Hello I am making a react native app with expo. Following is my app.js file:
import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
import {createBottomTabNavigator} from 'react-navigation';
import WelcomeScreen from "./screens/WelcomeScreen";
import AuthScreen from "./screens/AuthScreen";
export default class App extends React.Component {
render() {
const MainNavigator = createBottomTabNavigator({
Welcome: WelcomeScreen,
Auth: AuthScreen
});
return (
<View style={styles.container}>
<MainNavigator/>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
alignItems: 'center',
justifyContent: 'center',
},
});
and following is my package.json file:
{
"main": "node_modules/expo/AppEntry.js",
"private": true,
"dependencies": {
"expo": "^28.0.0",
"react": "16.3.1",
"react-native": "https://github.com/expo/react-native/archive/sdk-28.0.0.tar.gz",
"react-navigation": "^2.6.2"
}
}
The app is running without any errors but it does not display the bottom navigation tab! I have checked the syntax from the official documentation as well and i fear it may be due to version of react-navigation.
Any help would be appreciated.
Following is my welcomescreen component file:
import React, {Component} from 'react';
import {Text, View} from "react-native";
class WelcomeScreen extends Component{
render(){
return(
<View>
<Text>
Hello this is working!
</Text>
</View>
);
}
}
export default WelcomeScreen;
auth component is also same except the change of name.
Version is not the issue. The issue is with the custom StyleSheet and <View/> Component
You can View the edited app here
In case u want to try in uer app package.json is:
{
"dependencies": {
"#expo/vector-icons": "6.2.1",
"react-native-elements": "0.18.5",
"react-navigation": "^2.6.2"
}
}
and App.js is:
import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
import { createBottomTabNavigator } from 'react-navigation'; // Version can be specified in package.json
class AuthScreen extends React.Component{
render(){
return(
<View>
<Text>
AuthScreen Works!
</Text>
</View>
);
}
}
class WelcomeScreen extends React.Component{
render(){
return(
<View>
<Text>
Hello this is working!
</Text>
</View>
);
}
}
export default class App extends React.Component {
render() {
const MainNavigator = createBottomTabNavigator({
Auth: { screen: AuthScreen },
Welcome: { screen: WelcomeScreen },
});
// return (
// <View style={styles.container}>
// <MainNavigator/>
// </View>
// );
return <MainNavigator/>
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
alignItems: 'center',
justifyContent: 'center',
},
});
Try to have a stack navigator as your first screen and then try to load Welcome screen and Other screen as Bottom Tab Navigator, I have used this structure in many of my apps try this https://github.com/davekedar/React-Navigation-V2-Authflow
I solved this problem by upgrading to
"react-navigation": "^2.13.0"
Encountered this today with "react-navigation": "^4.3.9".
Fixed by setting <View style={{ flex: 1 }}> instead of just <View>. This problem does not occur if you wrap the navigator in something other than <View> (i.e. <Fragment>).
https://github.com/react-navigation/react-navigation/issues/8449
https://reactnavigation.org/docs/troubleshooting/#nothing-is-visible-on-the-screen-after-adding-a-view
Related
I'm new to React Native and tried to follow the lesson "Organize a React Native Project" so I moved the code from App.js to App/index.js and deleted App.js. That works fine in the Android simulator but not in the Web browser.
There I get this error:
Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object.
Check the render method of `ExpoRootComponent`.
▶ 24 stack frames were collapsed.
registerRootComponent
C:/Users/me/Documents/src/launch/registerRootComponent.web.tsx:14
11 | const RootComponent: React.FC<P> = props => <App {...props} />;
12 | AppRegistry.registerComponent('main', () => RootComponent);
13 | const rootTag = document.getElementById('root') ?? document.getElementById('main');
> 14 | AppRegistry.runApplication('main', { rootTag });
15 | }
My app code is really simple, it is the default one from the Expo basic template. index.js :
import { StatusBar } from 'expo-status-bar';
import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
export default function App() {
return (
<View style={styles.container}>
<Text>Open up App.js to start working on your app!</Text>
<StatusBar style="auto" />
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
alignItems: 'center',
justifyContent: 'center',
},
});
I have run the commands expo start and npm start but no difference.
Provide (the default) AppEntry.js in case it is of interest:
import registerRootComponent from 'expo/build/launch/registerRootComponent';
import App from '../../App';
registerRootComponent(App);
You need to change the package.json file to have the main property as follows.
"main": "YourFilePath/YourEntryFile.js"
in your case "main": "App/index.js",
and in the component that you want to make the root component,
Class-based component YourEntryFile.js
import { registerRootComponent } from 'expo';
import React from 'react';
import { View } from 'react-native';
class App extends React.Component {
render() {
return <View />;
}
}
registerRootComponent(App); //this is important
Functional component YourEntryFile.js
import { registerRootComponent } from 'expo';
import { StatusBar } from 'expo-status-bar';
import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
const App = () => {
return (
<View style={styles.container}>
<Text>Open up App.js to start working on your app!</Text>
<StatusBar style="auto" />
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
alignItems: 'center',
justifyContent: 'center',
},
});
registerRootComponent(App) //This line is important
Please refer to expo docs for more info
I'm new to react-native and trying to set up my app with mobx for state management, when trying to inject rootStore into my HomeScreen component I get the following error:
Error: C:\xampp\htdocs\second-try\screens\HomeScreen.js: Leading decorators must be attached to a class declaration
This is my component, as you see I'm suing function based component and I get a warning, but how can I use components ass Class and inject mobx stre into my react-native component.
My HomeScreen file:
import * as React from 'react';
import { StatusBar } from 'expo-status-bar';
import { View, Text, StyleSheet } from 'react-native';
#inject(stores => ({
postStore: rootStore.postStore,
//authStore: rootStore.authStore,
})
)
//ERROR IS RIGHT
#observer
const HomeScreen = function()
{
return (
<View style={styles.container}>
<Text>{postStore.postMessage}</Text>
<StatusBar style="auto" />
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
alignItems: 'center',
justifyContent: 'center',
},
});
export default HomeScreen;
My goal is to render my homescreen from an external .js file called home.js. This .js file is located in a directory below root project directory in a a folder called "screens". I am having trouble rendering the contents in that home.js file. If I move the code from my home.js file back into the app.js file it works perfectly fine. I am trying to take a modular approach since this is best practice and would rather not stuff everything into the app.js file. I plan on creating more screens in the near future but am trying to wrap my mind around the basics first.
My current code in the app.js file
// In App.js in a new project
import React from "react";
import { View, Text } from "react-native";
import { createStackNavigator, createAppContainer } from "react-navigation";
import HomeScreen from './screens/home.js';
/*
class DetailsScreen extends React.Component {
render() {
return (
<View style={{ flex: 1, alignItems: "center", justifyContent: "center" }}>
<Text>Details Screen</Text>
</View>
);
}
}
*/
export default createAppContainer(AppNavigator);
const AppNavigator = createStackNavigator(
{
Home: HomeScreen,
//Details: DetailsScreen
},
{
initialRouteName: "Home"
}
);
The code in my home.js file is
import React from "react";
import { View, Text } from "react-native";
class HomeScreen extends React.Component {
render() {
return (
<View style={{ flex: 1, alignItems: "center", justifyContent: "center" }}>
<Text>Home Screen</Text>
</View>
);
}
}
Edit 1:
My current error is
undefined is not an object (evaluating 'Component.router')
createNavigationContainer
C:\Repos\demoProject\node_modules#react-navigation\native\src\createAppContainer.js:88:30
<unknown>
C:\Repos\demoProject\App.js:24:34
loadModuleImplementation
C:\Repos\demoProject\node_modules\metro\src\lib\polyfills\require.js:331:6
<unknown>
C:\Repos\demoProject\node_modules\expo\AppEntry.js:4
loadModuleImplementation
C:\Repos\demoProject\node_modules\metro\src\lib\polyfills\require.js:331:6
guardedLoadModule
C:\Repos\demoProject\node_modules\metro\src\lib\polyfills\require.js:197:45
global code
<unknown file>:0
You're not exporting your HomeScreen component, you can do this by adding an export default infront of the class definition, or underneath.
export default class HomeScreen extends React.Component {
render() {
return (
<View style={{ flex: 1, alignItems: "center", justifyContent: "center" }}>
<Text>Home Screen</Text>
</View>
);
}
}
Or
class HomeScreen extends React.Component {
render() {
return (
<View style={{ flex: 1, alignItems: "center", justifyContent: "center" }}>
<Text>Home Screen</Text>
</View>
);
}
}
export default HomeScreen
You're also attempting to export AppNavigator before it is instantiated. You need to move the export below.
const AppNavigator = createStackNavigator(
{
Home: HomeScreen,
//Details: DetailsScreen
},
{
initialRouteName: "Home"
}
);
export default createAppContainer(AppNavigator);
There is my code & the error below. I made some changes in the App.js file, & since then this issue has shown up. I had my router setup in this file originally, but then decided to move. I've tried other styles & it doesn't work either.
App.js
import React from 'react';
import { StyleSheet, Text, View, Navigator } from 'react-native';
import { Fonts } from './src/utils/Fonts';
import Menu from './app/components/Menu';
import Page from './app/components/Page';
import Router from './app/components/Router';
export default class App extends React.Component {
render() {
return (
<View style={styles.fonts}>
<Menu />
</View>
);
}
}
const styles = StyleSheet.create({
fonts: {
fontSize: 30,
fontWeight: 12,
fontFamily: Fonts.Baloo
},
});
Error
I had different styles & code on the Menu component before this issue & it worked fine, but now even when I make changes it doesn't go back to the original, just shows this same error.
Menu.js
import React from 'react';
import {
StyleSheet,
Text,
Image,
MenuItem,
Font,
View,
TextInput,
TouchableOpacity
} from 'react-native';
import { Actions } from 'react-native-router-flux';
export default class Menu extends React.Component {
render() {
return (
<View style={styles.container}>
<Text
style={styles.fonts}
onPress={() => Actions.page()}>
Navvi
</Text>
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#000',
},
});
I already commented it, but this is how your code should look like (in Menu.js):
export default class Menu extends React.Component {
render() {
return (
<View style={styles.container}>
<Text
style={styles.fonts}
onPress={() => Actions.page()}
>
{"Navvi"}
</Text>
</View>
);
}
}
Whenever I try to run my iOS simulator, I'm getting that error. All modules are installed, file path to my picture is correct, no errors being thrown within my IDE except for the one that's appearing in my simulator. Picture below of error.
Here's Login.js:
import React, {Component} from 'react';
import {StyleSheet, TextInput, Text, TouchableOpacity, KeyboardAvoidingView} from 'react-native';
class Login extends Component {
onButtonPress() {
this.props.navigator.push({
id: 'CreateAccount'
});
}
render() {
return(
<KeyboardAvoidingView behavior={"padding"} style={styles.container}>
<TextInput
style={styles.input}
returnKeyType={"next"}
keyboardType={"email-address"}
autoCorrect={false}
placeholder={"Email"}
/>
<TextInput
style={styles.input}
returnKeyType={"go"}
placeholder={"Password"}
secureTextEntry
/>
<TouchableOpacity>
<Text style={styles.loginAndCA}>Login</Text>
</TouchableOpacity>
<TouchableOpacity onPress={this.onButtonPress.bind(this)}>
<Text style={styles.loginAndCA}>Create Account</Text>
</TouchableOpacity>
</KeyboardAvoidingView>
);
}
}
const styles = StyleSheet.create({
container: {
padding: 20 // Length of text input boxes.
},
input: {
backgroundColor: '#DAE5FF',
padding: 20,
paddingHorizontal: 15,
marginBottom: 10,
borderRadius: 15
},
loginAndCA: {
fontSize: 40,
textAlign: 'center',
color: 'white',
fontFamily: 'Bodoni 72 Smallcaps',
paddingHorizontal: 10
}
});
export default Login;
Here's BackGround.js:
import React, {Component} from 'react';
import {StyleSheet, Image, View, Text} from 'react-native';
import Login from './Login';
class BackGround extends Component {
render() {
return(
<View style={styles.first}>
<Image style={styles.container} source={require('../pictures/smoke.jpg')}>
<View style={styles.second}>
<View>
<Text style={styles.title}>My App</Text>
</View>
<Login/>
</View>
</Image>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
alignItems: 'center',
width: null,
height: null,
backgroundColor: 'rgba(0,0,0,0)'
},
first: {
flex: 1
},
second: {
paddingTop: 290 // Moves both <TextInput> boxes down.
},
title: {
fontSize: 34,
textAlign: 'center',
justifyContent: 'center',
flexDirection: 'row',
fontFamily: 'Bodoni 72'
}
// movementTitle: {
// paddingBottom: 34
// }
});
export default BackGround;
Here's CreateAccount.js:
import React, {Component} from 'react';
import {Text} from 'react-native';
class CreateAccount extends Component {
render() {
return(
<Text>Must get to this page</Text>
);
}
}
export default CreateAccount;
Here's index.ios.js:
import React, {Component} from 'react';
import {View, StyleSheet, AppRegistry} from 'react-native';
import {Navigator} from 'react-native-deprecated-custom-components';
import BackGround from './components/BackGround';
import Login from "./components/Login";
import CreateAccount from "./components/CreateAccount";
export default class App extends Component {
render() {
return(
<View style={styles.back}>
<BackGround/>
<Navigator
initialRoute={{id: 'Login'}}
renderScene={this.navigatorRenderScene}
/>
</View>
);
}
navigatorRenderScene() {
_navigator = navigator;
switch(route.id) {
case 'Login':
return (<Login navigator={navigator} title="Login"/>);
case 'CreateAccount':
return (<CreateAccount navigator={navigator} title="Create Account" />);
}
}
}
const styles = StyleSheet.create({
back: {
flex: 1
}
});
AppRegistry.registerComponent('dendroApp', () => dendroApp);
React recently removed PropTypes from their core library as of React 15.5.
Add the line
import PropTypes from 'prop-types';
And call your proptypes directly from that.
It seems PropTypes is undefined. I don't see it declared anywhere in your code. You have to import it via a separate module as shown in the documents: PropTypes.
Update:
Perhaps a library you are using is using the now deprecated/non-supported React.PropTypes. I recommend using a more up to date library or actually going into the library and updating the package so it uses the new PropTypes from the separate package instead of React.PropTypes. This should fix your problem
Yes definitely, if you upgrade react: 15 or higher then you have to add import PropTypes from 'prop-types';
But recently I faced the same issue in "react": "16.0.0-beta.5" after I changed
"dependencies": {
"react": "16.0.0-alpha.12"
},
"devDependencies": {
"react-test-renderer": "16.0.0-alpha.12"
}
Then it found working fine. Hope it helps!