Does mobx-react produces reactions in Unmounted Components?

[jmaguirrei]

Hello

I noticed reactions in components that are not rendered in the screen.
I putted a console.login render() function and get those logs.
Even though this components are observers of data that has mutated, they are not rendered, so (I think) they should not react...

Is it possible to prevent this?

[andykog]

@jmaguirrei, if render() is being called, then your components are being rendered somewhere

[andykog]

You can try placing console.log(this._reactInternalInstance._nativeParent._currentElement) in those render(). It might help you find out who is rendering your component (or might not).

[jmaguirrei]

@andykog Thanks, I found in one case those components were hidden because they are animated from 0 to 1 scale...

But, I have another case that calls render() and I think they should not.

For example, I have this (simplified) component tree:

Main (observes and passes A & B)

• Header (receives and observes 'A')
• List (receives and observes 'B')

'A' changes, Main is re-rendered, Header is re-rendered, but List is also re-rendered (I mean render is called but no DOM is changed).

I can control List not to re-render with some 'ad-hoc' ShouldComponentUpdate, but I like to rely on mobx-react to do that.

How could achieve that?

[jmaguirrei]

Closing this, no evidence that unmounted components are rendered, thans for the whole explanation

[andykog]

'A' changes, Main is re-rendered, Header is re-rendered, but List is also re-rendered (I mean render is called but no DOM is changed).

Removed misleading comments about forceUpdate. We have discovered, that this is happening because List doesn't have pure rendering implemented. That can be achieved either with decorating List with @observable (that implements pureRenderMixin), or just using something like https://www.npmjs.com/package/pure-render-decorator for LIst