Invariant Violation: Invariant Violation: Element type is invalid: expected a string (for built-in components) but got: undefined

I'm getting the above error while i'm trying to run my application.

This is the error that pops up when I hover the mouse over the open bracket of render () in App.js file.

Edit: Added codes

App.js

import React from 'react';
import StyleSheet, Text, View from 'react-native';

import StackNavigator from 'react-navigation';
import Login from 'apps/components/Login';

const NavigationApp = StackNavigator(
Home: screen: Login
,,
navigationOptions:
header: false,


);

export default class App extends React.Component
render()
return (
<NavigationApp />
);




Login.js

import React from 'react';
import StyleSheet, Text, View, TextInput, AsyncStorage,
ToacheableOpacity,KeyboardAvoidingView from 'react-native';
import StackNavigator from 'react-navigation';

export default class Login extends React.Component
constructor (props)
super(props);
this.state=
username:'',
password:'',



componentDidMount()
this._loadInitialState().done();


_loadInitialState = async () =>
var value= await AsyncStorage.getItem('user');
if (value != null)
this.props.navigation.navigate('profile');



render()
return (
<KeyboardAvoidingView behavior='padding' style=styles.wrapper>
<View style=styles.container>
<TextInput style=styles.textInput
placeholder='Usuario' onChangeText=(username)=> this.setState(username)/>

<TextInput style=styles.textInput
placeholder='Clave' onChangeText=(password)=> this.setState(password)/>

<ToacheableOpacity>
style=styles.button onPressthis.login
<Text style=styles.buttonText>Iniciar Seccion</Text>
</ToacheableOpacity>
</View>
</KeyboardAvoidingView>
);


login = () =>
fetch('https://wb382.com/api/mobile/login.php',
method: 'post',
headers:
'Accept': 'application/json',
'Content-Type': 'application/json',
,
body: JSON.Stringify(
username: this.state.usersame,
password: this.state.password,
)
)

.then((response)=>response.json())
.then((res)=>
if (res.success===true)
AsyncStorage.setItem('user',res.user);
this.props.navigation.navigate('profile')
else
alert(res.message);

)



const styles = StyleSheet.create(
wrapper:
flex: 1,
,
container:
flex: 1,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: '#000',
paddingLeft: 40,
paddingRight: 40,
,
buttonText:
fontSize: 26,
color: '#fff',
,
textInput:
alignSelf: 'stretch',
padding: 16,
marginBotton: 20,
backgroundColor: '#fff',
,
button:
alignSelf: 'stretch',
backgroundColor: '#1fd100',
padding: 20,
alignItems: 'center',

);


I don't know which of these file is producding the error.

To simulate these codes, I'm also hosting my codes at expo.io

https://snack.expo.io/@wilson382/my-first-mobile-app

1 Answer
1

Login component has an error in "ToacheableOpacity". In import statement and render method both are wrong written. It is TouchableOpacity. I've edited your demo code, and changing to the right name fixed the error.

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