Is that possible to update ModelContainer?

Question

Dec2025 OP

Created 21h

Replies 2

Boosts 0

Participants 2

Here is what I thought

I want to give each user a unique container, when the user login or register, the user could isolate their data in specific container.

I shared the container in a singleton actor, I found it's possible to update the container in that actor.

But I think it won't affect the modelContext which is in the Environment.

Does SwiftData allow me or recommend to do that?

Answered by DTS Engineer in 864654022

Technically, it's totally fine that your app replaces an existing model container with a new one, or use multiple containers. Just be sure that you update with the appropriate container for your views and scene via their modelContainer(_:) method. When that is done, the model context injected to the environment of the view hierarchy should change automatically, which triggers an update for the view hierarchy.

Practically, I'd probably only do that if every user has their own store (so I need to switch to another store when a user login happens). Sharing one single model container across an app is good enough for most cases, and makes things simpler.

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.

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Answer 1

DTS Engineer OP

Apple

17h

Recommended

Technically, it's totally fine that your app replaces an existing model container with a new one, or use multiple containers. Just be sure that you update with the appropriate container for your views and scene via their modelContainer(_:) method. When that is done, the model context injected to the environment of the view hierarchy should change automatically, which triggers an update for the view hierarchy.

Practically, I'd probably only do that if every user has their own store (so I need to switch to another store when a user login happens). Sharing one single model container across an app is good enough for most cases, and makes things simpler.

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.

1

Answer 2

Dec2025 OP

9h

Thank you, I tried, and I think the key is modelContainer(_:) method

Now I have login and register view inside my MainScreenView. MainScreenView is the top View, which uses modelContainer(_:) method inject the container to the View, and the container is saved in a singleton actor.

So the injection is finished right now, although I changed the container in singleton actor, that's the reason it won't affect anything.

I think what I should do is, separate the inject, rearrange the hierarchy, make sure when MainScreen is open it could access the new Container, am I right?

BTW, I have some data which happened before register, when registration is done, I want to save that data to a new Container, and I got illegal inject error.

So it's not possible to save the model data from another ModelContext to a new ModelContext, is that right? I should save them to another format then transfer to Model Data.

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