Read/Unread - JobChat notifications - Back end

[camerojo]

Each chat will have a toggling button "Mark read/unread" (or something equivalent)

Clicking that button will send a message to the server, updating the database recording whether or not the chat has been read by the user.

The data can be stored in a table UserReadChat which stores an entry for each chat read by a user

user/chat/timestamp(or last read post id)

That entry records that the user has indicated that they have read the chat.

When a new post is made on a chat, all entries for that chat will be removed from the table - because the chat now contains new information unread by any user.

On the front end, a new component can be created which monitors and displays the read/unread status of a chat. Instances of this component are used to notify the user of new chat posts that they have not read. It may simply display an asterisk (for example) indicating that the chat has unread posts. This component queries the initial "read status" of the chat (from the UserReadChat table on the server), and then subscribes to the stream of post updates received by subscribing to the chat, merged with a stream of "user read chat" events. The latter stream is generated completely locally from the Angular code (rather than events from the server). The component subscribes to the stream when it is displayed, an unsubscribes when it is not displayed. A new chat post causes the component to display "unread", a "user read chat" event causes the component to display "read". @sadatmalik

Originally posted by @camerojo in https://github.com/Talent-Catalog/talentcatalog/issues/445#issuecomment-1826731942

[camerojo]

See https://github.com/Talent-Catalog/talentcatalog/issues/445#issuecomment-1837585681 and https://github.com/Talent-Catalog/talentcatalog/issues/445#issuecomment-1880473031

[camerojo]

• [x] Refreshing browser causes cleanup of CatService triggered by phantom logout
• [x] ChatReadStstus not working at logon - suspect use of isChatRead in ngOnChnages - should leave setting of indicator just to obeservables
• [x] Intellij is using CandidatePortal ChatService in admin portal - invalidated caches - rebuilding.

[camerojo]

Bug with browser refresh or initial login

• [x] Check latest version of rxjs. 6.5.5. Note that latest versions 7.x are not supported by Angular until version 12.2.x. https://gist.github.com/LayZeeDK/c822cc812f75bb07b7c55d07ba2719b3
• [x] For switched Observables, need to store the final observable after any piping, otherwise the pipe logic gets done on each subscribe.
• [ ] Copy admin chat.service to candidate portal
• [ ] Receiving multiple posts in tap - even though only one post message is sent out.
• [ ] Window of error - see Todo in ChatService. This is happening when multiple chats are requested. The first one is different: a two stage process,

I think what I need is a Hot observable. See https://www.learnrxjs.io/learn-rxjs/operators/multicasting - in particular some of the Additional resources. Including Ben Lesh.