Develop Reference

React Native TextField component in external library on focus

I have a Register Component that has PhoneInput Component from the external library https://github.com/thegamenicorus/react-native-phone-input The problem is I want to execute some code as soon as TextField inside the PhoneInput is Focused.
While checking the documentation of the library. I saw a property called the textComponent. Can that be used for onFocus of the text field present in PhoneInput Component
import React from 'react';
import {Image, StyleSheet, Text, View} from 'react-native';
import PhoneInput from 'react-native-phone-input'
export default class Register extends React.Component {
constructor(props){
super(props);
this.state = {"phone": ""};
this.countriesList = [
{
"name": "India (भारत)",
"iso2": "in",
"dialCode": "91",
"priority": 0,
"areaCodes": null
}];
this.phoneTextField=null;
}
componentDidMount() {
console.log('GrandChild did mount.');
// console.log(this.phoneTextField);
}
render() {
console.log(this.phoneTextField);
console.log("Register Screen");
return (
<View style={{borderColor:'red', borderWidth:0, height:'100%' }}>
<View style={{borderColor:'green', borderWidth:0, height:'20%' }}>
<View style={{borderColor:'blue', borderWidth:0, resizeMode:'contain', width:'50%', height:'100%'}}>
<Image
style={{width: '100%', height: '100%' }}
source={ require("../assets/logo.png") }
/>
</View>
</View>
<View style={{borderColor:'green', borderWidth:0, height:'40%', marginLeft:'1%', marginTop:'5%' }}>
<View style={{borderColor:'blue', borderWidth:0, resizeMode:'contain', width:'100%', height:'100%'}}>
<Image
style={{width: '100%', height: '100%' }}
source={ require("../assets/welcomescreen.jpg") }
/>
</View>
</View>
<View style={{ margin : '7%'}}>
<Text style={{ fontSize:20, fontWeight:'bold' }}>Save your time</Text>
<Text style={{ fontSize:14, color:'grey', paddingTop:'5%' }}>Please Enter your mobile number to proceed</Text>
<PhoneInput ref={ref => {
this.phoneTextField = ref;
}}
style={{paddingTop:'10%'}}
countriesList={this.countriesList}
initialCountry='in'
onChangePhoneNumber={(phone)=>{
console.log(phone);
}}
/>
</View>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
alignItems: 'center',
justifyContent: 'center',
},
});
My App.js
import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
import Register from "./screens/Register";
export default class App extends React.Component {
render() {
console.log("hello bros");
return (
<Register/>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
alignItems: 'center',
justifyContent: 'center',
},
});

I'm not familiar with that library, however, textComponent accepts a function so you should be able to do this
textComponent={
()=>{
return(<TextInput
....some props here
onFocus={()=>console.log('focused')})
}}

Android Application Emulator keeps stopping on React Native

I was editing one of the '.js' files and after saving my work after some changes, when I typed 'rr' to refresh application on the emulator, I kept getting this message.
Android Application Emulator keeps stopping
App info
Close app
enter image description here
After creating Form.js and under a components folder in my project in the visual studio code editor and importing it in my Login.js that's where the error started to occur. IDK what I did wrong. I'm new to React Native and am just learning.
Form.js
import React, {Component} from 'react';
import {
StyleSheet,
Text,
View,
TextInput
} from 'react-native';
export default class Login extends Component<{}> {
render(){
return(
<View style={styles.container}>
<TextInput style={styles.inputBox}
underlineColorAndroid='rgba(0,0,0,0)'
placeholder="Email"
placeholderTextColor = "#ffffff"
/>
<TextInput style={styles.inputBox}
underlineColorAndroid='rgba(0,0,0,0)'
placeholder="Password"
placeholderTextColor = "#ffffff"
/>
</View>
)
}
}
const styles = StyleSheet.create({
container : {
flex: 1,
justifyContent: 'center',
alignItems: 'center'
},
inputBox: {
width:300,
backgroundColor:'rgba(255,255,255,0.3)',
borderRadius: 25,
paddingHorizontal: 16,
fontSize: 16,
color:'#ffffff',
marginVertical: '10'
}
});
Login.js
import React, {Component} from 'react';
import {
StyleSheet,
Text,
View,
StatusBar
} from 'react-native';
import Logo from '../components/Logo';
import Form from '../components/Form';
export default class Login extends Component<{}> {
render () {
return(
<View style={styles.container}>
<Logo/>
<Form/>
</View>
)
}
}
const styles = StyleSheet.create({
container : {
backgroundColor: '#29b6f6',
flex: 1,
alignItems: 'center',
justifyContent: 'center',
}
});

Here is your solution
Your application is crashed because of this props underlineColorAndroid="rgba(0,0,0,0)" in your TextInput and also minor change in inputBox style remove string value marginVertical: "10" to marginVertical: 10
Form.js
import React, { Component } from "react";
import { StyleSheet, Text, View, TextInput } from "react-native";
export default class Login extends Component {
render() {
return (
<View style={styles.container}>
<TextInput
style={styles.inputBox}
// underlineColorAndroid="rgba(0,0,0,0)"<---Comment this code---
placeholder="Email"
placeholderTextColor="#ffffff"
/>
<TextInput
style={styles.inputBox}
// underlineColorAndroid="rgba(0,0,0,0)"<---Comment this code---
placeholder="Password"
placeholderTextColor="#ffffff"
/>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: "center",
alignItems: "center"
},
inputBox: {
width: 300,
backgroundColor: "rgba(255,255,255,0.3)",
borderRadius: 25,
paddingHorizontal: 16,
fontSize: 16,
color: "#ffffff",
marginVertical: 10 <-----Remove string to number---
}
});
Output:--

createDrawerNavigator in react native

import React from 'react';
import { Text, View } from 'react-native';
import { createDrawerNavigator, createAppContainer } from 'react-navigation';
class HomeScreen extends React.Component {
render() {
return (
<View style={{ flex: 1, justifyContent: 'center', alignItems: 'center' }}>
<Text style={{ color: 'red', fontSize: 30 ,fontWeight: 'bold'}}>Home!</Text>
</View>
);
}
}
class SettingsScreen extends React.Component {
render() {
return (
<View style={{ flex: 1, justifyContent: 'center', alignItems: 'center' }}>
<Text style={{ color: 'green' , fontSize: 20 ,fontWeight: 'bold'}}>Settings!</Text>
</View>
);
}
}
const MyDrawerNavigator = createDrawerNavigator({
Home:{
screen: HomeScreen,
},
Settings: {
screen: SettingsScreen,
},
});
export default createAppContainer(MyDrawerNavigator);
I was making navigation drawer with react native with above code.The problem which i faced is that drawer is not visible to me.I tried my best to solve this problem but i couldn't.Whats wrong with my code ?

you're missing the DrawerNavigatorConfig as a second parameter. There you config how the drawer displays and you set the content component to display within the drawer. Check the docs here: https://reactnavigation.org/docs/en/drawer-navigator.html

Can't run custom component in React native

Need some help with React Native. Searched in Google, but didn't find any solution.
I have one project which works on android. Here code:
import React, { Component } from 'react';
import {
AppRegistry,
StyleSheet,
Text,
View
} from 'react-native';
export default class MyApp extends Component {
render() {
return (
<View style={styles.container}>
<Text style={styles.welcome}>
Welcome to React Native!
</Text>
<Text style={styles.instructions}>
To get started, edit index.android.js
</Text>
<Text style={styles.instructions}>
Double tap R on your keyboard to reload,{'\n'}
Shake or press menu button for dev menu
</Text>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#F5FCFF',
},
welcome: {
fontSize: 20,
textAlign: 'center',
margin: 10,
},
instructions: {
textAlign: 'center',
color: '#333333',
marginBottom: 5,
},
});
AppRegistry.registerComponent('MyApp', () => MyApp);
But when i try to add my own component it like this:
import React, { Component } from 'react';
import {
AppRegistry,
StyleSheet,
Text,
View
} from 'react-native';
import MainPage from "./app/components/MainPage/MainPage";
export default class MyApp extends Component {
render() {
return (
<View style={styles.container}>
<Text style={styles.welcome}>
Welcome to React Native!
</Text>
<Text style={styles.instructions}>
To get started, edit index.android.js
</Text>
<Text style={styles.instructions}>
Double tap R on your keyboard to reload,{'\n'}
Shake or press menu button for dev menu
</Text>
<MainPage/>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#F5FCFF',
},
welcome: {
fontSize: 20,
textAlign: 'center',
margin: 10,
},
instructions: {
textAlign: 'center',
color: '#333333',
marginBottom: 5,
},
});
AppRegistry.registerComponent('MyApp', () => MyApp);
i get error in emulator:
Can somebody help?
Code for component MainPage:
import React, {Component} from 'react';
import {AppRegistry, StyleSheet, View, Text} from 'react-native';
export default class MainPage extends Component {
render() {
return (
<View>
<Text style={styles.welcome}>
Welcome to React Native!
</Text>
</View>
);
}
}
MainPage.propTypes = {}
MainPage.defaultProps = {}
const styles = StyleSheet.create({
welcome: {
fontSize: 20,
textAlign: 'center',
margin: 10,
}
});
AppRegistry.registerComponent('MainPage', () => MainPage);

I find solution. It was because of file format. It should be .js and not .jsx. After this correction all works fine. I hope it will help someone

Open another screen in react-native

I have this screen in react native
import React, { Component } from 'react';
import { AppRegistry,TouchableOpacity, Text ,Button,Image,TextInput,PropTypes,StyleSheet,View,NavigatorIOS,TouchableHighlight} from 'react-native';
class LoginView extends Component {
render() {
return (
<View style={styles.container}>
<Text style={styles.title}>
HYGEX
</Text>
<View>
<TextInput
placeholder="Username"
style={styles.formInput}
/>
<TextInput
placeholder="Password"
secureTextEntry={true}
style={styles.formInput1}
/>
<TouchableHighlight style={styles.button}
onPress={() => this.move()}>
<Text style={styles.buttonText}>Login</Text>
</TouchableHighlight>
</View>
</View>
);
}
move() {
//what i can do here to go to Socrce screen ???
}
}
Something like login screen, now when I click into TouchableHighlight
I need to open this screen
'use strict';
import React, { Component } from 'react';
import { AppRegistry, ListView, Text, View } from 'react-native';
class HygexListView extends Component {
constructor(props) {
super(props);
const ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});
this.state = {
dataSource: ds.cloneWithRows([
'John', 'Joel', 'James', 'Jimmy', 'Jackson', 'Jillian', 'Julie', 'Devin'
])
};
}
render() {
return (
<View style={{flex: 1, paddingTop: 22}}>
<ListView
dataSource={this.state.dataSource}
renderRow={(rowData) => <Text>{rowData}</Text>}
/>
</View>
);
}
}
module.exports = HygexListView;
I tried to implement move method but I failed! Any idea why?
Does react-native have a method to change the screen when click into TouchableHighlight?

As others pointed out, you have to use an instance of Navigator to transition between screens. Maybe you can have a look at the example apps in the React Native repo. I also find this router package quite easy to set up, and it also includes an example app that you can use as a starting point.
Edit
As a simple example using react-native-router-flux, you can edit the Example.js file in the Example directory to look like this:
import React, {
Component,
} from 'react';
import {
StyleSheet,
Text,
View,
} from 'react-native';
import LoginView from './LoginView';
import HygexListView from './HygexListView';
import {
Scene,
Router,
Actions,
} from 'react-native-router-flux';
const styles = StyleSheet.create({
container: { flex: 1, backgroundColor: 'transparent', justifyContent: 'center',
alignItems: 'center',
},
tabBarStyle: {
backgroundColor: '#eee',
},
tabBarSelectedItemStyle: {
backgroundColor: '#ddd',
},
});
// define this based on the styles/dimensions you use
const getSceneStyle = (/* NavigationSceneRendererProps */ props, computedProps) => {
const style = {
flex: 1,
backgroundColor: '#fff',
shadowColor: null,
shadowOffset: null,
shadowOpacity: null,
shadowRadius: null,
};
if (computedProps.isActive) {
style.marginTop = computedProps.hideNavBar ? 0 : 64;
style.marginBottom = computedProps.hideTabBar ? 0 : 50;
}
return style;
};
class Example extends Component {
render() {
return (
<Router getSceneStyle={getSceneStyle}>
<Scene key="login" component={LoginView} initial={true}/>
<Scene key="hygex" component={HygexListView } />
</Router>
);
}
}
export default Example;
Then, in your component's move function, you have to do the following:
move(){
Actions.hygex(); // This will perform a slide transition, but you can customize it. Have a look at the docs for that.
I have not tested the code, so there might be some typos/missing imports/code, but it should give you an idea of what you have to do.
}

You have to implement a Navigator, which is roughly a component that manages all stuff related to screens, and header bar with back button and etc.
As you are a beginner, I suggest you to look at the docs on this link:
https://facebook.github.io/react-native/docs/navigator.html
Sorry for the short answer, I'm on my phone.
Good luck!

"use strict";
var React = require("react-native");
var {
Component,
StyleSheet,
Text,
TextInput,
TouchableHighlight,
View,
} = React;
var SecureView = require("./SecureView");
class LoginView extends Component {
constructor(props) {
super(props);
this.state = {
username: "",
password: ""
};
}
render() {
return (
<View style={styles.container}>
<Text style={styles.title}>
Sign In
</Text>
<View>
<TextInput
placeholder="Username"
onChange={(event) => this.setState({username: event.nativeEvent.text})}
style={styles.formInput}
value={this.state.username} />
<TextInput
placeholder="Password"
secureTextEntry={true}
onChange={(event) => this.setState({password: event.nativeEvent.text})}
style={styles.formInput}
value={this.state.password} />
<TouchableHighlight onPress={(this.onSubmitPressed.bind(this))} style={styles.button}>
<Text style={styles.buttonText}>Submit</Text>
</TouchableHighlight>
</View>
</View>
);
}
onSubmitPressed() {
this.props.navigator.push({
title: "Secure Page",
component: SecureView,
passProps: {username: this.state.username, password: this.state.password},
});
}
};
var styles = StyleSheet.create({
container: {
padding: 30,
marginTop: 65,
alignItems: "stretch"
},
title: {
fontSize: 18,
marginBottom: 10
},
formInput: {
height: 36,
padding: 10,
marginRight: 5,
marginBottom: 5,
marginTop: 5,
flex: 1,
fontSize: 18,
borderWidth: 1,
borderColor: "#555555",
borderRadius: 8,
color: "#555555"
},
button: {
height: 36,
flex: 1,
backgroundColor: "#555555",
borderColor: "#555555",
borderWidth: 1,
borderRadius: 8,
marginTop: 10,
justifyContent: "center"
},
buttonText: {
fontSize: 18,
color: "#ffffff",
alignSelf: "center"
},
});
module.exports = LoginView;

You have to use navigator. please read the documentation as mentioned below. and if you will need then i will share you my code.
Here is an example: NavigatorExample