Develop Reference

TextBox above Keyboard

I am new to React Native and I have encountered a problem: my TextBox doesn't stay above the keyboard while I am writing in it.
These are the visuals from the application
Screenshot
And this is my Signup.js:
import React, { Component } from 'react';
import {
StyleSheet,
Text,
View,
TouchableOpacity
} from 'react-native';
import Form from '../components/Form';
import Logo2 from'../components/Logo2';
import {Actions} from 'react-native-router-flux';
export default class Signup extends Component {
goBack() {
Actions.pop()
}
render() {
return(
<View style={styles.container}>
<Logo2/>
<Form type="Registrar"/>
<View style={styles.signupTextCont}>
<Text style={styles.signupText}>Ja tens uma conta? </Text>
<TouchableOpacity onPress={this.goBack}><Text style={styles.signupButton}>Entra</Text></TouchableOpacity>
</View>
</View>
)
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#232122'
},
signupTextCont: {
flexGrow: 1,
justifyContent: 'center',
alignItems: 'flex-end',
paddingVertical: 16,
flexDirection: 'row'
},
signupText: {
color: 'rgba(255,255,255,0.7)',
fontSize:16
},
signupButton: {
color: '#FFA200',
fontSize:16,
fontWeight: '500'
}
});
I don't know what I need to code.
Could you please help me?

To replicate my comment that resolved your problem; you can use the component KeyboardAvoidingView from the package react-native. It levels up the area it contains above your virtual keyboard.
Wrap your code like this:
<KeyboardAvoidingView behavior={'position'} enabled>
<View style={styles.signupTextCont}>
<Text style={styles.signupText}>Ja tens uma conta? </Text>
<TouchableOpacity onPress={this.goBack}>
<Text style={styles.signupButton}>Entra</Text>
</TouchableOpacity>
</View>
</KeyboardAvoidingView>
Here's some more info about how it works: https://facebook.github.io/react-native/docs/keyboardavoidingview.

You can wrap your code with KeyboardAvoidingView rather than a normal View so that it can actually lift up any items inside it above the keyboard. You can use <KeyboardAvoidingView behavior="padding">
Hope it helps.

How to apply expo react-native custom font to the entire container

I tried to load a custom font for my react-native app that i'm developing with expo but i don't know how to load a font in a simplier way for the whole screen container.
Currently i used the offical expo doc: Expo Custom Font Documentation
They said to use a Font.loadAsync() function and then use the
this.state.fontLoaded? like this:
<View style={{ flex: 1, justifyContent: 'center', alignItems: 'center' }}>
{
this.state.fontLoaded ? (
<Text style={{ fontFamily: 'open-sans-bold', fontSize: 56 }}>
Hello, world!
</Text>
) : null
}
</View>
but did it exist a solution for applying the font on a container for example? I think it's not easy to e forced to surround EACH Text elements with the same function...
Currently the font is loading on ONE text element, but i would like to be able to easily use my font on a container, or many Text elements at once.
Here is my code:
state = {
fontLoaded: false,
};
async componentDidMount() {
await Font.loadAsync({
'ubuntu-medium': require('../assets/fonts/Ubuntu-Medium.ttf'),
});
this.setState({ fontLoaded: true });
}
render() {
return (
<View style={styles.main_container}>
<View style={styles.inner_main_container}>
<View style={styles.top_links_container}>
<View style={styles.profile_and_arrow_container}>
<Icon
name='arrow-back'
color='white'
style={styles.icon} />
{
this.state.fontLoaded ? (
<Text style={styles.top_links_profile}>Profil</Text>
) : null
}
</View>
<View style={styles.profile_edit_container}>
<Text style={styles.top_links_edit}>Editer</Text>
</View>
</View>
<View style={styles.profile_avatar_container}>
<Avatar
rounded
size='xlarge'
source={{ uri: 'https://randomuser.me/api/portraits/men/27.jpg' }}>
</Avatar>
</View>
<View style={styles.profile_infos_container}>
{
this.state.fontLoaded ? (
<Text style={styles.user_name}> Dupont Jean </Text>
) : null
}
<Text style={styles.user_title}> CSD - Product Owner </Text>
</View>
<View style={styles.subprofile_infos_container}>
<View style={styles.user_experience}>
<Text>Experience </Text>
<Text style={styles.user_experience_years}> 7ans</Text>
</View>
<View style={styles.user_grade}>
<Text>Grade </Text>
<Text style={styles.user_grade_letter}> D </Text>
</View>
</View>
<View numberOfLines={6}>
<Text style={styles.user_bio}> Lorem Ipsum is simply dummy text of the printing and
typesetting industry. Lorem Ipsum has been the industry's standard…</Text>
</View>
<View>
<Text style={styles.user_bio_see_more_link}> Voir plus</Text>
</View>
<Divider style={styles.divider} />
<View style={styles.bottom_container}>
<View style={styles.bottom_cm_text_info_container}>
<Text style={styles.bottom_cm_text_info}>Carrière Manager d'Evelyne</Text>
<Text style={styles.bottom_cm_text_user_name}>Jerôme Durand</Text>
</View>
<View style={styles.bottom_cm_avatar}>
<Avatar
rounded
size='small'
source={{ uri: 'https://randomuser.me/api/portraits/men/27.jpg' }}
/>
<Icon
name='right'
type='antdesign'
color='grey'
onPress={() => console.log('hello button cm view')}
/>
</View>
</View>
</View>
</View>
);
}
}

Finally i found a nicely working solution.
I had to create a custom component like this one:
1. Create a custom component TextCustom.js for example and put this into:
import React from 'react'
import { Text, StyleSheet, View, ActivityIndicator } from 'react-native'
import * as Font from 'expo-font'
export default class TextCustom extends React.Component {
constructor(props) {
super(props)
this.state = {
loading: true,
}
}
async componentWillMount() {
await Font.loadAsync({
'Ubuntu': require('./../assets/fonts/Ubuntu-Medium.ttf')
})
this.setState({ loading: false })
}
render() {
if (this.state.loading) {
return <ActivityIndicator/>
}
return (
<View>
<Text style={[styles.defaultStyle, this.props.style]}>
{this.props.children}
</Text>
</View>
)
}
}
const styles = StyleSheet.create({
defaultStyle: {
fontFamily: 'Ubuntu'
},
})
Don't forget to import Font from Expo (for people using Expo)
2. in the component you want to use the custom font, simply import and use the newly created component:
import TextCustom from './TextCustom'
import TextBoldCustom from './TextBoldCustom' (if you want to use a Bold or italic font)
and use it:
<View>
<TextCustom style={styles.info_welcome}>Bonjour</TextCustom>
</View>

The documentation says there is no way to set the font across the entire app.
The recommended way to use consistent fonts and sizes across your application is to create a component MyAppText that includes them and use this component across your app. You can also use this component to make more specific components like MyAppHeaderText for other kinds of text.
More info and example on the Expo <Text> docs:
https://docs.expo.io/versions/latest/react-native/text/
--
As far as loading custom font files, I'd recommend using SplashScreen.preventAutoHide() to keep the splash screen visible while you load the fonts in a function via <AppLoading>. This provides a smooth loading experience, and ensures your fonts are available when the rest of your app is eventually rendered.

How to make <Text /> as watermark of images in React Native

To make <Text /> as watermark of images, it shows in official Docs:
Background Image via Nesting
A common feature request from developers familiar with the web is background-image. To handle this use case, simply create a normal <Image> component and add whatever children to it you would like to layer on top of it.
return (
<Image source={...}>
<Text>Inside</Text>
</Image>
);
I tried, the "Inside" has white background, not the part of the image.
How to make "Inside" as a watermark of the image? Thanks.

You can use ImageBackground component
Link-> https://reactnative.dev/docs/imagebackground
import React from "react";
import { ImageBackground, StyleSheet, Text, View } from "react-native";
const image = { uri: "https://reactjs.org/logo-og.png" };
const App = () => (
<View style={styles.container}>
<ImageBackground source={image} resizeMode="cover" style={styles.image}>
<Text style={styles.text}>Inside</Text>
</ImageBackground>
</View>
);
const styles = StyleSheet.create({
container: {
flex: 1,
},
image: {
flex: 1,
justifyContent: "center"
},
text: {
color: "white",
fontSize: 42,
lineHeight: 84,
fontWeight: "bold",
textAlign: "center",
backgroundColor: "#000000c0"
}
});
export default App;

React Native Overlay Test Error:

I hope all is well! First off, I'd like to thank you for being such a great developers and supporter of the SO community - you really make a difference!
I wanted to ask you about how to solve an error I continue to encounter when using react-native-overlay.
It seems when I put the overlay tags within a touchable highlight in order to bring the nested text to the forefront of the view - I get the following error:
Invariant Violation: Touchable child must either be native or forward setNativeProps to a native component. I have tried adding a native method within the class and that did not work (posted on another topic).
Any help would be greatly appreciated!
Here's my code so far:
/**
* Sample React Native App
* https://github.com/facebook/react-native
*/
'use strict';
var React = require('react-native');
var Overlay = require('react-native-overlay');
var {
Text,
View,
StyleSheet,
Image,
TouchableHighlight,
AppRegistry
} = React;
var styles = StyleSheet.create({
container: {
marginTop: 0,
flex: 1
},
buttonText: {
fontSize: 24,
color: 'white',
alignSelf: 'center',
},
bgImage: {
flex: 1,
flexDirection: 'row',
justifyContent: 'center',
alignItems: 'stretch',
resizeMode: 'cover',
},
});
class App extends React.Component{
makeBackground(btn){
var obj = {
flexDirection: 'row',
alignSelf: 'stretch',
justifyContent: 'center',
flex: 1,
backgroundColor: "#020202",
opacity: 0.3,
}
return obj;
}
goToProfile(){
console.log('Going to Profile');
}
goToRepos(){
console.log('Going to Repos');
}
goToNotes(){
console.log('Going to Notes');
}
render(){
return (
<View style={styles.container}>
<Image source={{uri: 'http://s3.amazonaws.com/rapgenius/1365796760_TommieSmithAP276.jpg'}} style={styles.bgImage} >
<TouchableHighlight
style={this.makeBackground(0)}
onPress={this.goToProfile.bind(this)}
underlayColor="#88D4F5">
<Overlay>
<Text style={styles.buttonText}>Causes</Text>
</Overlay>
</TouchableHighlight>
</Image>
<Image source={{uri: 'http://a57.foxnews.com/global.fncstatic.com/static/managed/assets/876/493/baltimore%20suspect%20injured.jpg?ve=1&tl=1'}} style={styles.bgImage}>
<TouchableHighlight
style={this.makeBackground(1)}
onPress={this.goToRepos.bind(this)}
underlayColor="#E39EBF">
<Text style={styles.buttonText}>News</Text>
</TouchableHighlight>
</Image>
<Image source={{uri: 'http://cdn.breitbart.com/mediaserver/Breitbart/Big-Government/2014/08/16/ferguson-rioter-tear-gas-AP.jpg'}} style={styles.bgImage}>
<TouchableHighlight
style={this.makeBackground(2)}
onPress={this.goToNotes.bind(this)}
underlayColor="#9BAAF3">
<Text style={styles.buttonText}>Hashtags</Text>
</TouchableHighlight>
</Image>
<Image source={{uri: 'http://www.swurvradio.com/wp-content/uploads/2015/06/Jason-Derulo-Ciara-and-Tinashe-honor-Janet-Jackson-with-a-dance-medley-at-the-BET-Awards-on-June-28-2015-in-Los-Angeles..jpg'}} style={styles.bgImage}>
<TouchableHighlight
style={this.makeBackground(3)}
onPress={this.goToNotes.bind(this)}
underlayColor="#9BAAF3">
<Text style={styles.buttonText}>Entertainment</Text>
</TouchableHighlight>
</Image>
</View>
)
}
};
AppRegistry.registerComponent('App', () => App);
The error I get is the following:
Error: Invariant Violation: Touchable child must either be native or forward setNativeProps to a native component
stack:
ensureComponentIsNative index.ios.bundle:35696
React.createClass.componentDidMount index.ios.bundle:35353
CallbackQueue.assign.notifyAll index.ios.bundle:5332
ReactNativeReconcileTransaction.ON_DOM_READY_QUEUEING.close index.ios.bundle:16113
ReactNativeReconcileTransaction.Mixin.closeAll index.ios.bundle:6636
ReactNativeReconcileTransaction.Mixin.perform index.ios.bundle:6577
batchedMountComponentIntoNode index.ios.bundle:8012
Object.ReactDefaultBatchingStrategy.batchedUpdates index.ios.bundle:15893
Object.batchedUpdates index.ios.bundle:5095
URL: undefined
line: undefined
message: Invariant Violation: Touchable child must either be native or forward setNativeProps to a native componenthandleException # ExceptionsManager.js:62

All Touchable has only one child and it should be native (View, Text, Image etc).

How to add a button in React Native?

I´m confused with this whole "no CSS" thing, but I understand why it's beneficial. All I want to do is place a button in the middle of the screen but I don't understand how styling works in React yet. This is my code:
var tapSpeed = React.createClass({
render: function() {
return (
<View style={styles.container}>
<Text style={styles.welcome}>
Tap me as fast as you can!
</Text>
<View style={styles.button}>
!
</View>
</View>
);
}
});
var styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#FFCCCC'
},
welcome: {
fontSize: 20,
textAlign: 'center',
margin: 10
},
button: {
textAlign: 'center',
color: '#ffffff',
marginBottom: 7,
border: 1px solid blue,
borderRadius: 2px
}
});

Update: use built-in Button component.
Deprecated:
Wrap your View into TouchableHighlight for iOS and TouchableNativeFeedback for Android.
var {
Platform,
TouchableHighlight,
TouchableNativeFeedback
} = React;
var tapSpeed = React.createClass({
buttonClicked: function() {
console.log('button clicked');
},
render: function() {
var TouchableElement = TouchableHighlight;
if (Platform.OS === 'android') {
TouchableElement = TouchableNativeFeedback;
}
return (
<View style={styles.container}>
<Text style={styles.welcome}>
Tap me as fast as you can!
</Text>
<TouchableElement
style={styles.button}
onPress={this.buttonClicked.bind(this)}>
<View>
<Text style={styles.buttonText}>Button!</Text>
</View>
</TouchableElement>
</View>
);
}
});

You can use built in react-native Button element.
import React, { Component } from 'react';
import { StyleSheet, View, Button, Alert, AppRegistry } from 'react-native';
class MainApp extends Component {
_onPress() {
Alert.alert('on Press!');
}
render() {
return (
<View style={styles.container}>
<View style={styles.buttonContainer}>
<Button onPress={this._onPress} title="Hello" color="#FFFFFF" accessibilityLabel="Tap on Me"/>
</View>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#FFFFFF'
},
buttonContainer: {
backgroundColor: '#2E9298',
borderRadius: 10,
padding: 10,
shadowColor: '#000000',
shadowOffset: {
width: 0,
height: 3
},
shadowRadius: 10,
shadowOpacity: 0.25
}
})
AppRegistry.registerComponent('MainApp', () => MainApp);
Read More Here.

The react-native-button package provides a button that is styled like a native button. Install it with npm install react-native-button and use it in your component like this:
var Button = require('react-native-button');
var ExampleComponent = React.createClass({
render() {
return (
<Button
style={{borderWidth: 1, borderColor: 'blue'}}
onPress={this._handlePress}>
Press Me!
</Button>
);
},
_handlePress(event) {
console.log('Pressed!');
},
});

You have two options to achieve a touchable component/button to handle user's events.
One is to use the built in Button Component. Check the docs here http://facebook.github.io/react-native/docs/button.html
Two use either TouchableHighlight or TouchableNativeFeedback or TouchableOpacity or TouchableWithoutFeedback. Think of this as a way for you to convert different areas of your app to tappable(clickable) or a way for you to create a custom button.
Each component here is different based on how it behaves once it's tapped by the user. Check the docs for more details. http://facebook.github.io/react-native/docs/touchablewithoutfeedback.html etc.
Concerning styling in react native you will need to understand flexbox layout. Check this css flexbox article all rules are applicable to react-native https://css-tricks.com/snippets/css/a-guide-to-flexbox/ except that you will have to capitalize the rules e.g align-content to alignContent

<Button
onPress={onPressLearnMore}
title="Learn More"
color="#841584"
accessibilityLabel="Learn more about this purple button"
/>

Please check react-native doc's regarding the buttons
You have more than one way to add button in your application and styling it
You can use Button tag and it's have only one way styling by color attribute, it will appearing in IOS different than Android, or by putting button in view tag with style
<View style={style.buttonViewStyle}>
<Button title="Facebook" color="blue" onPress={this.onFacebookPress} />
</View>
And check the TouchableOpacity and TouchableNativeFeedback tags
And take a lock on below link for more options to add custom buttons in your app
https://js.coach/react-native/react-native-action-button?search=button

export default class Login extends React.Component {
barcodeAction = () => {
this.props.navigation.navigate('BarCodeScanner')
}
cleverTapAction = () => {
this.props.navigation.navigate('CleverTapApp')
}
}
render() {
return (
<View style={styles.container}>
<View style={styles.buttonContainer}>
<Button
onPress={this._onPressButton}
title="Press Me"
/>
</View>
<View style={styles.buttonContainer}>
<Button
onPress={this._onPressButton}
title="Press Me"
color="#841584"
/>
</View>
<View style={styles.alternativeLayoutButtonContainer}>
<Button
onPress={this._onPressButton}
title="This looks great!"
/>
<Button
onPress={this._onPressButton}
title="OK!"
color="#841584"
/>
</View>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
},
buttonContainer: {
margin: 20
},
alternativeLayoutButtonContainer: {
margin: 20,
flexDirection: 'row',
justifyContent: 'space-between'
}
});

The Button element from react-native package does not provide built in styling feature. Ex. The "title" props will be in upper case by default. Hence, I've used an another package react-native-elements that provides nice features for Button element along with different styling options.
You can refer more details on Button from react-native-elements

import React, { Component } from 'react';
import { StyleSheet, View, TouchableOpacity, Text} from 'react-native';
var tapSpeed = React.createClass({
render: function() {
return (
<View style={styles.container}>
<TouchableOpacity>
<Text style={styles.welcome}>
Tap me as fast as you can!
</Text>
</TouchableOpacity>
<TouchableOpacity style={styles.button}>
<Text>!</Text>
</TouchableOpacity>
</View>
);
}
});
var styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
flexDirection: 'column',
alignItems: 'center',
backgroundColor: '#FFCCCC'
},
welcome: {
fontSize: 20,
textAlign: 'center',
margin: 10,
alignSelf: 'center'
},
button: {
justifyContent: 'center',
alignItems: 'center',
marginBottom: 7,
border: 1px solid blue,
borderRadius: 2px
}
});