelper.getUsersInfo(usersToGet);
+    final users = await _usersHelper.getList(usersToGet);
-
-    if (users == null) _errorLoading();
 
     // Save the new list of messages
     setState(() {

lib/ui/screens/conversations_list_screen.dart

@@ -62,32 +62,24 @@ class _ConversationScreenState extends SafeState<ConversationsListScreen> {
     await _loadConversationsList(false);
   }
 
-  void _gotLoadingError() {
-    setError(_list == null ? LoadErrorLevel.MAJOR : LoadErrorLevel.MINOR);
-  }
-
   /// Load the list of conversations
   Future<void> _loadConversationsList(bool cached) async {
     setError(LoadErrorLevel.NONE);
 
-    //Get the list of conversations
+    try {
-    var list;
+      ConversationsList list = cached
-    if (cached)
+          ? await _conversationsHelper.getCachedList()
-      list = await _conversationsHelper.getCachedList();
+          : await _conversationsHelper.downloadList();
-    else
+      assert(list != null);
-      list = await _conversationsHelper.downloadList();
 
-    if (list == null) return _gotLoadingError();
+      //Get information about the members of the conversations
+      list.users = await _usersHelper.getList(list.allUsersID);
 
-    //Get information about the members of the conversations
+      setState(() => _list = list);
-    list.users = await _usersHelper.getUsersInfo(list.allUsersID);
+    } catch (e, s) {
-
+      debugPrint("Failed to get conversations list! $e => $s", wrapWidth: 1024);
-    if (list.users == null) return _gotLoadingError();
+      setError(_list == null ? LoadErrorLevel.MAJOR : LoadErrorLevel.MINOR);
-
+    }
-    //Save list
-    setState(() {
-      _list = list;
-    });
   }
 
   /// Build an error card
@@ -159,9 +151,13 @@ class _ConversationScreenState extends SafeState<ConversationsListScreen> {
     if (result == null || !result) return;
 
     // Request the conversation to be deleted now
-    if (!await _conversationsHelper.deleteConversation(conversation.id))
+    try {
+      await _conversationsHelper.deleteConversation(conversation.id);
+    } catch (e, s) {
+      print("Failed to delete conversation! $e => $s");
       Scaffold.of(context).showSnackBar(
           SnackBar(content: Text(tr("Could not delete the conversation!"))));
+    }
 
     // Reload the list of conversations
     _loadConversationsList(false);

lib/ui/screens/unread_conversations_screen.dart

@@ -3,11 +3,8 @@ import 'package:comunic/helpers/events_helper.dart';
 import 'package:comunic/helpers/users_helper.dart';
 import 'package:comunic/lists/unread_conversations_list.dart';
 import 'package:comunic/lists/users_list.dart';
-import 'package:comunic/ui/routes/main_route/main_route.dart';
-import 'package:comunic/ui/widgets/account_image_widget.dart';
 import 'package:comunic/ui/widgets/async_screen_widget.dart';
 import 'package:comunic/ui/widgets/safe_state.dart';
-import 'package:comunic/utils/date_utils.dart';
 import 'package:comunic/utils/intl_utils.dart';
 import 'package:flutter/material.dart';
 
@@ -70,7 +67,7 @@ class _UnreadConversationsScreenState
   }
 
   Widget _tileBuilder(BuildContext context, int index) {
-    final conv = _list[index];
+    /*final conv = _list[index];
     final user = _users.getUser(conv.userID);
     return ListTile(
       leading: AccountImageWidget(user: user),
@@ -83,9 +80,12 @@ class _UnreadConversationsScreenState
             style: TextStyle(fontStyle: FontStyle.italic),
           ),
         ]),
-      ),
+      )
       trailing: Text(diffTimeFromNowToStr(conv.lastActive)),
       onTap: () => MainController.of(context).openConversation(conv.id),
-    );
+    );*/
+
+    // TODO : reimplement
+    throw new Exception("unimplemented");
   }
 }

lib/ui/screens/update_conversation_screen.dart

@@ -1,8 +1,6 @@
-import 'package:comunic/helpers/conversations_helper.dart';
 import 'package:comunic/lists/users_list.dart';
 import 'package:comunic/models/conversation.dart';
 import 'package:comunic/models/user.dart';
-import 'package:comunic/ui/routes/main_route/main_route.dart';
 import 'package:comunic/ui/tiles/simple_user_tile.dart';
 import 'package:comunic/ui/widgets/pick_user_widget.dart';
 import 'package:comunic/utils/intl_utils.dart';
@@ -36,11 +34,11 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
 
   get isUpdating => widget.initialSettings != null;
 
-  get isOwner => !isUpdating || widget.initialSettings.isOwner;
+  get isAdmin => !isUpdating || widget.initialSettings.isAdmin;
 
   Conversation get _initialSettings => widget.initialSettings;
 
-  bool get _canAddMembers => isOwner || _initialSettings.canEveryoneAddMembers;
+  bool get _canAddMembers => isAdmin || _initialSettings.canEveryoneAddMembers;
 
   @override
   void initState() {
@@ -68,7 +66,7 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
               decoration: InputDecoration(
                 labelText: tr("Conversation name (optionnal)"),
                 alignLabelWithHint: true,
-                enabled: isOwner,
+                enabled: isAdmin,
               ),
             ),
 
@@ -90,7 +88,7 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
               children: <Widget>[
                 Switch.adaptive(
                   value: _canEveryoneAddMembers,
-                  onChanged: isOwner
+                  onChanged: isAdmin
                       ? (b) => setState(() {
                             _canEveryoneAddMembers = b;
                           })
@@ -126,7 +124,7 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
                                   PopupMenuItem(
                                     child: Text(tr("Remove")),
                                     value: _MembersMenuChoices.REMOVE,
-                                    enabled: isOwner ||
+                                    enabled: isAdmin ||
                                         (_canEveryoneAddMembers &&
                                             !_initialSettings.members
                                                 .contains(f.id)),
@@ -163,7 +161,8 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
 
   /// Submit the conversation
   Future<void> _submitForm() async {
-    final settings = Conversation(
+    // TODO : reimplement
+    /* final settings = Conversation(
         id: isUpdating ? widget.initialSettings.id : 0,
         ownerID: isUpdating ? widget.initialSettings.ownerID : 0,
         name: _nameController.text,
@@ -198,6 +197,6 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
 
     MainController.of(context).popPage();
     if (!isUpdating)
-      MainController.of(context).openConversation(conversationID);
+      MainController.of(context).openConversation(conversationID);*/
   }
 }

lib/ui/tiles/conversation_message_tile.dart

@@ -1,7 +1,6 @@
 import 'package:comunic/models/conversation_message.dart';
 import 'package:comunic/models/user.dart';
 import 'package:comunic/ui/widgets/account_image_widget.dart';
-import 'package:comunic/ui/widgets/network_image_widget.dart';
 import 'package:comunic/ui/widgets/text_widget.dart';
 import 'package:comunic/utils/date_utils.dart';
 import 'package:comunic/utils/intl_utils.dart';
@@ -72,7 +71,9 @@ class ConversationMessageTile extends StatelessWidget {
 
   /// Build widget image
   Widget _buildMessageImage(BuildContext context) {
-    return Container(
+    return Text("");
+    // TODO : fix file
+    /*return Container(
       margin: EdgeInsets.only(bottom: 2),
       child: NetworkImageWidget(
         url: message.imageURL,
@@ -80,7 +81,7 @@ class ConversationMessageTile extends StatelessWidget {
         width: 200,
         height: 200,
       ),
-    );
+    );*/
   }
 
   /// Build message date

lib/ui/tiles/conversation_tile.dart

@@ -80,7 +80,7 @@ class ConversationTile extends StatelessWidget {
         crossAxisAlignment: CrossAxisAlignment.stretch,
         children: <Widget>[
           _buildSubInformation(
-              Icons.access_time, diffTimeFromNowToStr(conversation.lastActive)),
+              Icons.access_time, diffTimeFromNowToStr(conversation.lastActivity)),
           _buildSubInformation(
             Icons.group,
             conversation.members.length == 1

lib/ui/widgets/posts_list_widget.dart

@@ -119,33 +119,36 @@ class PostsListWidgetState extends SafeState<PostsListWidget> {
 
     _loading = true;
 
-    final list = !getOlder
+    try {
-        ? await widget.getPostsList()
+      final list = !getOlder
-        : await widget.getOlder(_list.oldestID);
+          ? await widget.getPostsList()
+          : await widget.getOlder(_list.oldestID);
 
-    if (list == null) return _loadError();
+      if (list == null) return _loadError();
 
-    final users = await _usersHelper.getList(list.usersID);
+      final users = await _usersHelper.getList(list.usersID);
 
-    if (users == null) return _loadError();
+      final groups = await _groupsHelper.getList(list.groupsID);
 
-    final groups = await _groupsHelper.getList(list.groupsID);
+      if (groups == null) return _loadError();
 
-    if (groups == null) return _loadError();
+      if (!mounted) return;
 
-    if (!mounted) return;
+      setState(() {
-
+        if (!getOlder) {
-    setState(() {
+          _list = list;
-      if (!getOlder) {
+          _users = users;
-        _list = list;
+          _groups = groups;
-        _users = users;
+        } else {
-        _groups = groups;
+          _list.addAll(list);
-      } else {
+          _users.addAll(users);
-        _list.addAll(list);
+          _groups.addAll(groups);
-        _users.addAll(users);
+        }
-        _groups.addAll(groups);
+      });
-      }
+    } catch (e, s) {
-    });
+      print("Failed to load post information ! $e => $s");
+      _loadError();
+    }
 
     _loading = false;
   }

lib/ui/widgets/tablet_mode/conversations/conversation_window.dart

@@ -81,7 +81,7 @@ class _ConversationWindowState extends SafeState<ConversationWindow> {
     _refresh();
 
     listen<NewConversationMessageEvent>((e) {
-      if (e.msg.conversationID == _convID &&
+      if (e.msg.convID == _convID &&
           _collapsed &&
           e.msg.userID != userID()) setState(() => _hasNewMessages = true);
     });

lib/utils/conversations_utils.dart

@@ -10,16 +10,16 @@ import 'package:flutter/material.dart';
 
 /// Open a private conversation with a given [userID]
 Future<bool> openPrivateConversation(BuildContext context, int userID) async {
-  final convID = await ConversationsHelper().getPrivate(userID);
+  try {
+    final convID = await ConversationsHelper().getPrivate(userID);
 
-  if (convID == null) {
+    // Open the conversation
+    MainController.of(context).openConversation(convID);
+
+    return true;
+  } catch (e, s) {
+    print("Failed to find private conversation! $e => $s");
     showSimpleSnack(context, tr("Could not find a private conversation!"));
     return false;
   }
-
-  // Open the conversation
-  MainController.of(context).openConversation(convID);
-
-  // Success
-  return true;
 }

pubspec.lock

@@ -346,7 +346,7 @@ packages:
     source: hosted
     version: "1.8.0-nullsafety.1"
   path_provider:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: path_provider
       url: "https://pub.dartlang.org"

pubspec.yaml

@@ -11,7 +11,7 @@ description: Comunic client
 # In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
 # Read more about iOS versioning at
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
-version: 1.1.1+5
+version: 1.1.2+6
 
 environment:
   sdk: ">=2.1.0 <3.0.0"
@@ -91,6 +91,8 @@ dependencies:
   # Version manager
   version: ^1.2.0
 
+  path_provider: ^1.6.27
+
 dev_dependencies:
   flutter_test:
     sdk: flutter