In the last few years there's been lots of solution that claim to let you create "Native" mobile apps with existing Web Technologies (HTML, CSS and JS). Frameworks like React Native and NativeScript that I know.
I am a web developer and as far as I know you cannot write Android/iOS apps using JavaScript. I can kinda map in my head how HTML and CSS translates to native apps, but about JavaScript I don't understand.
Do they transform language to platform-specific language? Or do they ship a JS engine with your app to production?
Let's say I have a ReactNative project and this is part of my app:
import React from 'react';
import {Text, View} from 'react-native';
const YourApp = () => {
return (
<View
style={{
flex: 1,
justifyContent: 'center',
alignItems: 'center',
}}>
<Text onClick={() => {
const a = 2 + 2;
const b = Math.random();
doSomethingWith(a * b);
}>
Try editing me! 🎉
</Text>
</View>
);
};
export default YourApp;
In the above code, what does happen behind the curtains at framework level? For every part? (JSX part (View), those styles (CSS) and when I click on Text (JS))
Related
I have a React Native - Expo Android mobile app that we are using to send text messages out to customers to let them know when we arrive, currently using Twilio and it is expensive, I have tried many code examples to send a text message directly from the phone and they all seem to go outside the app and want to send the text message through the phone's default message app eg Messages, we want to stay in our app and send them.
My question is:
Is there a way to do this? If so how?
If not what is a cheaper solution than Twilio to send texts that will work in a React Native - Expo app?
I have been trying to find a solution now for quite awhile.
Thanks in advance for your help!
I have tried many code examples with no luck, here is an example of the code I have tried:
Here is an example of the code I am trying:
/** #format */
import { StatusBar } from "expo-status-bar";
import { StyleSheet, Text, View } from "react-native";
import { Entypo } from "#expo/vector-icons";
import Communications from "react-native-communications";
export default function App() {
return (
<View style={styles.container}>
<Text style={styles.textStyle}>SmS App</Text>
<Entypo
name="message"
size={70}
color="#202668"
onPress={() => Communications.text(
'3435447131',
'Hello'
)}
/>
<StatusBar style="auto" />
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: "#fff",
alignItems: "center",
justifyContent: "center",
},
textStyle: {
fontWeight: "bold",
fontSize: 30,
color: "#2AB4F3",
bottom: 10,
},
});
I made expo initial app
My code:
import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
import NfcManager, {NfcEvents} from 'react-native-nfc-manager';
export default function App() {
return (
<View style={styles.container}>
<Text>Open up App.js to start working on your app!</Text>
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
alignItems: 'center',
justifyContent: 'center',
},
});
When I trying to import NFC manager Im getting error: Native module cannot be null
screenshot
Google said that its error with IOS notifications, Im coding from windows VScode and cannot link push notifications, how I can solve this error? I cannot code without expo because this is only one way to simulate my app from windows on iphone as I understand
I solve it: expo not allowing additional libraries
using the snack below:
https://snack.expo.io/ry_5rCk84
I am trying to display the icon 'wifi_off' using Material Icons in my react native app (just shared this as a snack on expo for easier sharing) but this is not a recognised value for prop 'name'.
and ends up displaying a '?' for unknown icon.
I am able to use wifi-off icon using 'material-community' icon set
import * as React from 'react';
import { Text, View, StyleSheet } from 'react-native';
import { Constants } from 'expo';
import {Icon} from 'react-native-elements';
// You can import from local files
import AssetExample from './components/AssetExample';
// or any pure javascript modules available in npm
import { Card } from 'react-native-paper';
export default class App extends React.Component {
render() {
return (
<View style={styles.container}>
<Text style={styles.paragraph}>
Change code in the editor and watch it change on your phone! Save to get a shareable url.
</Text>
<Card>
<AssetExample />
</Card>
<Icon name='wifi' size={50} type='material'/>
<Icon name='wifi-off' size={50} type='material-community' />
<Icon name='wifi_off' size={50} type='material' />
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
paddingTop: Constants.statusBarHeight,
backgroundColor: '#ecf0f1',
padding: 8,
},
paragraph: {
margin: 24,
fontSize: 18,
fontWeight: 'bold',
textAlign: 'center',
},
});
react-native-elements uses react-native-vector-icons to display the icons.
react-native-vector-icons has a directory where you can check which icons are available, you can look them up by name. https://oblador.github.io/react-native-vector-icons/
If you search for all the icons that have wifi in their name you find the following result for MaterialIcons and MaterialCommunityIcons
If you search for wifi_off you will find that there are no results.
Therefore wifi_off is not available to use.
It is also worth noting that react-native-elements currently doesn't support the latest version of react-native-vector-icons, you can see that in this currently open issue.
When you are using react native elements Icon, behind the scenes it is searching in a list https://github.com/oblador/react-native-vector-icons/blob/master/glyphmaps/MaterialIcons.json, here you can find the names of the Icons that are supported and as you can see "wifi_off" is not here, maybe you can try "signal-wifi-off".
I am trying to learn the basics of react native and have started with the basic tab template. I am trying to create a social media sharing screen, where you get the list of apps and airdrop on iOS to display but unfortunately this is not working. The code I have displays an empty view and I was expecting the share dialog to appear over the top. I get the view but no sharing options.
Here is the code
`
import React from 'react';
import { View, StyleSheet } from 'react-native';
import { Share } from 'react-native';
var ActionSheetIOS = React;
export default class ShareScreen extends React.Component {
static navigationOptions = {
title: 'Share',
};
showShareActionSheet() {
ActionSheetIOS.showShareActionSheetWithOptions({
url: 'https://www.someurl.org',
});
}
render() {
return (
<View style={styles.container}>
this.showShareActionSheet();
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
paddingTop: 15,
backgroundColor: '#000000',
},
});
`
any ideas why this isn't working?
You need to wrap your this.showShareActionSheet(); with brackets to get it working.
<View style={styles.container}>
{this.showShareActionSheet()}
</View>
Otherwise it's gonna be considered as plain text and not as an instruction
You can use this package https://www.npmjs.com/package/react-native-share for sharing, This package will help you share the content to WhatsApp, FB, and other social apps.
I am learning react native, so when the program crash it only shows 15:31:42: Failed building JavaScript bundle that's all it says. So is there any file or tools i can use to look for more detail error like Eclipse or dotCMS log file or which line of my code have syntax error ?
Hope This example will help you..
import React, { Component } from 'react';
import { StyleSheet, View, Text } from 'react-native';
export default class App extends Component {
state = {
items: [],
errorMessage : 'Server Error!'//You have to set this message depends on your server response
}
render() {
return (
<View style={styles.MainContainer}>
<Text style={{ fontSize: 23 }}> { this.state.errorMessage } </Text>
</View>
);
}
}
const styles = StyleSheet.create({
MainContainer: {
flex: 1,
paddingTop: 20,
alignItems: 'center',
marginTop: 50,
justifyContent: 'center'
}
});
For development simply use console.log and debug while remote debugging is enabled. For production you can use Fabric, i love it. For more information about debugging follow the docs
You can use Chrome Developer Tools.
First open Developer Tools in Simulator. Then press Command+D keyboard shortcut. It will open the developer tools.
To debug the JavaScript code in Chrome, select "Debug JS Remotely" from the Developer Menu. This will open a new tab at http://localhost:8081/debugger-ui.
Then you can use "Inspect Element" on chrome browser. Then you can select console.
When ever there is some issue in the app, you can track it from the console in google chrome.
http://facebook.github.io/react-native/releases/0.49/docs/debugging.html#chrome-developer-tools