Can't find variable: StyleSheet - javascript

I'm studying React Native with this site https://www.tutorialspoint.com/react_native/react_native_animations.htm
However, there is a problem while i'm trying to open app on iPhone. According to error it cannot find variable, though it's imported.
import React, { Component } from 'react';
import { View, LayoutAnimation, TouchableOpacity, Text, StyleSheet} from 'react-native';
export default class Animations extends Component {
state = {
myStyle: {
height: 100,
backgroundColor: 'red'
}
};
expandElement = () => {
LayoutAnimation.configureNext(LayoutAnimation.Presets.spring);
this.setState({
myStyle: {
height: 400,
backgroundColor: 'red'
}
})
};
collapseElement = () => {
LayoutAnimation.configureNext(LayoutAnimation.Presets.linear);
this.setState({
myStyle: {
height: 100,
backgroundColor: 'red'
}
})
};
render() {
return (
<View>
<View>
<View style={this.state.myStyle}/>
</View>
<TouchableOpacity>
<Text style={styles.button} onPress = {this.expandElement}>
Expand
</Text>
</TouchableOpacity>
<TouchableOpacity>
<Text style={styles.button} onPress = {this.collapseElement}>
Collapse
</Text>
</TouchableOpacity>
</View>
)
}
}
const styles = StyleSheet.create({
button: {
borderWidth: 1,
borderColor: 'red',
color: 'red',
textAlign: 'center',
marginTop: 50,
padding: 10
}
});

Ah... I've found the problem. It was in other component which had styles but no elements to them and had no imported StylesSheet since I corrected it to new conditions but forgot about block with styles.

Related

React Native change background color on container view doesn't work

I am new to react native. I tried to change the background view on the container seems like it doesn't work. I attached the codes below.
Could anyone here tell me what is wrong with the code below?
const HomeScreen = () => {
return (
<SafeAreaView style={{ flex: 1 }}>
<View style={{ flex: 1, backgroundColor: '#FF0000' }}>
<Text style={{
color: COLORS.Text,
marginLeft: 14,
marginTop: 16,
width: 100,
height: 20
}}>Hello world</Text>
</View>
</SafeAreaView>
);
Check the below code:
import React from 'react';
import {StyleSheet, Text, SafeAreaView } from 'react-native';
const App = () => {
return (
<SafeAreaView style={styles.container}>
<Text style={styles.text}>Page content</Text>
</SafeAreaView>
);
};
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor:'green'
},
text: {
fontSize: 25,
fontWeight: '500',
},
});
export default App;
For more information, you can explore SafeArea Documentation.

Function inside Text Tag React Native

I am having an issue with the react-native Text tag. I could not figure out why this happening. Please, help out.
I need to use the function retrieveData inside the Text tag but that gives an error. What am I doing wrong? Thanks
I have set the data(mobileNumber as key) using AsyncStorage inside another file.
import React, { Component } from "react";
import {
View,
Text,
TextInput,
SafeAreaView,
TouchableOpacity,
AsyncStorage
} from "react-native";
export default class PhoneCode extends Component {
constructor(props) {
super(props);
this.state = {
};
}
onVerify = () => {};
onPress = () => {
alert("Sending...");
};
tappedVerify = () => {
console.log("clicked")
};
render() {
const { code, isCodeValid } = this.state;
const _retrieveData = async () => {
try {
const value = await AsyncStorage.getItem("mobileNumber");
if (value !== null) {
// We have data!!
return value;
}
} catch (error) {
// Error retrieving data
console.log("failed");
}
};
return (
<SafeAreaView style={styles.container}>
<View style={styles.contentArea}>
<Text style={{}}> Enter... </Text>
<View style={styles.codeArea}>
<Text style={styles.codeInput}> {_retrieveData()} </Text> // this is the problem
<TextInput
placeholder="Enter here"
underlineColorAndroid="transparent"
style={styles.textInput}
maxLength={6}
autoGrow={true}
maxHeight={40}
keyboardType={"phone-pad"}
onChangeText={(text) =>
this.setState({
//....
})
}
/>
</View>
</View>
</SafeAreaView>
Here is the style object
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: "flex-start",
alignItems: "center"
},
contentArea: {
justifyContent: "flex-start",
alignItems: "center",
width: '100%',
height: '100%',
paddingTop: 80,
paddingLeft: 20,
paddingRight: 20
},
textInput: {
textAlign: 'center',
height: 50,
width: '18%',
borderWidth: 2,
borderColor: 'gray',
borderRadius: 20,
backgroundColor: "#FFFFFF"
}
})
Here is the error message
ExceptionsManager.js:74 Invariant Violation: Objects are not valid as a React child (found: object with keys {_40, _65, _55, _72}). If you meant to render a collection of children, use an array instead.
Doing this solves my problem. It might help someone else.
<Text style={styles.codeInput}> {`${_retrieveData()}`} </Text>

How to render a partial view on another view in react native

When I tried alert("Hi") in renderMoreView function, it actually works, but to display the View is the problem I am facing
export default class Home extends Component {
state = {
moreButton: false,
};
renderMoreView = () => {
return (
<View style={{flex: 1, height: 50, width: 50}}>
<Text>Hi</Text>
</View>
);
};
render () {
return (
<View>
.....
<TouchableOpacity
underlayColor="transparent"
onPress={() => this.setState ({moreButton: true})}
>
<Feather name="more-vertical" size={25} />
</TouchableOpacity>
...
{this.state.moreButton ? this.renderMoreView () : null}
</View>
);
}
}
This is what I am trying to do]
If I understand your question right, you could use Modal component. https://facebook.github.io/react-native/docs/modal
This can be done using modal. But if you want to do it more simply, install and use the module. react-native-awesome-alerts
$ npm i react-native-awesome-alerts --save
Example
import React from 'react';
import { StyleSheet, View, Text, TouchableOpacity } from 'react-native';
import AwesomeAlert from 'react-native-awesome-alerts';
export default class App extends React.Component {
constructor(props) {
super(props);
this.state = { showAlert: false };
};
showAlert = () => {
this.setState({
showAlert: true
});
};
hideAlert = () => {
this.setState({
showAlert: false
});
};
render() {
const {showAlert} = this.state;
return (
<View style={styles.container}>
<Text>I'm AwesomeAlert</Text>
<TouchableOpacity onPress={() => {
this.showAlert();
}}>
<View style={styles.button}>
<Text style={styles.text}>Try me!</Text>
</View>
</TouchableOpacity>
<AwesomeAlert
show={showAlert}
showProgress={false}
title="AwesomeAlert"
message="I have a message for you!"
closeOnTouchOutside={true}
closeOnHardwareBackPress={false}
showCancelButton={true}
showConfirmButton={true}
cancelText="No, cancel"
confirmText="Yes, delete it"
confirmButtonColor="#DD6B55"
onCancelPressed={() => {
this.hideAlert();
}}
onConfirmPressed={() => {
this.hideAlert();
}}
/>
</View>
);
};
};
const styles = StyleSheet.create({
container: {
flex: 1,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: '#fff',
},
button: {
margin: 10,
paddingHorizontal: 10,
paddingVertical: 7,
borderRadius: 5,
backgroundColor: "#AEDEF4",
},
text: {
color: '#fff',
fontSize: 15
}
});

React Native Text color not working

I've got a Text component inside a TouchableOpacity which I want to change the color depend on a var.
Here is my code:
import React, { Component } from "react";
import { StyleSheet, Text, View, TouchableOpacity } from "react-native";
var flag = false;
export default class MyTest extends Component {
changeColor() {
flag = true;
}
render() {
return (
<View style={styles.container}>
<TouchableOpacity
style={{ flex: 1, backgroundColor: "#888888", margin: 20 }}
onPress={this.changeColor.bind(this)}
>
<Text style={[{ color: "blue" }, flag ? { color: "red" } : false]}>
One
</Text>
</TouchableOpacity>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: "center",
backgroundColor: "#F5FCFF"
}
});
I have tried to use this.state.textColor but no result. I've also tried to use that in styles variable but again, not working.
Any idea?
The flag variable is not in your component state, so the component will not re-render when it changes.
Put it in your component state instead and toggle it with setState and it will work.
class MyTest extends Component {
state = { flag: true };
changeColor = () => {
this.setState(previousState => {
return { flag: !previousState.flag };
});
};
render() {
return (
<View style={styles.container}>
<TouchableOpacity
style={{ flex: 1, backgroundColor: "#888888", margin: 20 }}
onPress={this.changeColor}
>
<Text style={{ color: this.state.flag ? "red" : "blue" }}>One</Text>
</TouchableOpacity>
</View>
);
}
}
You have to give style to the Text for color.
<Text style={styles.steelblue}>Sign Up</Text>
Give this style to Text.
const styles = StyleSheet.create({
steelblue: {
color: "steelblue",
},
});
try this example this may help you to solve problem.
import React, { Component } from 'react';
import { Platform, StyleSheet, View, Text } from 'react-native';
export default class App extends Component {
render() {
return (
<View style={styles.container}>
<Text style={[styles.setFontSize,styles.setColorRed]}> React Native Font example 1</Text>
<Text style={[styles.setFontSize,styles.setColorPink]}> React Native Font example 2</Text>
<Text style={[styles.setFontSize,styles.setColorPurple]}> React Native Font example 3</Text>
<Text style={[styles.setFontSize,styles.setColorBlue]}> React Native Font example 4</Text>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center'
},
setFontSize: {
fontSize: 20,
fontWeight : 'bold'
},
setColorRed : {
color: '#f44336'
},
setColorPink :{
color: '#e91e63'
},
setColorPurple :{
color: '#9c27b0'
},
setColorBlue :{
color: '#2196f3'
},
});

React Native - unexpected rendering of component

I am rendering a ListView in a React Native app that I'm building and am finding that a parent View container for the row is not expanding to fit all the content within it and I'm not sure why.
See in screenshot below how the second row within the row is rendered within the margin of the row view:
Component is as follows:
import React from 'react';
import { connect } from 'react-redux';
import {
View,
Text
} from 'react-native';
import { Icon } from 'native-base';
const ListViewRow = (props) => {
const { booking } = props;
const guest = props.guests[booking.guest_id];
return (
<View style={styles.rowStyle}>
<View style={styles.leftContentStyle}>
<View>
<Text>{guest.fullname}</Text>
</View>
<View>
<Text>{booking.start_date} - {booking.end_date}</Text>
</View>
</View>
<View style={styles.rightContentStyle}>
<Icon name='ios-arrow-forward' />
</View>
</View>
);
};
const styles = {
rowStyle: {
flex: 1,
borderBottomWidth: 1,
padding: 10,
backgroundColor: '#fff',
justifyContent: 'space-between',
flexDirection: 'row',
borderColor: '#ddd',
position: 'relative'
},
leftContentStyle: {
alignItems: 'stretch'
},
rightContentStyle: {
flexDirection: 'row',
alignItems: 'center'
}
};
const mapStateToProps = state => {
return { guests: state.guests };
};
export default connect(mapStateToProps)(ListViewRow);

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