I am working on a react native app, but on its native side.
If I run react-native run-android or run-ios it will first build
the native packages, to then start and complete the packager (at least for production). This process takes a long time. Is there a way to tell the script to use the latest built version of the assets, and just recompule the native binaries?
EDIT: I found out that you can add org.gradle.configureondemand=true to your gradle.properties, in order to skip bundleJsAndAssets. However, I can't find how to add the assets manually later.
you can install Webstorm IDE and then install React Native Console plugins for this.
Finally, link to the your project.
It's likely that you can see what you want
Related
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.
I would like to know if it's necessary to rebuild react native project after installing and linking libraries that includes native codes.
Yes, as react-native-link updates some native files that are under the ios/android folder, that won't be checked during a reload/hot-reload/live-reload. All those files aren't checked in your jsBundle and are compiled during a run-android or run-ios.
Of course, if you added a new dependecy to the project and linked it, and you haven't used it anywhere in your code yet, you don't need it. If you are using that dependecy, your project instance will, most likely, die.
if your react native version is below 0.60 then you have to run react-native-link after you install any react-native module. However after react-native version 0.60 and above, this is done automatically using the new "autolinking" feature added.
Read the changelog here:
https://facebook.github.io/react-native/blog/2019/07/03/version-60
However you still need to rebuild your project after you install a native module but you dont need to run the react-native-link command anymore after installing every library after react-native#0.60 and above. Just type react-native run-android
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.
I have been using react native for a couple months now. However, I really don't know the difference between the starting commands. Currently, I use npm on my project. However, I know yarn can be used. These are the commands I really don't understand the difference with:
exp start, exp ios, exp android
react-native run-ios, react-native run-android
npm start, npm ios, npm android
Which ones are better in what cases and why? Currently, I am using exp but others use react-native run-ios. I used to use npm ios.
Thank you in advance.
It might help to have an overview of the React Native architecture.
In react native, when you write, say, <View/>, it gets sent across the bridge to the native code and dynamically translated into UIView on iOS or android.view.View on Android. Every basic component in the react-native package has been implemented this way. If you want additional native functionality on both platforms, say a library which uses native map components, you will end up having to include the native libraries separately into your Android build.gradle and your iOS .xcodeproj.
The exp CLI is used to start apps built with the Expo SDK. Expo is essentially a prebuilt app with a certain set of native components already included for convenience; all you supply is your JSX; thus the recommendation to "eject" to a regular react native app if you need to use any other libraries.
react-native run-ios and run-android builds the native .app or .apk using the iOS or Android toolchains, starts the Metro Bundler, which minifies and serves the JSX and other assets such as images over to your device in debug mode (You might see something like Loading from localhost:8081).
On Android, it starts the adb server to push the APK with all the native libraries included onto your device, if you have USB debugging enabled. run-ios does the same with the .app; if you install to a simulator it has automatically configured AppDelegate.m to communicate with localhost:8081, whereas live reload over USB has to be configured manually on a physical device.
react-native start simply starts the Metro bundler, which is useful if you already have the app installed.
Commands that begin with npm are defined as scripts in your package.json file. As of RN 0.57, npm start simply calls node node_modules/react-native/local-cli/cli.js start; which is the same as running react-native start; according to the docs react-native-cli installed separately will call the locally installed version of the CLI in node_modules.
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.