onAttachedToRootStore triggers after user-land reactions

[Amareis]

Currently this hook fired after parent action has ended. In my app there is some corner case, where other reactions fired after action bounds, but before hook, and this is not really good, because there is chance to access partial-initialised model, which depends on root store.

[xaviergonz]

Could you elaborate (with an example if possible)?

[xaviergonz]

By the way, onAttachedToRootStore was changed to run after the current action is finished because of this: https://github.com/xaviergonz/mobx-keystone/issues/103

[Amareis]

Could you elaborate (with an example if possible)?

Sure, https://codesandbox.io/s/mobx-keystone-lazy-attached-problem-fxfd7 Parent already accessible, but hook is not fired yet. In my project it cause problem, because root store contains some environment data, which is needed by some computed values, which is triggered by external watchers, just as in example. Currently I workaround this with a getParentOfType, but I certainly think that current behavior is confusing.

[xaviergonz]

What if you use const attached = !!getRootStore(this) instead of this.attached? would that solve your use case?

[xaviergonz]

Actually the issue in the example seems to be that it is missing

registerRootStore(r); // you forgot this line

after that change it shows true when logging this.attached.

https://codesandbox.io/s/mobx-keystone-lazy-attached-problem-forked-tnr4h?file=/src/index.tsx:879-949

[xaviergonz]

Can you try "0.45.3-alpha.0"? It is a version that still runs onAttachedToRootStore after all model actions are finished, but before all "user" reactions are run

[Amareis]

Uh-oh, my bad, totally forgot about registerRootStore. But still, there is simple reproduction: https://codesandbox.io/s/mobx-keystone-lazy-attached-problem-forked-o1n7o?file=/src/index.tsx

[Amareis]

And yep, with latest keystone problem solved!

[xaviergonz]

Nice, the fix should be out now in 0.45.3 :)

[Amareis]

Thank you!