Develop Reference

React Native Android networking does not work

I run a React Native app on Android emulator but found networking does not work, I run it on iOS it works fine.
Here is the simple code:
import React from 'react';
import {StyleSheet, View, Text} from 'react-native';
export default () => {
React.useEffect(() => {
const useFetch = async () => {
try {
console.log('fetch ...');
let response = await fetch('https://mytestdomain.com');
console.log(response.status);
// let json = await response.json();
} catch (error) {
console.log(error);
}
};
useFetch();
const useXMLHttpRequest = async () => {
try {
var request = new XMLHttpRequest();
request.onreadystatechange = (e) => {
if (request.readyState !== 4) {
console.log(request.readyState);
return;
}
if (request.status === 200) {
console.log('success', request.responseText);
} else {
console.warn('error');
}
};
request.open('GET', 'https://mytestdomain.com');
request.send();
} catch (error) {
console.log(error);
}
};
useXMLHttpRequest();
}, []);
return (
<View style={styles.layout}>
<Text>React Native Android networking</Text>
</View>
);
};
const styles = StyleSheet.create({
layout: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
},
});
By call useFetch() I just see 'fetch ...' in console, even can not see response.status, and there is no error from catch.
By call useXMLHttpRequest() I see request.readyState is 1.
Thanks advance for any help

You probably should give this asynchronous log a more explicit message to find this specific one among other logs, like :
console.log("RS : " + response.status);
I tried to reproduce your issue, and I can't, it works on my Android simulator just fine.
Would you please share your console logs ?
A workaround is to use the #react-native-community/netinfo library to determine whether you have internet access or not.
Beware, it could be slow.
This library provides a listener with the connection details changes. Getting the connection details can be slow... you would have to test it on real devices to determine whether this workaround is efficient or not.
Quick Demo based on your source code :
[...]
import { StyleSheet, View, Text } from "react-native";
+import NetInfo from "#react-native-community/netinfo";
export default () => {
- React.useEffect(() => {
+ NetInfo.addEventListener((netInfo) => {
const useFetch = async () => {
try {
- console.log("fetch ...");
- let response = await fetch("https://mytestdomain.com");
- console.log(response.status);
- // let json = await response.json();
+ // Just because there is a connection, it does not mean that internet is accessible, so test both isConnected and isInternetReachable
+ if (netInfo.isConnected && netInfo.isInternetReachable) {
+ console.log("fetch ...");
+ let response = await fetch(
+ "https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch"
+ );
+ console.log("start 1");
+ console.log("success 1", response.status);
+ console.log("stop 1");
+ } else {
+ console.log("internet is not ready");
+ }
} catch (error) {
[...]

How can I send images/video and voice messages in React-native-Gifted-chat using render actions?

I want to send images/video in chat application, developed using React-native-gifted-chat and Firebase, How can I create action for them and call that actions to upload in firebase and send images/video?
Here is my code.
handleSendImage = () => {
console.log("handleSendImage");
};
renderActions(props) {
return (
<Actions
{...props}
// containerStyle={{
// width: 70,
// }}
icon={() => (
<Icon
name={"camera"}
size={30}
color={colors.btnBg}
font={"FontAwesome"}
onPress={this.handleSendImage}
/>
)}
onSend={(args) => console.log(args)}
/>
);
}
<GiftedChat
placeholder={"Hey!"}
alwaysShowSend
messages={messages}
onSend={(newMessage) => this.onSend(this.chatID(), newMessage)}
renderInputToolbar={this.renderInputToolbar}
renderActions={this.renderActions}
user={{
_id: senderId,
name: senderName,
}}
/>
How can I click on particular actions and send voice and images/video respectively?

Gifted chat has renderActions property itself so just need to create custom action to upload image/video and voice.
Here, I am attaching code for upload documents like PDF/Doc file.
To upload image/video you just need to change that package instead of I've used document-picker
const renderActions = (props) => {
return (
<Actions
{...props}
options={{
['Document']: async (props) => {
try {
const result = await DocumentPicker.pick({
type: [DocumentPicker.types.pdf],
});
console.log("image file",result)
} catch (e) {
if (DocumentPicker.isCancel(e)) {
console.log("User cancelled!")
} else {
throw e;
}
}
},
Cancel: (props) => { console.log("Cancel") }
}}
onSend={args => console.log(args)}
/>
)
};
Gifted-chat component
<GiftedChat
messages={messages}
showAvatarForEveryMessage={true}
onSend={messages => onSend(messages)}
renderActions={() => renderActions()}
user={{
_id: 2,
name: 'React Native',
avatar: 'https://placeimg.com/140/140/any',
}}
renderCustomView={renderCustomView}
/>

Unable to get jwt from backend server

What my app should do is it uses google oauth for login and the server will then return a create a user (if user has not been created) and log the user in (by creating session).
I am certain my backend works because i have tested everything with postman.
However, i am unable to handle the creation of user (if user has not been created) and console.log my jwt to assure myself that it is working. I am strongly convinced it has to do with my react native code below.
Furthermore, the log which says "this is not working" is not being printed in google chrome as well.
-
import React from 'react';
import { StyleSheet, Platform, Image, Text, View, ScrollView } from 'react-native';
import { GoogleSignin, statusCodes, GoogleSigninButton } from 'react-native-google-signin';
import NavigationManager from './containers/TabNavigator';
import PhoneStorageManager from './assets/jwtStorageManager';
GoogleSignin.configure({
forceConsentPrompt: true,
webClientId: '<client-id>
});
export default class App extends React.Component {
constructor() {
super();
this.state = {failed: "NOOO", user: null, jwt: null};
}
async componentDidMount() {
}
signIn = async () => {
try {
await GoogleSignin.hasPlayServices();
const userInfo = await GoogleSignin.signIn();
this.setState({ failed: "SUCCESS" });
this.setState({ user: userInfo });
const resp = await fetch('<url>', {
method: 'POST',
headers: {
Accept: 'application/json',
'Content-Type': 'application/json',
},
body: JSON.stringify({
session: {
token: userInfo.idToken,
authprovider: "google"
}
})
})
.then(response => response.json())
this.setState({ jwt: resp.jwt }, ()=> {
console.log(this.state.jwt, 'jwt');
PhoneStorageManager._storeData("key",this.state.jwt);
//so that i can use jwt for further api calls
});
console.log("this is not working");
} catch (error) {
if (error.code === statusCodes.SIGN_IN_CANCELLED) {
// user cancelled the login flow
this.setState({ failed: "CANCELLED" });
} else if (error.code === statusCodes.IN_PROGRESS) {
// operation (f.e. sign in) is in progress already
this.setState({ failed: "PROGRESS" });
} else if (error.code === statusCodes.PLAY_SERVICES_NOT_AVAILABLE) {
// play services not available or outdated
this.setState({ failed: "NO AVAIL" });
} else {
// some other error happened
this.setState({error: error});
this.setState({ failed: "some other error happened" });
}
}
}
render() {
if (this.state.jwt) {
console.log(this.state.jwt);
return (
<NavigationManager JWT={this.state.jwt}/>
);
}
else
return (
<View style={styles.container}>
<Image source={require('./assets/auditlogo.png')} style={[styles.logo]} />
<GoogleSigninButton
style={{ width: 192, height: 48 }}
size={GoogleSigninButton.Size.Wide}
color={GoogleSigninButton.Color.Dark}
onPress={this.signIn}
disabled={this.state.isSigninInProgress} />
<Text style= {styles.instructions}>
Please Sign in to continue.
</Text>
</View>
);
}
}
1) User presses google sign in button
2) Fetch api to create user if new user.
3) Fetch api to create session. (this returns jwt for further api calls)
4) Further api calls which uses jwt. (How do i get the jwt to be passed down?)

Cancel a fetch request in react-native

Is there any way to abort a fetch request on react-native app ?
class MyComponent extends React.Component {
state = { data: null };
componentDidMount = () =>
fetch('http://www.example.com')
.then(data => this.setState({ data }))
.catch(error => {
throw error;
});
cancelRequest = () => {
//???
};
render = () => <div>{this.state.data ? this.state.data : 'loading'}</div>;
}
i tried the abort function from AbortController class but it's not working !!
...
abortController = new window.AbortController();
cancelRequest = () => this.abortController.abort();
componentDidMount = () =>
fetch('http://www.example.com', { signal: this.abortController.signal })
....
Any help please !

You don't need any polyfill anymore for abort a request in React Native 0.60 changelog
Here is a quick example from the doc of react-native:
/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* #format
* #flow
*/
'use strict';
const React = require('react');
const {Alert, Button, View} = require('react-native');
class XHRExampleAbortController extends React.Component<{}, {}> {
_timeout: any;
_submit(abortDelay) {
clearTimeout(this._timeout);
// eslint-disable-next-line no-undef
const abortController = new AbortController();
fetch('https://facebook.github.io/react-native/', {
signal: abortController.signal,
})
.then(res => res.text())
.then(res => Alert.alert(res))
.catch(err => Alert.alert(err.message));
this._timeout = setTimeout(() => {
abortController.abort();
}, abortDelay);
}
componentWillUnmount() {
clearTimeout(this._timeout);
}
render() {
return (
<View>
<Button
title="Abort before response"
onPress={() => {
this._submit(0);
}}
/>
<Button
title="Abort after response"
onPress={() => {
this._submit(5000);
}}
/>
</View>
);
}
}
module.exports = XHRExampleAbortController;

I've written quite a bit actually about this subject.
You can also find the first issue about the OLD lack of AbortController in React Native opened by me here
The support landed in RN 0.60.0 and you can find on my blog an article about this and another one that will give you a simple code to get you started on making abortable requests (and more) in React Native too. It also implements a little polyfill for non supporting envs (RN < 0.60 for example).

You can Actually achieve this by installing this polyfill abortcontroller-polyfill
Here is a quick example of cancelling requests:
import React from 'react';
import { Button, View, Text } from 'react-native';
import 'abortcontroller-polyfill';
export default class HomeScreen extends React.Component {
state = { todos: [] };
controller = new AbortController();
doStuff = () => {
fetch('https://jsonplaceholder.typicode.com/todos',{
signal: this.controller.signal
})
.then(res => res.json())
.then(todos => {
alert('done');
this.setState({ todos })
})
.catch(e => alert(e.message));
alert('calling cancel');
this.controller.abort()
}
render(){
return (
<View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
<Text>Details Screen</Text>
<Button title="Do stuff" onPress={() => { this.doStuff(); }} />
</View>
)
}
}
So basically in this example, once you click the 'doStuff' button, the request is immediately cancelled and you never get the 'done' alert. To be sure, it works, try and comment out these lines and click the button again:
alert('calling cancel');
this.controller.abort()
This time you will get the 'done' alert.
This is a simple example of hoe you can cancel a request using fetch in react native, feel free to adopt this to your own use case.
Here is a link to a demo on snackexpo https://snack.expo.io/#mazinoukah/fetch-cancel-request
hope it helps :)

the best solution is using rxjs observables + axios/fetch instead of promises, abort a request => unsubscribe an observable :
import Axios from "axios";
import {
Observable
} from "rxjs";
export default class HomeScreen extends React.Component {
subs = null;
doStuff = () => {
let observable$ = Observable.create(observer => {
Axios.get('https://jsonplaceholder.typicode.com/todos', {}, {})
.then(response => {
observer.next(response.data);
observer.complete();
})
});
this.subs = observable$.subscribe({
next: data => console.log('[data] => ', data),
complete: data => console.log('[complete]'),
});
}
cancel = () =>
if (this.subs) this.subs.unsubscribe()
componentWillUnmount() {
if (this.subs) this.subs.unsubscribe();
}
}
That is it :)

How to Cache API data using AsyncStorage React Native

Fairly new to React native and its concepts. I have been playing with RN for a while to create an application to fetch API data from
http://jsonplaceholder.typicode.com/photos
I have been looking into the documentation of AsyncStorage to implement how i can cache the API data so that upon terminating the application, it doesn't have to deal with fetching the data from web again and again, but wasn't successfully able to implement it.
It will be great if you can provide me help/suggestion based on it. I have included my source code for the 2 important files in my application, along with the a Test.js file with how i was trying to achieve.
import React, {Component} from 'react';
import { FlatList, View, Text, AsyncStorage, ActivityIndicator } from 'react-native';
import axios from 'axios';
import GalleryDetail from './GalleryDetail';
class GalleryList extends Component {
state = { photos: []};
componentDidMount() {
axios.get('http://jsonplaceholder.typicode.com/photos')
.then(response => this.setState({ photos: response.data }))
.catch((error)=> console.warn("fetch Error: ", error));
}
getPhotos = async()=> {
try {
photos = await AsyncStorage.getItem('GalleryPhotos');
}
catch (error) {
console.error(error);
}
}
savePhotos(){
AsyncStorage.setItem('GalleryPhotos', this.state.photos);
console.log('works !');
}
renderPhoto = ({item})=> {
return <GalleryDetail photo={item}/>
}
keyExtractor = (photo, index) => photo.id;
render () {
if(!this.state.photos){
return <ActivityIndicator/>;
}
return (
<FlatList
data = {this.state.photos}
keyExtractor={this.keyExtractor}
renderItem={this.renderPhoto}
/>
);
}
}
export default GalleryList;
and GalleryDetail linked with GalleryList-
import React, {Component} from 'react';
import { Text, View, Image } from 'react-native';
import Card from './Card';
import CardSection from './CardSection';
const GalleryDetail = (props)=> {
return (
<Card>
<CardSection style = {styles.headerContentStyle}>
<Image
style={styles.thumbnailStyle}
source = {{ uri: props.photo.thumbnailUrl}}/>
<Text style= {styles.textStyle}>{props.photo.title} </Text>
</CardSection>
</Card>
);
};
const styles = {
headerContentStyle: {
flexDirection: 'column',
justifyContent: 'space-around'
},
thumbnailStyle: {
height: 60,
width: 60
},
textStyle: {
fontSize: 12,
//textAlign: 'right',
flexDirection: 'row',
justifyContent: 'flex-end',
flex: 1,
flexWrap: 'wrap',
marginLeft: 5,
marginRight: 5,
}
}
export default GalleryDetail;
My method of trying was that-
Upon launching the application, it will first look in asyncStorage, if it finds the data- it fetches from async otherwise going to the web,fetching and storing again for later use.
I tried to implement somewhat like this in a separate file since i dint wanted to breakdown my already running app. The weird broken syntax is
State = {
photos: []
}
componentDidMount() {
// just a variable acting to fetch data from the stored keyvalue pair
check = AsyncStorage.getItem("PhotosKey").then((response) => {
this.setState({"PhotosKey": response});
}).done();
if(check) {
console.log('Data was fetched!!!!!');
check();
}
else {
console.log("Data was not fetched!");
var Data = axios.get('http://jsonplaceholder.typicode.com/photos').
then(response => this.setState({ photos: response.data })).
catch((error)=> console.warn("fetch Error: ", error));
}
}
Thanks in advance!

async componentDidMount() {
const photoStorage = await AsyncStorage.getItem('GalleryPhotos')
if(photoStorage) {
try {
const photoResp = await axios.get('http://jsonplaceholder.typicode.com/photos')
const photoData = await JSON.stringify(photoResp.data)
await AsyncStorage.setItem('GalleryPhotos', photoData);
} catch(e) {
console.warn("fetch Error: ", error)
}
.then(response => this.setState({ photos: response.data }))
}
}
later
getPhotos = async()=> {
try {
photos = JSON.parse(await AsyncStorage.getItem('GalleryPhotos'));
}
catch (error) {
console.error(error);
}
}

The approach from Subramanya is basically all you need to get started, I'm just going to introduce a state management approach with redux-persist where you can definitely appreciate when your app grows.
Redux Persist is performant, easy to implement, and easy to extend.
Let say you have your app hooked up with redux and implemented a fairly organised state tree, redux-persist stores the entire app state with AsyncStorage or any storage engine of your choice.
For instance, let's assume that your API endpoint returns a collection of photos, all you need to do is update the store, and your users can expect their data is safe and saved with redux-persist.
I have not tested all the code below
Let's define the store first,
import { AsyncStorage } from 'react-native';
import { createStore, compose, applyMiddleware, } from "redux";
import { persistStore } from "redux-persist";
import ReduxThunk from "redux-thunk";
import reducers from "../reducers"
const middleWare = [ReduxThunk]
const store = createStore(
reducers,
{},
compose(applyMiddleware(...middleWare))
)
// you can define more parameters, like blacklist or whitelist a reducer
// also, specify storage engine
persistStore(store, { storage: AsyncStorage });
export default store;
At your app's entry point,
import React, { Component } from "react";
import { Provider } from "react-redux";
import Router from "./Router";
import store from './store';
export default class App extends Component {
constructor(props) {
super(props);
}
render() {
return (
<Provider store={store}>
<Router /> // navigator
</Provider>
);
}
}
Finally, your API logic.
// action creator
export storePhoto = photos => {
return {
type: 'STORE_PHOTOS',
payload: photos
}
}
// photos reducer
import { REHYDRATE } from 'redux-persist/constants';
export default (state = {}, action) => {
switch (action.type) {
case STORE_PHOTOS:
return { ...state, photos: action.payload }
// this is where `redux-persist` handles caching
case REHYDRATE:
var incoming = action.payload;
if(incoming) return { ...state, ...incoming }
return state;
default:
return state;
}
};
To retrieve data, you will see that redux abstracts away all the excess logics and there is no more setItem, getItem because redux-persist does that automagically for your already.
import { connect } from "react-redux";
import { storePhotos } from "./actions";
class GalleryList extends Component {
async componentDidMount() {
const photos = await axios.get('http://jsonplaceholder.typicode.com/photos');
storePhoto(photos)
}
renderPhoto = ({ item }) => <GalleryDetail photo={item}/>
keyExtractor = (photo, index) => photo.id;
render () {
return (
<FlatList
data = {this.props.photos}
keyExtractor={this.keyExtractor}
renderItem={this.renderPhoto}
/>
);
}
}
// pull data from photos reducer
const mapStateToProps = ({ photos }) => {
return {
photos: photos.photos
}
}
export default connect(mapStateToProps, { storePhotos })(GalleryList);
To summarise,
Install redux-persist in you project.
Import persistStore and autoRehydrate form redux-persist.
Add autoRehydrate to your store.
Pass your store to persistStore.
Listen to the persist/REHYDRATE action on your reducer and populate state accordingly.
Hope my answer helps!

Answer
Caching the data for a specific period of time
const cacheIntervaInHours = 24
const cacheExpiryTime = new Date()
cacheExpiryTime.setHours(cacheExpiryTime.getHours() + cacheIntervalInHours)
const lastRequest = await AsyncStorage.getItem("lastRequest")
if (lastRequest == null || lastRequest > cacheExpiryTime) {
fetch(`${apiUrl}/blogPosts/recent`)
.then(async (response) => {
return await response.json()
})
.then(async (json) => {
if (!json || json.length == 0) {
throw new Error()
}
AsyncStorage.setItem("lastRequest", new Date());
return await AsyncStorage.setItem('blogPosts', JSON.stringify(json))
})
.catch(error => {
console.error(error)
})
}