Flutter / Firebase Firestore : How to create a book tracking system?-CodePudding

I have an app in Flutter where users can add some book chapters to their profile and read it. Now I want to create a training system when the user has read a chapter, the app marks it as read. I'm using Firebase Firestore like this

I was thinking to add a "read" field in the chapter document but it will result in every user will have the mark "read" in the app.

So, how to create a tracking system that allows marking read chapters just for the current user?

CodePudding user response：

The best option that you have is to store all those chapters in an array in the user object:

$uid (document)
 |
 --- chapters: ["Cross Guild", "Other Cross Guild"]

Or in a Map:

$uid (document)
 |
 --- chapters (map)
       |
       --- Cross Guild: true
       |
       --- Other Cross Guild: true

I will have 10.000 chapters.

If you're afraid about the 1 MiB maximum limitation of a document, then I recommend you create a document for the starting letter of a chapter:

Firestore-root
  |
  --- chapters (collection)
        |
        --- aChapters (document)
        |     |
        |     --- //Array or Map of chapters starting with the letter a.
        |
        --- bChapters (document)
              |
              --- //Array or Map of chapters starting with the letter b.

In this way, you'll be able to store 26 MiB of data, which is pretty much.

CodePudding user response：

You need to create such field for users collection. For example, creating "read chapters" named field (readed is not grammatically correct) which is an array, accepting String. If a user read, then you add this chapter's name to this user's doc(to "read chapters" field I mean). So you can check like that, array.contains("chapter_name") and mark the chapter as read or unread. That is all.