[Bug?] Issues with using hooks

[JakeHadley]

I'm working on animating an icon with hooks and react-native-animatable but I'm getting an error using the useRef hook. The error is undefined is not an object (evaluating 'iconRef.current.animatable.transitionTo').

I'm trying to figure out if this is an issue with the library or with how I'm using useRef or the library method. In the end, I want the icon to rotate when the button is pushed.

Reproducible snack here

import * as React from 'react';
import { Text, View, StyleSheet, TouchableOpacity } from 'react-native';
import Constants from 'expo-constants';
import Icon from 'react-native-vector-icons/Entypo';
import * as Animatable from 'react-native-animatable';
const AnimatedIcon = Animatable.createAnimatableComponent(Icon);

const App = () => {
  const iconRef = React.useRef(null);
  const [rotated, setRotated] = React.useState(true);

  return (
    <View>
      <TouchableOpacity
        style={styles.container}
        onPress={() => {
          setRotated(!rotated);
          iconRef.current.animatable.transitionTo({
            transform: rotated ? [{ rotate: '0deg' }] : [{ rotate: '90deg' }],
          });
        }}>
        <Text style={{ fontSize: 30 }}>Press Me</Text>
      </TouchableOpacity>
      <AnimatedIcon
        name="chevron-small-right"
        ref={iconRef}
        size={50}
        style={{
          transform: [{ rotate: '0deg' }],
        }}
      />
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    paddingTop: Constants.statusBarHeight,
    backgroundColor: '#ecf0f1',
    padding: 8,
    marginTop: 50,
  },
});

export default App;

[danstepanov]

Using const animationRef = useRef(), I'm able to reference the component via animationRef.current.fadeOutUp()

[mohmdalfaha]

I am facing the same issue, I have the exact thing @danstepanov mentioned with no hope.

[mohmdalfaha]

I resolved my issue which happened because I was giving a condition before the animatble.view to appear

eg:-

{
cart.total.length  > 0 && 
<Animatble.View ref={animationRef}>
 <Text> cart.total </Text>
</Animatble.View>
}

So your animation won't be applied in this case.

Instead, I changed the way the condition is applied like so:-

<Animatble.View 
style={{opacity: cart.total > 0 ? 1 : 0}}
ref={animationRef}>
 <Text> cart.total </Text>
</Animatble.View>

Then It worked nicely

Hope this helps someone :)

[willryanuk]

Yeah, if the Animatable.View isn't there on first load, then the useEffect callbacks just don't work (the current ref is not there). Quite a bit bug, and had me confused for quite a while.