ReactNative, What's the benefit of using expo bare workflow? - react-native

There was create-react-native-app just like create-react-app
However I see https://github.com/react-community/create-react-native-app has been merged to expo.
Since I need native (android or ios) support, I can do either of theses
expo bare workflow
https://docs.expo.io/versions/v34.0.0/bare/exploring-bare-workflow/
react native init
https://facebook.github.io/react-native/docs/getting-started (react native cli quickstart)
What do I gain by going through expo bare workflow?

If you use Expo, you can use the module in Expo. Of course, Expo needs to install modules for APK availability starting with SDK33. However, you do not need to link the Expo separately.
If you use Expo, it will automatically reload the code when it is refreshed and not restarted, making it easy to see the code change.
And with fast feedback, the development cycle will be faster. Because the process of communicating from simulator to native apps is still slow, build time will be increased when using Web versions that run directly into the browser, until HMR creates a basic framework for the app because it is fast and fully available with Chrome Developer tools.
Also, if you want to install a React-native module that requires a link, you can use the 'expo eject' command to eject Expo. Then you can use React-native.

Related

React Native Error - TypeError: null is not an object (evaluating '_reactNative.NativeModules.RNShare.FACEBOOK')

I'm working on react native project and I am using expo. I want to add the react-native-share package to my project, however I keep getting this error before I even add any code.
TypeError: null is not an object (evaluating '_reactNative.NativeModules.RNShare.FACEBOOK')
Now I know that expo has it's own version of the share, however you can't specify where a person can share it too, which honestly makes the feature useless. It seems to be clear that the reason I can't use this package is because I am using expo and can't install pod into the project -- due to expo reject it --. So what should I do? Any suggestions on how to work around this?
You can't normally use dependencies with native code using Expo. At least when using the classic build system (you're using it when you run expo start in the terminal to run your project). react-native-share has native code (you can check that by going to the repo and seeing if the library has ios and android folders) and therefore can't be used with "standard" Expo.
If you want to use custom native code in your project, you either need to eject from Expo to the bare workflow or - a newer option - use Expo EAS and custom dev clients. Expo EAS allows you to stay in the managed workflow and still use native modules. You might need to write something called a config plugin for some of those native dependencies you want to use, but looking at the documentation, react-native-share should be working just fine without a config plugin.
So: Either eject to the Expo bare workflow, or use Expo EAS and custom dev clients to use native dependencies with the Expo managed workflow. Do note however that you need at least Expo SDK 41 to use EAS and custom development clients.
To learn more about migrating from the classic build system to EAS, see Expo's guide / documentation.

How to get device Id in expo react native app

I am implementing API to connect app with server. I have to use deviceId there. As mentioned in here we can use third party library 'react-native-device-info'. But when I am using it I am getting errors as attached screenshots. As per error it's saying to do linking but as I am using react version 0.62, so autolinking is there. So What can be issue? It took too much time to search it but till now I didn't get a proper solution.
react-native-device-info library wont work in Expo , since it requires linking of native modules hence the error.It will only work in pure react native apps.
You can check this by expo itself : expo-device
hopeit helps.feel free for doubts
You can use react-native-device-info even in Expo projects. You need to replace Expo Go with a custom build that has react-native-device-info library baked in.
By default, Expo Go used on Android, iPhone Emulators implies managed workflow (aka only expo-* modules are being used). However, using any pure react-native-* libraries falls under bare workflow, so you cannot use Expo Go - the error you see is from Expo Go, not your app.
Build your custom Expo app with expo-dev-client, react-native-device-info libraries included, and install that on your emulators. This needs to be done once when you add a react-native-* library.
Now continue to add code to your project that uses features from react-native-device-info.
npx expo start --dev-client and choose your emulator. Your custom build will be launched and you can make live changes as always like in Expo Go.
Do check out the section on Development Builds from Expo. Needless to say, I have successfully used react-native-device-info on my Expo project, because expo-device cannot provide what I needed.

Ejected expo react native app requires expo?

I created a RN with create-react-native-app, and I have now decided to eject. It didn't work initially, and required some packages to be installed (#babel/...), but now, it complains that Module 'expo' does not exist in the Haste module map.
Why does it still require expo, now that it has been ejected? Or have I misunderstood what ejection does?
N.B. during the ejection I chose the option to eject to an RN app, not to ExpoKit. This is on iOS, currently.
When ejecting expo app you'll be asked about using expo-kit or just react-native and it's up to you to choose, plus Module 'expo' does not exist in the Haste module map means you still using expo in your code so double check your code to be sure that you're not importing expo anywhere and try again.
TL;DR
Ejected expo react native app requires expo? the short answer is no.
when using expo app you have the ability to build your app using the expo server so you don't have to have Android Studio or XCode installed all you have to do is $ expo build:[android|ios] and download your built package after the build process is done also you can run your app using expo client app on Android and Ios but once ejecting you'll lose the ability of using expo server as your build environment instead you have to use Android Studio or XCode, but the main difference here is when you choose expo-kit you still have the ability of using expo client to run your app and you still have the ability to use expo modules inside your code but when you choose react-native you can't use expo client instead you have to use the native tools, anyway in all cases once you eject your project you have to build it yourself and you can't undo this step.
Sidenote
You can build very powerful apps using only JavaScript without any need to eject especially when using `expo SDK 31+, I'm working on an app now with features like detecting location, live maps, social login and chat and I don't need to eject it at all.
Please take a look here and here
Update:
One last thing you have to remember is that when using expo or expo-kit you can keep developing ios app on any OS but when using react-native you can't do this you MUST have a mac.

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.

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.