Not able to parse json file and display data - react native - json

Question

import React, { Component } from 'react';
import {
AppRegistry,
StyleSheet,
Text,
View,
Navigator,
TouchableOpacity,
Image,
TouchableHighlight,
Alert,
TextInput
} from 'react-native';
import Button from 'react-native-button'
import {Actions} from 'react-native-router-flux'
import Home from './Home'
export class Temp extends Component{
constructor(props) {
super(props);
this.state = {
data: '',
textinput:'',
}
state={
shouldShow: false
}
}
componentDidMount(){
this._onPressButtonGET();
}
_onPressButtonPOST(){
fetch("url", {
method: "POST",
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
},
body: JSON.stringify({
"entryDate":"3/2/2017 2:00 AM",
"systol": this.state.textinput,
"mobileType":"ANDROID",
"userName":"menutest",
})})
.then((response) => response.json())
.then((responseData) => {
Alert.alert(
"Blood pressure data",
"Blood pressure data - " + JSON.stringify(responseData)
)
}).catch((error) => {
console.error(error);
})
.done();
}
_onPressButtonGET(){
fetch("url", {
method: "POST",
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
},
body: JSON.stringify({"mobileType":"ANDROID","userName":"menutest"})})
.then((response) => response.json())
.then((responseData) => {
this.setState({ data : JSON.stringify(responseData)})
}) .catch((error) => {
console.error(error);
})
.done();
}
render(){
return(
<View>
<TouchableHighlight onPress={this._onPressButtonPOST.bind(this)}>
<Text>Add</Text>
</TouchableHighlight>
<TouchableOpacity style= {{left:300,top:-20, }}
onPress={()=>{ this.setState({ shouldShow: !this.state.shouldShow })}}
><Text>Edit</Text></TouchableOpacity>
{this.state.shouldShow ? <TextInput placeholder='systol'
onChangeText={(text) => this.setState({textinput: text})}
/> : null}
<TouchableHighlight onPress={this._onPressButtonGET.bind(this)}>
<Text>show</Text>
</TouchableHighlight>
<Text>{this.state.data}</Text>
</View>
);
}
}
module.exports = Temp;
I need to parse json file and display the data that is entryDate and systol. but i am not able to parse it. but in the above code i am able to display all the data.
{
"List": [
{
"entryDate": "03/02/2017",
"entryDateTime": "03/02/2017 2:00 AM",
"entryTime": "2:00 AM",
"systol": "120"
},
{
"entryDate": "03/02/2017",
"entryDateTime": "03/02/2017 2:00 AM",
"entryTime": "2:00 AM",
"systol": "121"
},
{
"entryDate": "03/02/2017",
"entryDateTime": "03/02/2017 2:00 AM",
"entryTime": "2:00 AM",
"systol": "120"
},
{
"entryDate": "03/02/2017",
"entryDateTime": "03/02/2017 2:00 AM",
"entryTime": "2:00 AM",
"systol": "122"
},
{
"entryDate": "03/02/2017",
"entryDateTime": "03/02/2017 2:00 AM",
"entryTime": "2:00 AM",
"systol": "123"
}
]
}
this is my json file.
and i want output like:
entryDate:03/02/2017
systol:120
entryDate:03/02/2017
systol:121
entryDate:03/02/2017
systol:122
entryDate:03/02/2017
systol:123

Answer 1

set data state to null
this.state = {
data: null
};
change
this.setState({ data : JSON.stringify(responseData)})
to
this.setState({ data : responseData })
Then display relevant data inside your render like this -
<View>
....
....
{this.state.data &&
this.state.data.List.map((d,i) => (
<View key={i}>
<Text>{d.entryDate}</Text>
<Text>{d.systol}</Text>
</View>
))}
</View>