How do I mutate an object inside of an array?

[samskiter]

Is mutating an item inside of an array, like this todoStore.todos[index].setDone(true) supported?

export class TodoModel extends Model({
  todos: prop<Todo[]>(() => []).withSetter(),
})

I'm finding that this isn't consistently working, especially after first adding a new Todo to the model

[samskiter]

This works, but the above indexing doesn't:

arrayActions.set(todoStore.todos, index, new Todo({
    done: true,
}))

[xaviergonz]

todoStore.todos[index].setDone(true) should work

[samskiter]

Aha - I wonder if it's related to this: https://github.com/xaviergonz/mobx-keystone/issues/173

My todo was created like

export class Todo extends Model({
  done: prop<bool>().withSetter(),
}) {
  static defaultTodo() {
    return new Todo({ done: false })
  }
}

export class TodoModel extends Model({
  todos: prop<Todo[]>(() => []).withSetter(),
}) {
  @modelAction
  addNewTodo() {
  this.setTodos([...this.todos, Todo.defaultTodo()])
}

But If i change to this, things start working:

export class Todo extends Model({
  done: prop<bool>().withSetter(),
})

export class TodoModel extends Model({
  todos: prop<Todo[]>(() => []).withSetter(),
}) {
  @modelAction
  addNewTodo() {
  this.setTodos([...this.todos, new Todo({ done: false })])
}

[xaviergonz]

Sounds like you found it :)

[samskiter]

Yes, but unsure why a static factory method wouldn't work!

On Mon, 17 Jun 2024, 18:34 Javier Gonzalez, @.***> wrote:

Sounds like you found it :)

— Reply to this email directly, view it on GitHub https://github.com/xaviergonz/mobx-keystone/issues/545#issuecomment-2173961494, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAJWOW3EGF6KAM4SOISRURLZH4MYRAVCNFSM6AAAAABJOMQEFSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDCNZTHE3DCNBZGQ . You are receiving this because you authored the thread.Message ID: @.***>

[xaviergonz]

It works if you use anything other than babel to transpile the legacy decorators (e.g. typescript compiler) and potentially it might work even with babel if you use the new decorators.

[samskiter]

Hrmm, I'm not consciously using Babel - I've never even heard of it. Can you point me at something to read up?

On Mon, 17 Jun 2024, 19:14 Javier Gonzalez, @.***> wrote:

It works if you use anything other than babel to transpile the legacy decorators (e.g. typescript compiler) and potentially it might work even with babel if you use the new decorators.

— Reply to this email directly, view it on GitHub https://github.com/xaviergonz/mobx-keystone/issues/545#issuecomment-2174031977, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAJWOW3FSNG6CZUUNGHSVDDZH4RRJAVCNFSM6AAAAABJOMQEFSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDCNZUGAZTCOJXG4 . You are receiving this because you authored the thread.Message ID: @.***>