[3.16.1] NativeWind classes not being applied on Animated.View

[amandaharlin]

Description

React-Native-Reanimated (at 3.10.1) was working with NativeWind to correctly apply classes to an Animated.View.

After upgrading Reanimated to 3.16.1 NW classnames were no longer getting applied to an Animated.View.

I opened a ticket with NativeWind too, so both teams could be notified.

Working Project Details	Not-Working Project Details
Expo 52.0.0-preview.18	Expo 52.0.0-preview.18
React NativeReanimated 3.10.1	React NativeReanimated at 3.16.1
NativeWind at 4.1.21	NativeWind at 4.1.21

rnreanimated 3.10.1	rnreanimated 3.16.1

Steps to reproduce

1. Create a repo with npx create-expo-stack@latest --nativewind
2. Upgrade Reanimated from 3.10.1 to 3.16.1
3. Add classNames to an animated view. (Should work, but does not)
4. Downgrade Reanimated to 3.10.1. (Works as expected)

Snack or a link to a repository

https://github.com/amandaharlin/react-native-reanimated-nativewind-classname-repro

Reanimated version

3.16.1

React Native version

0.76.1

Platforms

Web

JavaScript runtime

None

Workflow

Expo Go

Architecture

None

Build type

Debug app & dev bundle

Device

None

Device model

No response

Acknowledgements

Yes

[marklawlor]

I have no investigated this yet. But incase this is a reanimated issue, NativeWind on web works by passing a StyleQ precompiled styled object to the <View />.

<View style={{ $$css: true, myUniqueIdentifier: 'my-class' }} /> 

will output as 

<div class="my-class" />

[amandaharlin]

Hey y'all, after checking 3.12, 3.14, and 3.15.5, I found that the change appeared in 3.16.0.

[marklawlor]

This issue is caused by how react-native-reanimated builds in 3.1.16.

NativeWind relies on a jsx transform (turning <View> -> jsx(View), where it needs to use the jsx function from NativeWind.

3.1.16 is being published to NPM with the jsx function being hardcoded to react/jsx-runtime. This also means that react-native-reanimated will not work with libraries like @emotion/native which relies on the jsx transform.

I'm not actually sure why this is happeneding, as the tsconfig.json#jsx is correctly set to react-native, which should preserve the JSX.

A work around is to simply not use Animated.View. You can just use a View and add an animation class to it like animate-none, and NativeWind will turn your View into an Animated.View

[amandaharlin]

@marklawlor Thank you for checking this out and sharing that alternative. That is useful in many situations, but there's some situations where we needed lower level control to do something more precisely. These are instances where tailwind isn't driving the animation, we're just adding additional tailwind classes and the javascript calculations are driving the animation (e.g. moving a box around in absolute space, relying on screen measurements, but also needs some tailwind classes, like flex, typography, or a background color, applied to an element; classes unrelated to that animation).

What we're trying for now in those places is we're implementing the first workaround where you're using the object to set style (with a ts-ignore). In this situation the class is applied correctly to the animated view, instead of using the more convenient classname property. In situations where it looks like the animation view can be swapped for a view and transpiled to a view, we're doing that too. Thanks again for your OSS work, both of y'all, and all your help.

[marklawlor]

Another workaround is to use

const MyAnimatedView = cssInterop(Animated.View, { className: "style" })

<MyAnimatedView />

[amandaharlin]

Thanks! That works great. Here's my full cross-platform component in typescript.

animated-view.web.tsx

import Animated from 'react-native-reanimated';
import type { ViewProps } from 'react-native';
import type { AnimatedProps } from 'react-native-reanimated';
import { cssInterop } from 'nativewind';
import { cn } from '~/lib/utils';

const InteropAnimatedView = cssInterop(Animated.View, { className: 'style' }); 

export const AnimatedView = ({ className, ...animatedViewProps }: AnimatedProps<ViewProps>) => {
  return <InteropAnimatedView {...animatedViewProps} className={cn(className)} />;
};

animated-view.tsx

import Animated from 'react-native-reanimated';

export const AnimatedView = Animated.View;

utils.tsx

import type { ClassValue } from 'clsx';
import { clsx } from 'clsx';
import { twMerge } from 'tailwind-merge';

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs));
}

implementation.tsx

import Animated, { useAnimatedStyle } from 'react-native-reanimated';
import { AnimatedView } from '~/components/ui/animated-view';

const viewStyle = useAnimatedStyle(() => { 
/// interpolate here
}) 

<AnimatedView style={viewStyle} className="flex items-center justify-center">
  <View/>
</AnimatedView>

I'm using this with expo. It was working correctly on iOS and Android, this code snippet implements the change for the web build. With the .web switch, this puts them at feature parity.

Would you like for this to be the official way to use RNReanimated and NW? I can make a PR to the NW docs, which would close this issue.

[marklawlor]

cssInterop returns a new component. Calling it during render will always cause a remount of that component (as your rendering something different everytime)

[amandaharlin]

I wanted to provide a quick update here, firstly

import Animated from 'react-native-reanimated';
import type { ViewProps } from 'react-native';
import type { AnimatedProps } from 'react-native-reanimated';
import { cssInterop } from 'nativewind';
import { cn } from '~/lib/utils';

//move to here
const InteropAnimatedView = cssInterop(Animated.View, { className: 'style' }); 

export const AnimatedView = ({ className, ...animatedViewProps }: AnimatedProps<ViewProps>) => {
  //const InteropAnimatedView = cssInterop(Animated.View, { className: 'style' }); 
  return <InteropAnimatedView {...animatedViewProps} className={cn(className)} />;
};

this works just fine after testing, and should avoid the performance pitfall you mention, so I've updated my code snippet

That said, i've not yet updated my reproduction repo, but the mobile behavior has actually degraded more from the time I posted this issue. I had been using

import Animated from 'react-native-reanimated';
export const AnimatedView = Animated.View;

and this was working beforehand on the mobile platforms. Now, when I use that code or if I use the css Interop approach for mobile, neither one is working. While trying to zero in on "what changed", I can see that I haven't changed nativewind or react-native-reanimated but expo did update. I can't see immediately how that could cause this issue, so I am still investigating. That said, last week iOS and Android were working (and only web needed to be shimmed), now mobile doesn't work at all, but the fix upthread for web does still work great for web builds, and seems to have no effect on mobile.

To get around this I've fallen back to just specifying css properties with the standard JSON syntax on the style prop for now.

[marklawlor]

This issue is an upstream bug with react-native-builder-bob callstack/react-native-builder-bob#678

I've the issue isn't addressed soon then I'll probably adjust the nativewind babel plugin to work around it

[kaumac]

I'm having the same problem, I was using Moti (which uses Reanimated under the hood) and classNames were working fine.
After upgrading Reanimated the classNames stopped working. I then tried using just raw Reanimated and it was the same problem (worked before 3.16.1 and stopped working after that).

For now I've been using just plain style={{}}

I don't fully understand from the conversation if we'll be able to just use classNames on the animated View directly or if creating a custom cssInterop wrapper is the way to go moving forward?

[tjzel]

@marklawlor @amandaharlin Thanks for troubleshooting this!

[focux]

Is there a workaround that we can apply meanwhile? I have a big codebase with many animated views and would be a pain to change all those views to use a style object until this is fixed.

@marklawlor would patching the react-native-builder-bob babel-preset fix the issue?