React Native TextInput Value persist when Tab is changed - javascript

I have encountered a weird issue in the newest react native where the value in the text input in a component remains when a tab is switched.
I can't figure what is going on and I thought it should re-render when tab is changed but it doesn't.
Here's my code
app.js
export default function App() {
const [tab, setTab] = useState("TAB1")
return (
<View style={styles.container}>
<View style={{ flexDirection: 'row' }}>
<TouchableOpacity
style={{ borderRadius: 5, borderWidth: 1, marginRight: 5, padding: 20 }}
onPress={() => setTab("TAB1")}
>
<Text>Tab 1</Text>
</TouchableOpacity>
<TouchableOpacity
style={{ borderRadius: 5, borderWidth: 1, padding: 20}}
onPress={() => setTab("TAB2")}
>
<Text>Tab 2</Text>
</TouchableOpacity>
</View>
<View style={{ marginTop: 20}}>
{
tab === "TAB1" ? (
<View>
<InputComponent tab={tab} />
</View>
) : (
<View>
<InputComponent tab={tab} />
</View>
)
}
</View>
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
marginTop: 100,
padding: 10
},
});
inputcomponent.js
export function InputComponent({ tab }) {
const [value, setValue] = useState("");
return (
<View>
<Text>{tab}</Text>
<TextInput placeholder="INPUT HERE" value={value} onChangeText={setValue}/>
</View>
)
}
It seems like the input component re-renders but the text input within it doesn't change.
Demo Issue

This is such a good question. This is because we are importing it once and passing it to two different components. It changes the tab but uses the same textinput state because they are using the same key.
To fix this pass in the key prop so React knows that tab changed:
{
tab === "TAB1" ? (
<View>
<InputComponent key={1} tab={tab} />
</View>
) : (
<View>
<InputComponent key={2} tab={tab} />
</View>
)
}
Snack: https://snack.expo.io/mVVLb9uId
Read about keys: https://reactjs.org/docs/lists-and-keys.html#keys

Related

How to change change and track boolean state of each element in an array

Im trying to make it so that when a TouchableHighlight is pressed in react native it goes from one colour to another. I have state that is set to false and changes when the button is pressed. However this changes the colour for all elements in the map rather than for each item individually. Is there a way to update the state for each element independently?
Here is my code:
function OnboardingVibes() {
const [pressed, setPressed] = useState(false);
return (
<View style={{marginTop: 40}}>
<Text style={{fontSize: 22, color: '#FFF', marginBottom: 16}}>Vibes</Text>
<View style={styles.buttonContainer}>
{vibes.map((vibe) => {
return (
<TouchableHighlight onPress={() => setPressed(true)} style={{backgroundColor: pressed ? '#DDD' : '#4D2C5B', margin: 4, borderRadius: 4}} key={`vibe-${vibe}`}>
<Text style={styles.vibeButton}>{vibe}</Text>
</TouchableHighlight>
)
})}
</View>
</View>
);
}
One way to do it is to move the state down so you could have individual states. When the state is true at the top-level, all child components will receive the same state.
function TouchableVibe({vibe}) {
const [pressed, setPressed] = useState(false);
return (
<TouchableHighlight
onPress={() => setPressed(true)}
style={{
backgroundColor: pressed ? "#DDD" : "#4D2C5B",
margin: 4,
borderRadius: 4,
}}
>
<Text style={styles.vibeButton}>{vibe}</Text>
</TouchableHighlight>
);
}
function OnboardingVibes() {
return (
<View style={{ marginTop: 40 }}>
<Text style={{ fontSize: 22, color: "#FFF", marginBottom: 16 }}>
Vibes
</Text>
<View style={styles.buttonContainer}>
{vibes.map((vibe) => (
<TouchableVibe key={`vibe-${vibe}`} vibe={vibe} />
))}
</View>
</View>
);
}
const [pressed, setPressed] = useState(vibes.map(e=>false));
{vibes.map((vibe, index) => {
return (
<TouchableHighlight onPress={() => {
let new_Pressed =vibes.map(e=>false)
new_pressed[index]=true;
setPressed(new_pressed);
}}
style={{backgroundColor: pressed[index]
? '#DDD'
: '#4D2C5B',
margin: 4, borderRadius: 4}} key={`vibe-${vibe}`}>
<Text style={styles.vibeButton}>{vibe}</Text>
</TouchableHighlight>
)
})}
Instead of passing in a boolean to the state, pass in the id/vibe instead, and then in your conditional logic within the map you can determine if that single item is the same as the one you've clicked.
function OnboardingVibes() {
const [pressed, setPressed] = useState('');
return (
<View style={{marginTop: 40}}>
<Text style={{fontSize: 22, color: '#FFF', marginBottom: 16}}>Vibes</Text>
<View style={styles.buttonContainer}>
{vibes.map((vibe) => {
return (
<TouchableHighlight onPress={() => setPressed(vibe)} style={{backgroundColor: pressed === vibe ? '#DDD' : '#4D2C5B', margin: 4, borderRadius: 4}} key={`vibe-${vibe}`}>
<Text style={styles.vibeButton}>{vibe}</Text>
</TouchableHighlight>
)
})}
</View>
</View>
);
}

Automatically scroll ScrollView in KeyboardAvoidingView when I add a new TextInput

I am working with a KeyboardAvoidingView and it's working perfectly fine except for one small issue. In the code below I have a TouchableOpacity that when clicked runs the function addName() which appends to an array and creates a new TextInput - basically when you click it, it adds a new TextInput to the ScrollView.
The KeyboardAvoidingView works perfectly fine except every time a new TextInput is added/rendered, I have to scroll down to see it. Do you know how I can make it automatically scroll to the bottom when a new TextInput is rendered?
Here is my code for the KeyboardAvoidingView:
<KeyboardAvoidingView
style={styles.container}
behavior={Platform.OS == "ios" ? "padding" : "height"}
>
<HeaderComponent
name={this.props.route.params.bill.barName + " Tab"}
navigation={this.props.navigation}
goHome={true}
goHomePrompt={true}
/>
<View
style={{
marginTop: 30,
marginLeft: 10,
}}
>
<Text
style={{ color: "white", fontSize: 18 }}
allowFontScaling={false}
>
Add people to split with...
</Text>
</View>
<ScrollView keyboardShouldPersistTaps={"handled"}>
{this.state.nameInput.map((value, index) => (
<View style={styles.nameContainer} key={index}>
<View
style={{
width: "90%",
}}
>
<TextInput
style={styles.textInputContainer}
value={value}
onChange={this.handleText(index)}
placeholder={"Enter name..."}
placeholderTextColor={"#333333"}
maxLength={50}
/>
</View>
<View
style={{
width: "10%",
}}
>
<TouchableOpacity
onPress={() => this.handleDelete(index)}
>
<Icon name="cancel" type="material" color="red" />
</TouchableOpacity>
</View>
</View>
))}
<TouchableOpacity onPress={() => this.addName()}>
<Text style={styles.addPerson}>+ Add Person</Text>
</TouchableOpacity>
</ScrollView>
<View style={styles.bottomContainer}>
<TouchableOpacity
style={styles.continueButton}
onPress={() => {
// filters through array to make sure there are no empty strings
let nameInput = this.state.nameInput.filter(
(name) => name !== ""
);
if (
nameInput.length > 1 &&
new Set(nameInput).size === nameInput.length
) {
this.setState({ nameInput, loading: false });
} else {
alert(
"Please make sure there are at least two people and no duplicate names!"
);
}
}}
>
<Text style={styles.continueButtonText} allowFontScaling={false}>
Continue to Split Tab
</Text>
</TouchableOpacity>
</View>
</KeyboardAvoidingView>
And here is my code for the addName() function:
addName = () => {
let nameInput = this.state.nameInput.concat("");
this.setState({
nameInput,
});
};
This page has the solution I was looking for: Is it possible to keep a ScrollView scrolled to the bottom?

Different content on React Native based on condition

on my react-native app I would like to have premium content for people who paid a subscription.
My issue is how I make the content to display as unavailable(if you are not premium ) and the same as the other content if you are premium. Basically I would like the premium content to be displayed with a "lock overlay" on it for non-premium users.
However, I do not know how I set this conditional. It is a matter of state? If yes where should be positioned this state considering that is unidirectional?
Just to be clear I will have premium and non premium content
class Browser extends Component {
scrollX = new Animated.Value(0);
renderRecommended = () => {
return (
<View style={[styles.flex, styles.column, styles.recommended]}>
<View style={[styles.row, styles.recommendedHeader]}>
<Text
style={{
fontSize: theme.sizes.font * 1.4,
alignSelf: 'center',
color: 'white',
fontFamily: 'Nunito-Bold',
}}>
Recommended
</Text>
</View>
<View style={[styles.column, styles.recommendedList]}>
<FlatList
horizontal
scrollEnabled
showsHorizontalScrollIndicator={false}
scrollEventThrottle={16}
snapToAlignment="center"
style={[styles.shadow, {overflow: 'visible'}]}
data={this.props.destinations}
keyExtractor={(item, index) => `${item.id}`}
renderItem={({item, index}) =>
this.renderRecommendation(item, index)
}
/>
</View>
</View>
);
};
renderRecommendation = (item, index) => {
const {destinations} = this.props;
const isLastItem = index === destinations.length - 1;
const {navigation} = this.props;
return (
<TouchableOpacity
onPress={() =>
this.props.navigation.navigate('PreScreen', {
item,
})
}>
<View
style={[
styles.flex,
styles.column,
styles.recommendation,
styles.shadow,
index === 0 ? {marginLeft: theme.sizes.margin} : null,
isLastItem ? {marginRight: theme.sizes.margin / 2} : null,
]}>
<ImageBackground
style={[styles.imageback]}
source={{uri: item.preview}}
/>
</View>
<View
style={[
index === 0 ? {marginLeft: theme.sizes.margin - 10} : null,
isLastItem ? {marginRight: theme.sizes.margin / 2} : null,
]}>
<Text
style={{
fontSize: theme.sizes.font * 1.25,
fontWeight: '200',
color: 'white',
marginLeft: 10,
//paddingBottom: 20,
fontFamily: 'Nunito-Bold',
}}>
{item.title}
</Text>
<Text
style={{
color: theme.colors.caption,
marginLeft: 10,
fontFamily: 'Nunito-SemiBold',
}}>
{item.location}
</Text>
</View>
</TouchableOpacity>
);
};
render() {
return (
<ScrollView style={styles.container}>
<BackgroundSvg style={styles.background} />
<ScrollView
style={styles.contentContainer}
showsVerticalScrollIndicator={false}
contentContainerStyle={{paddingBottom: theme.sizes.paddin}}>
{this.renderRecommended()}
{this.renderRecommended2()}
{/* <View style={styles.mainContainerView}>
<TouchableOpacity style={styles.singInButton} gradient>
<Text style={styles.logInText}>
Activate premium subscription
</Text>
</TouchableOpacity>
</View> */}
</ScrollView>
</ScrollView>
);
}
}
Browser.defaultProps = {
destinations: mocks,
reading: readingList,
};
export default Browser;
My code is the one on the top. Just to simplify I am accesing some elements from JSON and I am creating Flatlist based on this. What I want is is to give some of the JSON files a bolean with premium or not and in this way to make some elements available for user or not.
As part of your destinations array, for each object, you can specify a boolean field called isPremiumItem. Your users should have a boolean field like isPremiumUser to show the type of their subscription.
Then in renderRecommended method you can check the user subscription status (isPremiumUser), and also the specific item status (isPremiumItem). Then you can render accordingly.

Multiple Component with Same Function Name in React Native

I'm using react-native-material-menu's popup for showing menu options.
But the issue is, it's not working for multiple scenarios.
I mean when I click on first menu button, the same methods gets triggered and hence the same menu is opened every time.
What should be the better approach for to handle this particular scenario.
_menu = null;
setMenuRef = ref => {
this._menu = ref;
};
hideMenu = () => {
this._menu.hide();
};
showMenu = () => {
this._menu.show();
};
<FlatList
data={this.state.clientsList}
renderItem={({ item }) => {
return (
<View style={styles.caseItem} >
<Card style={styles.card}>
<CardItem>
<Body>
<View style={styles.rowTitle}>
<Text style={styles.title}>{item.FullName}</Text>
<Menu
ref={this.setMenuRef}
button={
<Icon
type="Feather"
name="more-vertical"
onPress={this.showMenu}
style{{fontSize:20,color:'#555'}}
/>
}>
<MenuItem onPress={this.hideMenu}>View</MenuItem>
<MenuItem onPress={this.hideMenu}>Edit</MenuItem>
<MenuItem onPress={this.hideMenu}>Delete </MenuItem>
</Menu>
</View>
<View>
<Text style={styles.lbl}>Email: <Text style={styles.lblValue}>{item.EmailID}</Text></Text>
<Text style={styles.lbl}>Client Type: <Text style={styles.lblValue}>{item.ClientType}</Text></Text>
</View>
</Body>
</CardItem>
</Card>
</View>
);
}}
keyExtractor={item => item.ID}
/>
Snack Here
To handle the states in the correct way, you will need to create a new Class which will be handling just the MenuItem
The below code will work: Here is the Snack.
import * as React from "react";
import { Text, View, StyleSheet } from "react-native";
import Constants from "expo-constants";
import { Container, Content, Card, CardItem, Body, Icon } from "native-base";
import * as Font from "expo-font";
import Menu, { MenuItem, MenuDivider } from "react-native-material-menu";
// You can import from local files
import AssetExample from "./components/AssetExample";
export default class App extends React.Component {
onView = () => {
alert("Do something here");
console.log("You can do what ever you want here");
}
render() {
return (
<View style={styles.container}>
<View style={styles.caseItem}>
<Card style={styles.card}>
<CardItem>
<Body>
<View style={styles.rowTitle}>
<Text style={styles.title}>John Doe</Text>
<CustomMenu onView={this.onView}/>
</View>
<View>
<Text style={styles.lbl}>
Email: <Text style={styles.lblValue}>john#yopmail.com</Text>
</Text>
<Text style={styles.lbl}>
Client Type: <Text style={styles.lblValue}>Individual</Text>
</Text>
</View>
</Body>
</CardItem>
</Card>
</View>
<View style={styles.caseItem}>
<Card style={styles.card}>
<CardItem>
<Body>
<View style={styles.rowTitle}>
<Text style={styles.title}>John Doe</Text>
<CustomMenu onView={this.onView}/>
</View>
<View>
<Text style={styles.lbl}>
Email: <Text style={styles.lblValue}>john#yopmail.com</Text>
</Text>
<Text style={styles.lbl}>
Client Type: <Text style={styles.lblValue}>Individual</Text>
</Text>
</View>
</Body>
</CardItem>
</Card>
</View>
<View style={styles.caseItem}>
<Card style={styles.card}>
<CardItem>
<Body>
<View style={styles.rowTitle}>
<Text style={styles.title}>John Doe</Text>
<CustomMenu onView={this.onView} />
</View>
<View>
<Text style={styles.lbl}>
Email: <Text style={styles.lblValue}>john#yopmail.com</Text>
</Text>
<Text style={styles.lbl}>
Client Type: <Text style={styles.lblValue}>Individual</Text>
</Text>
</View>
</Body>
</CardItem>
</Card>
</View>
</View>
);
}
}
class CustomMenu extends React.Component {
_menu = null;
setMenuRef = ref => {
this._menu = ref;
};
hideMenu = () => {
this._menu.hide();
};
onViewClick = () => {
const {onView} = this.props;
onView();
this.hideMenu();
}
showMenu = () => {
this._menu.show();
};
render() {
return (
<Menu
ref={this.setMenuRef}
button={
<Icon
type="Feather"
name="more-vertical"
onPress={this.showMenu}
style={{ fontSize: 20, color: "#555" }}
/>
}
>
<MenuItem onPress={this.onViewClick}>View</MenuItem>
<MenuItem onPress={this.hideMenu}>Edit</MenuItem>
<MenuItem onPress={this.hideMenu}>Delete </MenuItem>
</Menu>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: "center",
paddingTop: Constants.statusBarHeight,
backgroundColor: "#ecf0f1",
padding: 8
},
rowTitle: {
flexDirection: "row",
justifyContent: "space-between",
width: "100%"
},
title: {
fontSize: 14,
marginBottom: 5
},
lbl: {
fontSize: 11,
color: "#000"
},
lblValue: {
fontSize: 11,
color: "#555",
fontWeight: "normal"
},
caseItem: {
marginBottom: 0
}
});
Since the FlatList will iterate over the menu items, you need to maintain index for each iterable menu options.
You can check, you are passing item object within renderItems prop. So you can use the same item.id as a key to your child (iterable) component.
Since the child component now maintains an index, so now you can pass it in methods which will help you differentiate the event which got triggered from the child element.
I hope this might give you an idea about the issue.

Not able to access the absolute position view in react-native android

I have a component called MDropDowlList which render the following view :
MDropDownList.js
render() {
return (
<View>
<View
style={{
backgroundColor: '#fff',
position: 'absolute',
left: 0,
right: 0,
top: 0,
maxHeight: 200,
}}
>
{
this.props.searchable && (
<TextInput
style={{ zIndex: 198 }}
onChangeText={(text) => this.search(text)}
/>
)
}
<FlatList
data={this.state.data}
keyboardShouldPersistTaps="always"
nestedScrollEnabled={true}
contentContainerStyle={{ zIndex: 199 }}
keyExtractor={(item, index) => index.toString()}
renderItem={({ item, index }) => (
<TouchableHighlight
key={index.toString()}
style={{
padding: 10,
backgroundColor: '#fff',
}}
underlayColor="#5897fb"
onPress={() => this.props.handleOnPress(item)}
>
<MText size={18}>{item}</MText>
</TouchableHighlight>
)}
/>
</View>
</View>
);
}
Then I have called this component to another component called MDropDown which render method is as below :
MDropDown.js
render() {
return (
<View style={{ marginVertical: 5, zIndex: 3}}>
...
{/* Another components */}
...
{
this.state.displayDropDown && (
<MDropDownList data={this.props.data} searchable={this.props.searchable} handleOnPress={(item) => this.handleOnPress(item)} />
)
}
</View>
);
}
Now finally I called my MDropDown component in my main screen as follow :
render() {
return (
<KeyboardAvoidingView style={{ flex: 1, backgroundColor: Colors.bgGray }} behavior="padding">
<ScrollView showsVerticalScrollIndicator={false} contentContainerStyle={styles.container} keyboardShouldPersistTaps="always" nestedScrollEnabled={true}>
<View style={{ backgroundColor: '#fff', padding: 10 }}>
<MDropDown
label="Category"
placeholder="Select Category"
data={["test1", "test2", "test3", "test4", "test5"]}
onSelectItem={(selectedItem) => alert(selectedItem)}
searchable={true}
/>
</View>
</ScrollView>
</KeyboardAvoidingView>
)
}
But I am not able to access Flatlist item or TextInput of MDropDownList component. Even I am not able to focus TextInput available in MDropDownList.
Please help me what's going wrong here ???
Note : This issue is only on android, on ios it is working properly. On ios I am able to click flatlist item and focus TextInput as well as.
Tried using zIndex to the absolute view?
Add property of zIndex : 500 to the style.

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