Open private conversation from friends list

lib/helpers/conversations_helper.dart

@@ -58,8 +58,7 @@ class ConversationsHelper {
 
     final response = await request.exec();
 
-    if(response.code != 200)
-      return false;
+    if (response.code != 200) return false;
 
     //Delete old conversation entry from the database
     await _conversationsDatabaseHelper.delete(settings.id);
@@ -160,6 +159,30 @@ class ConversationsHelper {
     return name;
   }
 
+  /// 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
+  Future<int> getPrivate(int userID, {bool allowCreate = true}) async {
+    final response = await APIRequest(
+      uri: "conversations/getPrivate",
+      needLogin: true,
+      args: {
+        "otherUser": userID.toString(),
+        "allowCreate": allowCreate.toString()
+      },
+    ).exec();
+
+    if (response.code != 200) return null;
+
+    // Get and return conversation ID
+    try {
+      return int.parse(response.getObject()["conversationsID"][0]);
+    } catch (e) {
+      e.toString();
+      return null;
+    }
+  }
+
   /// Asynchronously get the name fo the conversation
   ///
   /// Unlike the synchronous method, this method does not need information