Expo - Build in local - react-native

I have a question and I didn't find a clear answer.
It's possible to build android and iOS app in local ?
We can build the application with expo build:android and expo build:ios but these commands need an account and send the source code in server of expo.
I see it's possible to eject the app and folder android and iOS are created but after that I keep the possibility to develop with expo ? If I modify a javascript code I can recreate again the android and iOS folder ? or I need to develop in native code ?
Thank you for your answers !

As far as I understand your question, If you eject the app, you can't develop with expo. But, you can keep editing in javascript. There is no necessity to develop in native code.

Related

Building expo app is not updating the app in store

I used to run expo build:android (or ios) to build and publish my react-native application.
The app in the app store automatically updated doing this.
Since I updated my expo version to 38.0.8 it doesn't seem to be working anymore?
Does anyone know what's the problem here?
Generally you have to run
expo build:ios(or android)
to generate an expo build, and then run
expo upload:ios(or android)
to upload to the App Store or Google Play Store

Why is that we cannot install native libraries on Expo? (that requires linking)

I am a newbie and learned react-native expo. I am curious why we can't use any native library with Expo.
For example, if I want to use filesystem on expo I just cant use it, I know expo has it's own file system but I want to use another library but that library requires linking so it is not working in expo. Why is that?
I have tried everything.
This is the library that I want to use ==> https://github.com/itinance/react-native-fs
It requires command : react-native link react-native-fs
How do I do it?
You first have to understand the difference between react-native cli & expo
Please read this documentation to understand the difference
React Native expo uses their own servers to compile your javascript into java and return APK file as a complete APP, and that is the reason you do not need android SDKs or android studio environment on your PC when you are using expo
but when you are using react-native cli you do need the android studio environment such as SDKs, because when you are using cli , it compiles the code using that android studio sdk/environment that you made in your PC that is why you do not need a third party server like expo do.
and thats the reason you get android files right in your react-native project and due to which you can add native modules to it.
However you also have the option to use expo-eject, You can read more about expo-eject in this documentation
Thank You!, Have a great day & welcome to stackoverflow community!.

Expo React-Native App doesn't work when run as a standalone APK

My Expo-based React Native App works without a problem when run in the Expo tool but gave the following errors when built as an APK to be installed and run standalone.
A series of white screens keep flipping before the blue screen comes up.
Here are my App.JSON and Package.JSON files
Package.json
App.json
And here are the screen capturing the error message.
Actually there are two ways to create a React Native application
create-react-native-app (CRNA)
react-native init
As you stated in comment section, You created your project using CRNA
CRNA will gave you some form of solid project structure, which is really useful for beginners to get started with react native, you code the app with pure javascript and the app will work inside Expo.
Now if you want to take build and run as a standalone apk for android,
There are two methods
You can run command: exp publish:android
You can eject your app from expo
Dont use exp publish for standalone apks,
You can use second method:
To eject your app:
First if you dont use any expo apis inside your apps, it is very easy to eject and build as a stand alone apk.
just do yarn eject
This will gave you some instructions and follow that.
After that your CRNA project structure will be converted into react-native init project structure, now you will be able to see "Android" and "iOS" folders inside your application
To take build Run: connect your phone with USB debugging ON and react-native run android.
That's all.
Solved my own problem. The 'eth-lightwallet' library works perfectly within the Expo development tool but when I build into an APK, it just made the white screen turns up with no meaningful error messages.
The solution is to replace it with a pure web3js implementation.
This may be useful if you are developing a mobile app for Ethereum.

Converting project to react native init

Firstly I created my project with create-react-native-app and I'm developing my app with npm start and I have expo installed on my emulator. How can I convert these project into react native init, I don't want to use expo anymore...I don't neeed any api-es from them...
Thank you
The best resource for this is in the create-react-native-app repository. Try having a look here to get started.
The short answer is to use npm run eject
If you have experience generating signed APKs for Android and code signing with iOS then you shouldn't run into too much trouble.
If you don't, then take the time to go through the Android docs and also this guide should help you get up on running on iOS as well.
Good luck!
Instead of creating your project using the command create-react-native-app, you may create a react native project by following "Building Projects with Native Code" of the getting start guide: https://facebook.github.io/react-native/docs/getting-started.html.
Here you will find out how to:
1. Set up the environment.
2. Installation of phone emulator.
3. Connection of your phone via USB for testing.
4. Create a project using the react-native init command.

Can I not use Expo (cloud service) at all using React Native

I have build an app using react native(detached) but the thing is I would want to completely get rid of Expo. The reason is, what if one day EXPO service get shut down or no more supported.
So in this case I would not want the app to be affected.
Currently I need to publish my app thru ExpoKit to see the latest changes, how would I build my android app so it would not have any reference to Expo but still be able to work properly
Currently this is how I understand how the react native and expo works: first u build ur app using react native code and then a bundle.js is generated somewhere on cloud(EXPO) using publish command so the app communicate with that bundle.js.
Note I am not using any feature from Expo so why would I need Expo in this case?
Edited: If I am detaching my app from expo, I mean why would I still need Expo? Can't I just build the app and run the app without expo at all?
You can build your whole application without using expo, just follow the steps from facebook documentation in "Building Projects with Native Code" tab.
or
you can run "npm run eject" in your project root directory folder.
After this, you can build your appliaction using react-native cli commands, like
react-native run-android.
edited :--
For building apk for production, you can follow steps given in facebook documentation as generating signed apk and for released IPA for iOS yo can follow building your app for production for IOS.