Can update a conversation message

lib/helpers/conversations_helper.dart

@@ -292,6 +292,13 @@ class ConversationsHelper {
               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
   Future<SendMessageResult> sendMessage(NewConversationMessage message) async {
     final request = APIRequest(
@@ -320,27 +327,34 @@ class ConversationsHelper {
     return SendMessageResult.SUCCESS;
   }
 
+  /// Update a message content
+  Future<bool> updateMessage(int id, String newContent) async {
+    final response = await APIRequest(
+        uri: "conversations/updateMessage",
+        needLogin: true,
+        args: {"messageID": id.toString(), "content": newContent}).exec();
+
+    if (response.code != 200) return false;
+
+    // Update the message content locally
+    return await _conversationMessagesDatabaseHelper.updateMessageContent(
+        id: id, newContent: newContent);
+  }
+
   /// Delete permanently a message specified by its [id]
   Future<bool> deleteMessage(int id) async {
-
     // Delete the message online
     final response = await APIRequest(
-      uri: "conversations/deleteMessage",
-      needLogin: true,
-      args: {
-        "messageID": id.toString()
-      }
-    ).exec();
-
-    if(response.code != 200) return false;
+        uri: "conversations/deleteMessage",
+        needLogin: true,
+        args: {"messageID": id.toString()}).exec();
 
+    if (response.code != 200) return false;
 
     // Delete the message locally
     return await _conversationMessagesDatabaseHelper.delete(id);
-
   }
 
-
   /// Turn an API response into a ConversationMessage object
   ConversationMessage _apiToConversationMessage({
     @required int conversationID,

lib/helpers/database/conversation_messages_database_helper.dart

@@ -2,6 +2,7 @@ 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';
+import 'package:meta/meta.dart';
 
 /// Conversation messages database helper
 ///
@@ -34,4 +35,26 @@ class ConversationMessagesDatabaseHelper
     finalList.addAll(list);
     return finalList;
   }
+
+  /// Update the content of a message
+  Future<bool> updateMessageContent({
+    @required int id,
+    @required String newContent,
+  }) async {
+    assert(id != null);
+    assert(newContent != null);
+
+    final message = await get(id);
+
+    if(message == null)
+      return false;
+
+    // Update the conversation message using the map
+    final map = message.toMap();
+    map[ConversationsMessagesTableContract.C_MESSAGE] = newContent;
+
+    await insertOrUpdate(ConversationMessage.fromMap(map));
+
+    return true; // Success
+  }
 }