new to react native expo.
running on
node.js version 16.16.0,
npm verison 8.11.0
expo version 5.4.12 (after running npm install --global expo-cli)
when initiating a new project using
expo init
(choosing blank)
I'm getting a very large project, 190MB!
Looking into the project i see that the reason for that is node_modules,
I tried to set up the env. in 2 different PCs and getting the same thing.
for some reason i cant see any discussions on it,
can someone please tell me what am i doing wrong?
Thank you
node_modules is always a really large folder. It has all the dependencies of your app including the expo and react native libaries. When you build your app for production your actual binary will be a fraction of that. My node_modules folder for a recent React Native app was about 1 GB but the actual app itself ended up only being about 50MB.
I'm currently running a detached expo project in development mode. Whenever I run expo start or npm start in the terminal I get the following logs:
$ expo start
Starting project at /Users/johncd/workspace
Expo DevTools is running at http://localhost:19002
Starting Metro Bundler on port 19001.
Tunnel ready.
Your native app is running at expb675c828acbb437095bc6218883f56bb://192.168.1.12:19000
Logs for your project will appear below. Press Ctrl+C to exit.
The expected results would include a QR code after these logs, but there is none.
When I visit the DevTools at localhost:90002 I see the metro bundler is running on LAN and a QR code is available. However, when I scan this QR code, it results in an error reading "No usable data found".
I've tried checking for a Firewall (System preferences > Privacy > Firewall) but it appears to be turned off.
I have also tried uninstalling and re-installing expo-cli as well as the project and running expo start again but to no avail.
I've tried using npm start and yarn start. I have also tried running the project on a tunnel.
I created a test project using expo init test-project and successfully ran it using expo start, so it seems this issue is only occurring on this project.
I also tried running expo start --clear to clear the cache.
None of these have worked.
Any help is appreciated!
Versions:
"expo": "^33.0.0",
"expo-constants": "^5.0.1",
"expokit": "^33.0.4",
"react": "16.8.3",
"react-native": "https://github.com/expo/react-native/archive/sdk-33.0.0.tar.gz",
"react-native-unimodules": "^0.4.2",]
Running on OSX
You need to install expo client app first from the appstore, then the qr will be readable.
You need to install Expo Go application from app store.
I didn't see anywhere a mention of what platform you're trying to use (iOS or Android) but at least with iOS I can tell you that QR codes in Expo don't really work correctly anymore. I believe Apple prevented the Expo team from being allowed to serve the bundle through the Expo app anymore. What this means for you is that the workflow you should expect is to connect your phone to the device physically using a cable and serve the bundle through USB. You can also use an emulator and move to the device when it's convenient.
Always getting white blank screen when running the app on the physical device in android case. Using react-native-navigation can't able to detect the bug please help!
I have created a fresh react-native project and integrated the react-native-navigation library into it and when I am running the app in my physical device by running the command yarn run android it runs but shows blank white screen in android. Once it runs successfully but now it won't.
run react-native start in a separate terminal and then run react-native run-android.
i recently faced two kind of white screen problem
1.always showing white screen (due to bundling..)
solutions is
react-native start
and then
react-native run-android
2.it shows white screen some particular seconds or suddenly always shows white screen in properly working app
due to app cache or traffic
solutions is
Androidmanifest.xml
android:usesCleartextTraffic="true"
If Debug JS Remotely is on then also we see the blank screen. I have recently come across this issue. So check if you are already running Debug JS Remotely. If you are running it already then just stop remote debugging. And it will work.
Running ./gradlew clean on android folder and then uninstalling the app from the phone worked for me.
In my case, was using my Phone to test and develop, and suddenly white screen issue appeared.
The app was not loading at all, no error, no code update only white screen comes up after npx react-native run-android.
My solution was to clear the phone cache as it was loading from cache.
I restarted my phone then cleared all cache and then it worked for me.
Use "react-native init" command for the creating the project as it only build react-native not expo and the other node modules for you and then build for the particular platforms for eg. in my case "react-native run-android" and it works.
There is step-by-step what I do to run app on physical android device:
Open 'android' folder from app folder in IntelliJ
Run in IntelliJ, target: USB device
After .apk finish installing, shift-right click in app folder, run PowerShell, type 'react-native run-android'
After it finish, open app on physical device, shake it to open developer menu, and hit 'Reload'
you can also hold menu button on your device to open developer menu(while app is running)
I also faced same issue in the emulator. So the way I solved it is by going into Android settings - Apps - select the app, and force stop it. Then I tried opening the app again and it worked.
Before I did this, I removed the 'build' folder under /android/app/ and re-ran. Did not work.
One thing that often resolves this problem for me is re-installing your node_modules folder and cleaning your gradle build. You can do this manually, however, if you've run into this problem once or many times, consider running a shell script to automate this process.
Create a file called clean.sh and paste this inside:
echo "Removing node modules from $1 then reinstalling..."
cd $1
rm -rf node_modules
yarn install
echo "Cleaning gradle project..."
cd android
./gradlew clean
cd ..
If using npm, change "yarn" above to "npm".
Put the file above in the parent directory of your project (if your project is located at C:\Users\your.name\projects\project1 put the clean.sh file at C:\Users\your.name\projects\).
To run the script, inside of Git Bash or your Unix terminal run this (make sure to change the name of the directory below to the parent directory of your project):
cd C:/Users/your.name/projects
./clean.sh <project-name>
Now when restarting your app, try also reset the packager's cache.
With yarn:
yarn start --reset-cache
yarn android
With npm:
npx react-native start --reset-cache
npx react-native run-android
In my case I had a metro terminal running from my previous project. closing it and running the new project again solved the issue.
Use react-native-splash-screen. I try many ways to fix this issue but it's not working and i think this is the best way.
For me my wifi was disconnected on my test device.
I had to make sure both my computer running the react packager/server and my device were connected to the same wifi network.
I have recently faced this kind of white screen problem
1.always showing white screen after Release
"npx react-native start"
and then
"npx react-native run-android"
2.it shows white screen some particular seconds or suddenly always shows the white screen in a properly working app
due to app cache or traffic and android Newer version also in some case when you are using API with HTTP instead of HTTPS
The reason is that newer android versions are more secure and they try to restrict HTTP request
solutions are
add this line in path project\android\app\src\main\androidmanifest.xml:
android:usesCleartextTraffic="true"
In my case:
1: I tried npx react-native start to run metro.
2: Then write npx react-native run-android in cmd, there was still a white blank screen.
3: I still faced the same issues, then I always comment on every single component, and automatically, I resolve the error. This is the best technique I ever used.
If you are trying to get it working on a Android device, make sure you have first tried to clear cache for the App, doesn't matter if reinstalled.
Try the other answers only after you have cleared cache.
It can not find its navigation's route. You should check the navigation.
I'm trying to run a boilerplate react-native app and the packager seems to stall out right at the beginning when the javascript bundle is requested. Eventually the iOS simulator gives up and throws Could not connect to development server.
Here is the terminal output:
[01/17/2017, 10:48:00] <START> Initializing Packager
[01/17/2017, 10:48:00] HMR Server listening on /hot
React packager ready.
[01/17/2017, 10:48:47] <START> Requesting bundle
bundle_url: /index.ios.bundle?platform=ios&dev=true&minify=false
I haven't been in react-native for a few months but I used to be able to specify whether the app should load from a bundle or just load the js directly. I would load directly when the xCode project was in debug mode or from a bundle when in release mode.
Again this is just straight boilderplate - no external packages or anything. Just using react-native init TestProj and then cd TestProj/ && react-native run-ios
I'm using the last version of react-native 0.40.0 and the expected react dependency of react#~15.4.0-rc.4.
Thanks for any help on this.
I'm not sure what the issue was but it was fixed after I restarted my computer. I also had issues getting the code to refresh once the app was loaded. That was fixed by uninstalling nodemon globally.
I have some issues with React Packager on Windows
Loading
After loading (long long wait), my application is lauching well on AVD Android. But when i change a file and i reload on my app, i see no change. I can do that 10X and no change. (I'm talking about the welcom react base app and i change index.android.js file so nothing very exotic)
Some times, the change on *.js file are detected and my app update well. When it work, it work all the time until i stop the packager. When it doesn't work, it doesn't working until i restart packager.
So for too work, i have to launch, try, launch, try, launch try until it is ok. As you can see, the loading can take 3min so it's not cool.
I tried to activate, desactivate hot reload but no change.
I don't think it's a network issue because after reboot packager, sometimes i have the old version. So i use --clear-cache option. And when i reload the app in android, i can see that packager catch the request but don't send the good version.
So i've conclued that Packager didn't detect very well the file change.
I know on Windows Watchman does not existe maybe there is a work around !!! If you have a solution for slow loading i'm ok too :-)
Can you help me ?
npm -v react-native : 2.15.1
npm -v : 2.15.1
node -v : v4.4.4
Thank you !!!
I had the same problem with nodejs 4. But when I installed nodejs 6 and make run-android init again the problem is fixed. Try to uninstall node 4 and install node 6.
After deleting .expo and node_modules folders and running yarn install changes detection started working again