[discussion] Update ReSub to support the latest React

The latest version of React (starting from 16.3.*) includes public API changes which will affect on the ReSub in the future.

The following methods will be removed:

• componentWillMount
• componentWillUpdate
• componentWillReceiveProps - has new pseudo analog, static method getDerivedStateFromProps

In my opinion, the most significant change related to componentWillMount, because ReSub uses it to set the initial state., correct me if I’m wrong.

In order to use the latest version of React with ReSub would be great to follow new API changes.

Is there any plan/ideas on how to “smoothly” update ReSub? Maybe make sense to make all changes and publish major (for instance 2.0) version in order to do not break applications which use the current version of ReSub.

What do you think @deregtd @ms-markda @berickson1?

[dryganets]

I’m going to figure out a solution in a next couple days. React 16.4 already warns about methods usage, I guess we will have 3 different configuration options for different React versions.

1. As is. for react < 16.3, marked as deprecated
2. Unsafe methods version for react < 17, marked as will be deprecated soon
3. Static life cycle version recommended for usage

I’m going to use 2nd for our upgrade to react-native 0.56 to don’t have too many changes and speed up the bump and as a following change - update it to 3rd.

I need to experiment with getDerivedStateFromProps a bit. If I remember correctly it is called on initial component creation and where componentWillReceiveProps and componentWillMount were called.

My understanding is that the method might be called more frequently than it used to due to the fiber related changes. I’m not sure if this part is already implemented in react. They stated that they are going to apply some optimizations which might cause multiple method calls that’s why the original methods got deprecated.

[BiggA94]

I have already done some prototyping see Pull Request. I tried not to change the API of ReSub. You cann tell me, what you think about it.