Implementation of notifications

[JonasMuehlmann]

Concept:

• Save unread notifications in Database
• Users can customize their notification settings to:
  • Mute specific notification events (What happened?)
  • Mute specific notification sources (Where did it happen?)
  • Mute specific notification senders (Who triggered the event?)
• The notification type can be represented as an enum
• The content can be stored in the JSON format and parsed depending on the type

CREATE TABLE NotificationType(
ID int IDENTITY(1,1) PRIMARY KEY,
Type NVARCHAR(30) NOT NULL
);

CREATE TABLE Notifications(
ID int IDENTITY(1,1) PRIMARY KEY,
RecipientId NVARCHAR(64)  COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL FOREIGN KEY REFERENCES Users(UserId),
Message NVARCHAR(200) NOT NULL,
CreationTime date NOT NULL,
);

Create Table NotificationMutes(
	Id Int IDENTITY(1,1),
	NotificationType NVARCHAR(64),
	NotificationSourceType NVARCHAR(64) ,
	NotificationSourceValue NVARCHAR(64),
	UserId NVARCHAR(64) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL FOREIGN KEY REFERENCES Users(UserId),
      SenderId NVARCHAR(64) COLLATE SQL_Latin1_General_CP1_CI_AS FOREIGN KEY REFERENCES Users(UserId)
);

ALTER TABLE Mentions Add mentionerId NVARCHAR(64) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL FOREIGN KEY REFERENCES users(userId);


INSERT INTO NotificationType VALUES('UserMentioned');
INSERT INTO NotificationType VALUES('MessageInSubscribedChannel');
INSERT INTO NotificationType VALUES('MessageInSubscribedTeam');
INSERT INTO NotificationType VALUES('MessageInPrivateChat');
INSERT INTO NotificationType VALUES('InvitedToTeam');
INSERT INTO NotificationType VALUES('RemovedFromTeam');
INSERT INTO NotificationType VALUES('ReactionToMessage');
INSERT INTO NotificationType VALUES('MessageDeleted');

Backend tasks:

• Create NotificationService
  • Send notification
  • Retrieve notification
  • Mark notification as read
• Create Notification Model
• Adjust DB
• Notification message builders
• muting functionality
• testing

Frontend tasks:

• Notification view
• Navigation to event source (e.g. team)
• Notification settings view
• Notification constructors
• Check for user being offline or in the wrong view
• Integrate notification sending with SignalR events

Notes for frontend implementation:

• I recommend having a function like void AddNotification(Notification notification) that calls an internal T BuildNotificationMessage(JObject message) method which looks up the appropriate parser in A Dictionary<NotificationType, Func<NotificationType, T>> and returns a notification message.
• Where T = An UI element for the notification

[JayKim94]

Partially implemented (new team invited, message while absent) by #323