Modal and FlatList - react-native

Question

i work on my first react-native project and its also my firts javascript work. I want at least a news-app with own database informations. The backend is already finish. Now im in struggle with the app- i want an Popup with Modal with informations from my api like news_image, news_content and news_title. The News are in the FlatList and now i want to click on a item to show the content in an modal popup. so, here is my code where im struggle. i get always an error. so how can i fix this problem? tanks a lot!
import React from "react";
import {
AppRegistry,
FlatList,
Image,
Platform,
ScrollView,
StyleSheet,
Text,
TouchableOpacity,
View,
ActivityIndicator,
ListView,
YellowBox,
Alert,
TextInput
} from "react-native";
import { WebBrowser } from "expo";
import Button from "react-native-button";
import Modal from "react-native-modalbox";
import Slider from "react-native-slider";
import { MonoText } from "../components/StyledText";
export default class NewsFeed extends React.Component {
static navigationOptions = {
title: "HomeScreen"
};
constructor(props) {
super(props);
this.state = {
isLoading: true
};
YellowBox.ignoreWarnings([
"Warning: componentWillMount is deprecated",
"Warning: componentWillReceiveProps is deprecated"
]);
}
FlatListItemSeparator = () => {
return (
<View
style={{
height: 0.5,
width: "100%",
backgroundColor: "#000"
}}
/>
);
};
webCall = () => {
return fetch("http://XXXXXXXXXXXX.com/connection.php")
.then(response => response.json())
.then(responseJson => {
this.setState(
{
isLoading: false,
dataSource: responseJson
},
function() {
// In this block you can do something with new state.
}
);
})
.catch(error => {
console.error(error);
});
};
onClose() {
console.log("Modal just closed");
}
onOpen() {
console.log("Modal just opened");
}
onClosingState(state) {
console.log("the open/close of the swipeToClose just changed");
}
componentDidMount() {
this.webCall();
}
render() {
if (this.state.isLoading) {
return (
<View
style={{ flex: 1, justifyContent: "center", alignItems: "center" }}
>
<ActivityIndicator size="large" />
</View>
);
}
return (
<View style={styles.MainContainer}>
<FlatList
data={this.state.dataSource}
ItemSeparatorComponent={this.FlatListItemSeparator}
renderItem={({ item }) => (
<View style={{ flex: 1, flexDirection: "row" }}>
<Image
source={{ uri: item.news_image }}
style={styles.imageView}
/>
<Text
onPress={() => this.refs.modal.open()}
style={styles.textView}
>
{item.news_title}
{"\n"}
<Text style={styles.textCategory}>{item.author}</Text>
</Text>
<Text style={styles.textViewDate}>{item.created_at}</Text>
<Modal
style={[styles.modal]}
position={"bottom"}
ref={"modal"}
swipeArea={20}
>
<ScrollView>
<View style={{ width: "100%", paddingLeft: 10 }}>
{item.news_content}
</View>
</ScrollView>
</Modal>
</View>
)}
keyExtractor={(item, index) => index.toString()}
/>
</View>
);
}
}
const styles = StyleSheet.create({
MainContainer: {
justifyContent: "center",
flex: 1,
margin: 5
},
imageView: {
width: "25%",
height: 100,
margin: 7,
borderRadius: 7
},
textView: {
width: "100%",
height: "100%",
textAlignVertical: "center",
padding: 10,
fontSize: 20,
color: "#000"
},
textViewDate: {
width: "30%",
textAlignVertical: "center",
padding: 15,
color: "#afafaf"
},
textCategory: {
color: "#d3d3d3",
fontSize: 12
},
modal: {
justifyContent: "center",
alignItems: "center",
height: "90%"
}
});

Answer 1

Check the code below and compare it with your code.
I am not sure where your error is located or what your exact error is, but you can check the example code below, which is similar to yours, for comparison.
I am using 'Axios' over fetch() because of the automatic transformation to JSON and some other beneficial stuff.
npm install --save axios
Code:
import React, { Component } from 'react'
import {
ActivityIndicator,
FlatList,
Image,
ScrollView,
Text,
TouchableOpacity,
View
} from 'react-native';
import Axios from 'axios';
import Modal from "react-native-modalbox";
export default class NewsFeed extends Component {
constructor(props) {
super(props);
this.state = {
dataSource: [],
selectedIndex : -1
}
}
componentDidMount = () => {
Axios.get('<URL>')
.then(response => {
const { data } = response;
this.setState({dataSource : data});
}).catch(error => {
const { data } = error;
console.log(data);
});
}
_openModal = index => {
this.setState({ selectedIndex : index });
this.modalReference.open();
}
_renderSeparator = () => {
return <View style={{ flex: 1, borderBottomWidth: 0.5, borderBottomColor: '#000000' }} />
}
_renderItem = ({item, index}) => {
const {news_image, news_title, news_content, author, created_at} = item;
return <TouchableOpacity onPress={() => this._openModal(index)} >
<View style={{ flex: 1, flexDirection: 'row' }}>
<Image style={{ flex: 1, width: null, height: 200 }} source={{ uri: news_image }} />
<Text>{news_title}</Text>
<Text>{author}</Text>
<Text>{created_at}</Text>
</View>
</TouchableOpacity>;
}
render = () => {
const { dataSource, selectedIndex } = this.state;
const { news_content } = dataSource[selectedIndex];
return dataSource.length === 0 ?
<View style={{ flex: 1, justifyContent: "center", alignItems: "center" }}>
<ActivityIndicator size="large" />
</View> :
<View style={styles.MainContainer}>
<FlatList
data={dataSource}
keyExtractor={(item, index) => index.toString()}
ItemSeparatorComponent={this._renderSeparator}
renderItem={this._renderItem}
/>
<Modal ref={reference => modalReference = reference}>
<ScrollView style={{ flex: 1, padding: 20 }}>
<Text>{news_content}</Text>
</ScrollView>
</Modal>
</View>
}
}

Answer 2

I think the issue is in modal,
Can you re-write the code like below?
return (
<View style={styles.MainContainer}>
<FlatList
data={this.state.dataSource}
ItemSeparatorComponent={this.FlatListItemSeparator}
renderItem={({ item }) => (
<View style={{ flex: 1, flexDirection: "row" }}>
<Image source={{ uri: item.news_image }} style={styles.imageView} />
<Text onPress={() => { this.setState({ item: item.news_content }, () => this.refs.modal.open()); }} style={styles.textView}>
{item.news_title}
<Text style={styles.textCategory}>{item.author}</Text>
</Text>
<Text style={styles.textViewDate}>{item.created_at}</Text>
</View>
)}
keyExtractor={(item, index) => index.toString()}
/>
<Modal
style={[styles.modal]}
position={"bottom"}
ref={"modal"}
swipeArea={20}
>
<ScrollView>
<View style={{ width: "100%", paddingLeft: 10 }}>
{this.state.item}
</View>
</ScrollView>
</Modal>
</View>
);
Only single modal is enough for popup screen.
And you can try this also,
Change your reference to
ref={ref => this.modalRef = ref}
And use like this,
this.modalRef.open()