React navigation with hooks and header function - state is not updating - reactjs

Question

Trying to use react navigation with hooks and a button in the navigation header.
I can pass the handleShowModalLogin function to the navigation header and I can see the button is clicked, but the problem is the setShowLoginModal is not updating the showLoginModal state to true. Not sure why this is not working.
import React, { useState, useEffect, useLayoutEffect } from "react";
import {
Image,
Platform,
ScrollView,
StyleSheet,
Text,
TouchableOpacity,
View,
Button,
} from 'react-native';
import LoginModal from './users/LoginModal';
const HomeScreen = ({navigation}, props) => {
const [showLoginModal, setShowLoginModal] = useState(false);
const handleShowModalLogin = (value) => {
console.log("showLoginModal button clicked: ", value)
if(value === "on"){
setShowLoginModal(true);
}else{
setShowLoginModal(false);
}
}
useEffect(() => {
console.log('navigation handler set with showLoginModal set:', showLoginModal)
navigation.setParams({ handleShowModalLogin: handleShowModalLogin });
}, []);
useEffect(() => {
console.log("showLoginModal value changed: ", showLoginModal), [showLoginModal]
})
return (
<View style={styles.container}>
<LoginModal showLoginModal={showLoginModal} />
<ScrollView
style={styles.container}
contentContainerStyle={styles.contentContainer}>
</ScrollView>
</View>
);
};
HomeScreen.navigationOptions = ({ navigation }) => ({
title: "Home",
headerRight: (
<View style={styles.headerComContainer}>
<Button
onPress={() => {
navigation.getParam('handleShowModalLogin')('on')
}}
title="Login"
color="#841584"
accessibilityLabel="Login" />
</View>
)
});
Here's the login modal component.
import React, { useState } from "react";
import { Text, TouchableOpacity, View, ScrollView } from "react-native";
import Modal from 'modal-enhanced-react-native-web';
export default function LoginModal(props){
const [visibleModal, setModalVisible] = useState(props.showLoginModal);
return (
<View>
<Modal
isVisible={visibleModal}
onBackdropPress={() => setModalVisible(false)}
>
<View>
<Text>Hello!</Text>
<TouchableOpacity onPress={() => setModalVisible(false)}>
<View>
<Text>Close</Text>
</View>
</TouchableOpacity>
</View>
</Modal>
</View>
);
}

Answer 1

const [visibleModal, setModalVisible] = useState(props.showLoginModal);
This code in the LoginModal creates a state, who's initial initial value is props.showLoginModal. After that initial value though, there's no connection with the prop. Changing the prop later will not cause the state to change.
You seem to be trying to mix having LoginModal be a controlled component (where a parent handles the logic, and then controls it through props) and an uncontrolled component (where the component manages its own state). Instead, i'd recommend picking one or the other.
From the fact that you're trying to control it externally, it looks like you want to create a controlled component. So your login modal will need modification to have additional props to notify the parent of the clicks. Perhaps an "onBackdropPressed" and an "onClosePressed", as in:
export default function LoginModal(props){
return (
<View>
<Modal
isVisible={props.showLoginModal}
onBackdropPress={() => props.onBackdropPressed()}
>
<View>
<Text>Hello!</Text>
<TouchableOpacity onPress={() => props.onClosePressed()>
<View>
<Text>Close</Text>
</View>
</TouchableOpacity>
</View>
</Modal>
</View>
);
}
Don't forget to modify the home screen to pass those additional props in, as in:
<LoginModal
showLoginModal={showLoginModal}
onBackdropPressed={() => setShowLoginModal(false)}
onClosePressed={() => setShowLoginModal(false)}
/>