[英]JSON Parse error: Unexpected identifier "undefined" when trying to parse an object from an array (React-Native)
[英]Getting JSON Parse error: Unexpected identifier "undefined" when using React native & React navigation?
我對 React Native 還很陌生,所以如果這個問題看起來很愚蠢,我很抱歉,在問這個問題之前,我已經嘗試了幾個小時來讓它工作。
我正在嘗試使用 firebase 數據庫將數據從文本輸入傳遞到下一個屏幕。
我不斷收到錯誤 JSON Parse error: Unexpected identifier "undefined",我在我的兩個文件下面附加了一個,一個是文本輸入 (InputForm.js),另一個是我想在屏幕上顯示該數據 (ASTConfig1screen)
如果有人能幫助解決這個問題,你真的是一個超級巨星!
InputForm.js
import React, { Component } from 'react';
import { StyleSheet, ScrollView, ActivityIndicator, View, TextInput } from 'react-native';
import { Button } from 'react-native-elements';
import firebase from '../Firebase';
import { withNavigation } from 'react-navigation';
class InputForm extends Component {
constructor() {
super();
this.ref = firebase.firestore().collection('boards');
this.state = {
name: '',
inventoryclass: '',
outlet: '',
isLoading: false,
};
}
updateTextInput = (text, field) => {
const state = this.state
state[field] = text;
this.setState(state);
}
saveBoard() {
this.setState({
isLoading: true,
});
this.ref.add({
name: this.state.name,
inventoryclass: this.state.inventoryclass,
outlet: this.state.outlet,
}).then((docRef) => {
this.setState({
name: '',
outlet: '',
inventoryclass: '',
isLoading: false,
});
this.props.navigation.navigate('ASTConfig1');
})
.catch((error) => {
console.error("Error adding document: ", error);
this.setState({
isLoading: false,
});
});
}
render() {
if(this.state.isLoading){
return(
<View style={styles.activity}>
<ActivityIndicator size="large" color="#ffa500"/>
</View>
)
}
return (
<ScrollView style={styles.container}>
<View style={styles.subContainer}>
<TextInput style={styles.inputtext}
placeholder={'Name'}
placeholderTextColor="white"
value={this.state.name}
onChangeText={(text) => this.updateTextInput(text, 'name')}
/>
</View>
<View style={styles.subContainer}>
<TextInput style={styles.inputtext}
multiline={true}
numberOfLines={4}
placeholder={'Inventory Class'}
placeholderTextColor="white"
value={this.state.inventoryclass}
onChangeText={(text) => this.updateTextInput(text, 'inventoryclass')}
/>
</View>
<View style={styles.subContainer}>
<TextInput style={styles.inputtext}
placeholder={'Outlet'}
placeholderTextColor="white"
value={this.state.outlet}
onChangeText={(text) => this.updateTextInput(text, 'outlet')}
/>
</View>
<View style={styles.button}>
<Button
large
leftIcon={{name: 'save'}}
title='Save'
onPress={() => this.saveBoard()} />
</View>
</ScrollView>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
padding: 20
},
subContainer: {
flex: 1,
marginBottom: 20,
padding: 5,
borderBottomWidth: 2,
borderBottomColor: '#CCCCCC',
},
inputtext: {
color: 'white',
fontSize: 20
},
activity: {
position: 'absolute',
left: 0,
right: 0,
top: 0,
bottom: 0,
alignItems: 'center',
justifyContent: 'center'
}
})
export default withNavigation(InputForm);
這是我想在這個屏幕上顯示數據的地方
ASTConfig1.js
import React from 'react';
import {
View,
Text,
StyleSheet,
Button,
ImageBackground,
StatusBar,
SafeAreaView,
TextInput,
ScrollView,
UIManager,
ActivityIndicator
}
from 'react-native';
import {AccordionList} from "accordion-collapse-react-native";
import { Separator } from 'native-base';
import {widthPercentageToDP as wp, heightPercentageToDP as hp} from 'react-native-responsive-screen';
import firebase from '../Firebase';
import Logo from '.././components/Logo';
import Colors from '.././constants/Colors';
import Search from '.././components/Search';
import InputForm from '.././components/InputForm';
class ASTConfig1Screen extends React.Component {
static navigationOptions = {
title: 'ASTConfig1',
};
constructor(props) {
super(props);
this.state= {
isLoading: true,
board: {},
key: '',
status:true,
text: '',
list:[
{
title: 'Getting Started',
body: 'React native Accordion/Collapse component, very good to use in toggles & show/hide content'
},
{
title: 'Components',
body: 'AccordionList,Collapse,CollapseHeader & CollapseBody'
},
{
title: 'Test',
body: 'AccordionList,Collapse,CollapseHeader & CollapseBody'
}
],
}
}
componentDidMount() {
const { navigation } = this.props;
const ref = firebase.firestore().collection('boards').doc(JSON.parse(navigation.getParam('boardkey')));
ref.get().then((doc) => {
if (doc.exists) {
this.setState({
board: doc.data(),
key: doc.id,
isLoading: false
});
} else {
console.log("No such document!");
}
});
}
_head(item){
return(
<Separator bordered style={{alignItems:'center'}}>
<Text>{item.title}</Text>
</Separator>
);
}
_body(item){
return (
<View style={{padding:10}}>
<Text style={{textAlign:'center'}}>{item.body}</Text>
</View>
);
}
ShowHideTextComponentView = () =>{
if(this.state.status == true)
{
this.setState({status: false})
}
else
{
this.setState({status: true})
}
}
render() {
if(this.state.isLoading){
return(
<View style={styles.activity}>
<ActivityIndicator size="large" color="#0000ff" />
</View>
)
}
return (
<View style={styles.screen}>
<ImageBackground
source={require('.././assets/Img/BackGround2.png')}
style={styles.background}>
</ImageBackground>
<SafeAreaView>
<View style={{flex: 1, justifyContent: 'space-between', width: wp('80%')}}>
<View style={styles.logotop}>
<Logo/>
</View>
<View style={styles.editstock}>
<Text style={styles.editstocktext}>EDIT STOCK LIST:</Text>
</View>
{/*Start of 3 buttons Firebase*/}
<View style={styles.three}>
<View style={styles.edit1}>
<Text style={styles.textheader}>{this.state.board.name}</Text>
<Button style={styles.edit} title='Edit' ></Button>
</View>
<View style={{padding: 3}}></View>
<View style={styles.edit2}>
<Text style={styles.text}>{this.state.board.inventoryclass}</Text>
<Button style={styles.edit} title='Edit' ></Button>
</View>
<View style={styles.edit3}>
<Text style={styles.text}>{this.state.board.outlet}</Text>
<Button style={styles.edit} title='Edit' ></Button>
</View>
</View>
{/*End of 3 buttons Firebase*/}
{/*Start of AccordionList*/}
<ScrollView>
<View style={styles.middle}>
<AccordionList
list={this.state.list}
header={this._head}
body={this._body}
/>
</View>
</ScrollView>
{/*End of AccordionList*/}
{/*Start of Search*/}
<View>
{
this.state.status ? null : <View style={styles.bottom}>
<Text style={styles.textbottom}>SEARCH FOR NEW ITEMS:</Text>
<Search />
</View>
}
<Button title="ADD" onPress={this.ShowHideTextComponentView} />
</View>
</View>
</SafeAreaView>
</View>
);
};
};
{/*End of Search*/}
export default ASTConfig1Screen;
但它返回錯誤 - 添加文檔時出錯:[SyntaxError: SyntaxError: SyntaxError: JSON Parse error: Unexpected identifier "undefined"
在 inputform.js saveBoard 函數中,你應該
this.props.navigation.navigate('Details', {
'ASTConfig1': docRef
});
並從其他文件中刪除 JSON.parse
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