React Native - Push one Screen To Another have issue - react-native

I used the 'StackNavigator', I have issue to push when navigation code write in button event. but its working fine if we directly code onPress event,
Import file.
import { StackNavigator } from "react-navigation";
import SignUpScreen from "./SignUp";
Push another is working :
render() {
console.disableYellowBox = true;
const { navigate } = this.props.navigation;
return (
<View style={styles.viewStyle}>
<TouchableHighlight style = {styles.buttonStart}
onPress={() => navigate("SignUpCompany")}>
<Image
source={require('./Images/hire.png')}
/>
</TouchableHighlight>
</View>
);
}
Push another via function is not working :
pushcode() {
console.log('call');
this.props.navigation.navigate('SignUp');
}
render() {
return (
<TouchableHighlight style = {styles.buttonStart}
onPress={this.pushcode}>
<Image
source={require('./Images/hire.png')}
/>
</TouchableHighlight>
);}
ERROR ON CLICK BUTTON :
Thanks. Please help me.

Look like you are using the push extra in this line
this.props.navigation.navigate.push('SignUp');
Try this will work for you
this.props.navigation.navigate('SignUp');
May be this can help you

I think you miss the function bind within constructor --- that's why you got undefined is not an object (evaluating 'this.props.navigation'). because this is undefined inside pushcode function scope.
add below into your constructor:
constructor(props) {
super(props);
this.pushcode = this.pushcode.bind(this);
...
}

Related

How to reparent a component in ReactNative?

In the below code, I expected the webView content to not change when the clicks are increased, but every time it loads, a new timestamp is displayed.
const webView = (
<WebView
source={{
uri:
'data:text/html,<html><script>document.write("<h1 style=\\"font-size:64px\\">"+Date.now()+"<h1>");</script>',
}}
/>
);
export default class App extends React.Component {
state = {
clicks: 0,
};
onClick = () => {
this.setState({ clicks: this.state.clicks + 1 });
};
render() {
return (
<View>
<Text onPress={this.onClick}>
Click Me: {this.state.clicks}
</Text>
{this.state.clicks % 2 === 0 ? webView : null}
{this.state.clicks % 2 === 1 ? webView : null}
</View>
);
}
}
Link to expo snack to check it on a device.
So far, I've read about reparenting in React on issues here, implementing using Portals, and also saw an issue on supporting reparenting in react native with no resolution.
So, how to reuse a component instance in across multiple screens with out creating a new instance of it in every screen?
Was hoping reparenting would be the answer, but can't find any implementations, so if reparenting is the answer to this, how to implement it myself?
The problem here is that on every state change your component will re-render webView object and will show the current date. I suggest that you change webView to a component and add a static key when you call WebViewComp to prevent unmount/mount on every state change.
const WebViewComp = () => ( //Change declaration to function component instead of constant object
<WebView
source={{
uri:
'data:text/html,<html><script>document.write("<h1 style=\\"font-size:64px\\">"+Date.now()+"<h1>");</script>',
}}
/>
);
export default class App extends React.Component {
state = {
clicks: 0,
};
onClick = () => {
this.setState({ clicks: this.state.clicks + 1 });
};
render() {
return (
<View style={styles.container}>
<Text style={styles.paragraph} onPress={this.onClick}>
Click Me: {this.state.clicks}
</Text>
{this.state.clicks % 2 === 0 ? <WebViewComp key="child" /> : null}
{this.state.clicks % 2 === 1 ? <WebViewComp key="child" /> : null}
</View>
);
}
}
You definitely need to reparenting the view. I searched some libs that work as React Portals does.
We have two projects available:
https://github.com/zenyr/react-native-portal
https://github.com/mfrachet/rn-native-portals
I tested the second package (rn-native-portals) and this magically worked on Android:
How to install
npm install mfrachet/rn-native-portals
react-native link (unfortunately we can't auto-link this yet, but we can submit PR)
Implementation
Your target element needs to be inside <PortalOrigin>
import React from "react";
import { View, Text, TouchableOpacity } from "react-native";
import { PortalOrigin } from 'rn-native-portals';
class Target extends React.Component {
state = {
moveView: false,
}
render() {
return (
<>
<TouchableOpacity
style={{ flex: 1 }}
onPress={() => this.setState({ moveView: !this.state.moveView })}
>
<Text>Press Here</Text>
</TouchableOpacity>
<PortalOrigin destination={this.state.moveView ? 'destinationPortal' : null}>
<View>
<Text>This text will appear on destination magically...</Text>
</View>
</PortalOrigin>
</>
);
}
}
export default Target;
On destination use this (don't forget set the same unique portal's name)
import React from "react";
import { PortalDestination } from "rn-native-portals";
class Destination extends React.Component {
render() {
return (
<PortalDestination name="destinationPortal" />
);
}
}
export default Destination;
This project is amazing, but definitely need our community help to create a better documentation.
I have one project that need to use this feature, reparenting a video to the outside of screen. I'm seriously considering PR auto-link support to avoid compiling warnings.
More useful info about:
The project concept:
https://github.com/mfrachet/rn-native-portals/blob/master/docs/CONCEPT.md
Why the project was created (long history):
https://tech.bedrockstreaming.com/6play/how-a-fullscreen-video-mode-ended-up-implementing-react-native-portals/
Haven't tried the accepted answer's projects but, for React Native, #gorhom/portal works like a charm retaining context like a champ!

Null is not an object while creating navigation between screens in expo project

I need to open new screen after clicking on the button. For it I made the following steps:
1) Installed this library
2) Created a new screen and added it to the folder with other screens (DetailInfoScreen is a new screen, which should be opened and HomeScreen is a screen, where a button, after clicking on which new screen should be opened):
3) Added the following lines of code:
import { Navigation } from 'react-native-navigation';
import DetailInfoScreen from './DetailInfoScreen';
class HomeScreen extends Component {
constructor(props) {
super(props);
this.onPressSearch = this.onPressSearch.bind(this);
Navigation.registerComponent('DetailInfoScreen', () => DetailInfoScreen);
}
goToScreen = (screenName) => {
Navigation.push(this.props.componentId, {
component: {
name: screenName
}
});
}
render() {
const { list, text } = this.props;
return (
<View style={styles.container}>
<View style={styles.searchContainer}>
<TouchableOpacity
onPress={this.goToScreen('DetailInfoScreen')}
>
<View>
<Text>Search</Text>
</View>
</TouchableOpacity>
</View>
);
}
But when I run the project I have the following error:
And one more moment which disturbs me is that autocorrection in vscode doesn't see my new screen while importing:
Maybe it doesn't play any role, but still. So, what's the reason of the problem and how can I solve it?
You can simply navigate to another screen by using this:
<TouchableOpacity
onPress={() => this.props.navigation.navigate('DetailInfoScreen')>
<Text>Search</Text>
</TouchableOpacity>
I would personally advice for you to use react-navigation instead of react-native-navigation, you can read more on this link

Return a custom Alert in react native

I am trying to launch a custom Alert component from an onPress call from Touchable Highlight. I have been unable to get this to work, I have tried console logging from inside the custom Alert component render function and the code doesn't run to this point because I am unable to see this log. What is confusing me is that when I tested this with the React-Native Alert this did run and show that Alert. I would appreciate some help understanding what I am doing wrong here because I feel I am misunderstanding something. I have used the Alert component before and it works fine but in these instances it has only been when i have called the Alert directly not from onPress.
onPress() {
return (
<Alert
message={i18n('alerts.improvements')}
/>
)
}
render() {
return (
<TouchableHighlight onPress={() => this.onPress.bind(this)}>
<Text>Test Text</Text>
</TouchableHighlight>
)
}
The Alert Component with the console log that doesn't get hit:
class Alert extends Component{
props: {
message: string
}
state = {
modalVisible: false,
}
setModalVisible(visible) {
this.setState({modalVisible: visible});
}
render() {
console.log('modal')
return (
<Modal
animationStyle='fade'
transparent={true}
visible={!this.state.modalVisible}
onRequestClose={() => {}}
>
<View style={styles.container}>
<Text style={styles.text}>{this.props.message}</Text>
</View>
</Modal>
)
}
}
export default Alert
Rather than calling it onPress you can have default visible false and place it in render. Then add one more prop to your component which will manage visibility of it.
for example:
in component:
<Modal
animationType={'fade'}
transparent={true}
visible={this.props.isOpen}
onRequestClose={this.props.actionClose}>
while calling:
<ModalBox
isOpen={this.props.isOpen}
I have isOpen prop for visibility

How to bind(this) when passing a function as a prop in react native

I am working on a simple calculator app to learn react native. I have a button component that displays the number buttons. I need to pass it a function so that when the button is touched the state of the parent is updated to the new number.
Without the bind(this) it says this.setState is undefined. When I add bind(this) in the constructor all I get is a blank page in my app. My code is listed below.
constructor:
constructor() {
super();
this.state = {
total: 0,
display: 0
};
this._displayUpdate = this._displayUpdate.bind(this);
}
One row of calculator buttons:
<View style={styles.buttonRow}>
<NumButton numText={7} update={this._displayUpdate} />
<NumButton numText={8} update={this._displayUpdate} />
<NumButton numText={9} update={this._displayUpdate} />
<FuncButton funcText={'*'} />
</View>
NumButton Component:
export default class NumButton extends Component {
render() {
return (
<TouchableHighlight style={styles.buttonArea} onPress={this.props.update(this.props.numText)}>
<Text style={styles.buttonText}>{this.props.numText}</Text>
</TouchableHighlight>
)
}
}
Your parent bind is right. The problem is with the onPress of the TouchableHighlight in the NumButton component. You can't add code to execute to it, You should pass a function to it. You can use ES6 arrow function:
export default class NumButton extends Component {
render() {
return (
<TouchableHighlight style={styles.buttonArea}
onPress={()=>{ this.props.update(this.props.numText) }}
>
<Text style={styles.buttonText}>{this.props.numText}</Text>
</TouchableHighlight>
)
}
}

undefined is not an object(evaluating 'this.props._navigate.replace/push')

I'm new to React Native and trying ( followed a tutorial ) to move to another screen when a button is clicked, this is the updated code I have and a photo of the error I get when pressing the button.
index.ios.js:
export default class Application extends Component {
constructor(){
super();
}
renderScene(route, navigator){
if(route.name == 'login'){
return <Login navigator={navigator}/>
}else if(route.name == 'home'){
return <Home navigator={navigator}/>
}
}
render() {
return <Navigator
initialRoute={{name: 'login'}}
renderScene={this.renderScene.bind(this)}/>
}
}
LoginForm:
export default class LoginForm extends Component{
constructor(props){
super(props);
this.navigate = this.navigate.bind(this);
}
navigate(routeName){
this.props.navigator.replace({
name: routeName,
Component: Home
});
}
render(){
return(
<View style={mStyle.container}>
<StatusBar barStyle='light-content'/>
<TouchableOpacity>
<Text style={mStyle.btnText}>
LOGIN WITH FACEBOOK
</Text>
</TouchableOpacity>
<TouchableOpacity onPress={()=>this.navigate('home')}>
<Text style={mStyle.noLoginTxt}>
CONTINUE WITHOUT LOGIN
</Text>
</TouchableOpacity>
</View>
);
}
}
I'm trying to move from login screen to home screen when button is clicked.
I get this problem when pressing the button on the emulator:
A couple of problems that you are facing.
1.- The syntax is:
this.props.navigator.{any_method}
Such as:
this.props.navigator.push
this.props.navigator.replace
Not
this.props._navigate.{any_method}
2.- If you have child views make sure you are sending to the childs the Navigator property such as.
<View>
<MyChildComponent navigator={this.props.navigator} />
</View>
3.- Make sure your child view gets the props from the parent on the constructor.
Change
constructor(){
super();
this._navigate = this._navigate.bind(this);
}
To
constructor( props ){
super( props );
// The following line is not required since you are using an arrow function to call this one.
// this._navigate = this._navigate.bind(this);
}
It is because there is a mismatch between property you use in Navigator and in your component
Change
_navigate(name){
this.props._navigate.replace({ //I also tried push, same problem.
name
});
}
to
_navigate(name){
this.props.navigator.replace({ //I also tried push, same problem.
name
});
}