How do you debug react-native when it is running on device ?
Figured our React Native debugging for Android. Steps to for someone struggling with this -
Launch your RN App
Shake device
Select "Dev Settings"
Select "Debug server host & port for device" Put in your system's IP address.
Shake device
Select "Debug JS remotely"
Chrome will open a new tab with the address "http://localhost:8081/debugger-ui"
If this doesn't happen, check your port and open a new tab and enter the above address with your port number.
Open #Chrome DevTools (Cmd+Alt+I on #MacOSX)
Select the Console Tab
Shake Device
Select "Reload"
View all your console logs or use "debugger;" in your JS for breakpoint debugging.
You have two options:
Debug remotely
iOS: Cmd + ctrl + z to open menu and select "Debug remotely"
Android: Cmd + M to open menu and select "Debug remotely"
Or run one of these commands:
react-native log-ios
react-native log-android
There are little hack in here for IOS.
In XCode open AppDelegate.m from project folder, comment the line with jsCodeLocation declaration and add near it something like this:
jsCodeLocation = [NSURL URLWithString:#"http://%YOUR_PC_IP%:8081/index.ios.bundle?platform=ios&dev=true"];
, where %YOUR_PC_IP% is IP of your dev machine on local net.
Then open project named RCTWebSocket wich located in Libraries folder and then open from this project file RCTWebSocketProjectExecutor.m. Next, comment the line with host declaration, then add near it something like that:
host = #"%YOUR_PC_IP%";
Almost done. Run app on your device with XCode and make sure that your IPhone can see your develop machin via internet.
After it launches make sure that node server is running (command "react-native -- --start" in root project folder) and open via chrome this page: http://localhost:8081/debugger-ui . Plus, option Debug JS Remotely must be enabled in your app on your IPhone. (Shake action, then tap in opened menu Debug JS Remotely, that is it.)
Now open dev console and have happy debugging.
2 options exist:
Remote debug: this would go over network, so it can be laggy.
Run app on device (install it whilst its plugged in)
Shake device (Android devices need to be vigorously shaken)
Press settings on the dev menu, and under Debugging, press Debug server host and port for device
Enter your debug server's IP address and port (usually 8081 unless you changed your settings of the debug server), e.g. 255.255.255.255:8081. Your ip address is the local IP address that your computer has. Ensure the device is on the same network. For mac users, open System Preferences → Network → Wifi → Under Status: connected, there is an IP address, use that.
You can unplug the device
Ensure debug mode is on (Shake device vigorously again, press Debug)
Wired debug: relatively better for slow connections
Install app on phone
If android, set up port forwarding with adb reverse tcp:8081 tcp:8081 and if iOS, follow the steps from RN docs)
Enable debug on device
If you are working on Visual Studio Code then you can install React Native Tools extension (provided by Microsoft) and debug your app like any other IDE.
Read all steps in detail in my this answer.
Related
adb devices detect my physical phone but react-native run-android command open my emulator..
and whenever i put this command npx react-native run-android --deviceId=97e2bc510706 it shows error no emulator or android device connected I WILL GET THIS ERROR
if you have android studio , open your project's android folder in android studio and run in your physical device and in vs code run command npx react-native start and if you are using mobile hotspot then open your app and shake your device or long press minimize button , go to setting and in port add your ip (for example : ,196.168.0.1:8081) after ip put your port number.
hope it will work ...!
Always remember sdk path not contain any space in my case my username of computer is shrivastava ji so there is space in my username so remove space in your username or file name or change the sdk path where path have no space
am new to React native Expo I need to add some new modules on my project. "expo": "33.0.0", "react": "16.8.3", whenever I try to run my project am getting Error am not able to run the project. I tried all way to run the project like set REACT_NATIVE_PACKAGER_HOSTNAME='192.168.0.102', firewall off, allowed inbound 19000 port etc. but am getting error.
when I enter expo start -c
Your project may not work correctly until you install the correct versions of the packages.
To install the correct versions of these packages, please run: expo install [package-name ...]
Starting Metro Bundler on port 19001.
Your JavaScript transform cache is empty, rebuilding (this may take a minute).
Your native app is running at exp9c305c55e38f4d0e856f59397620314e://192.168.0.101:19000
Logs for your project will appear below. Press Ctrl+C to exit.
then my laptop and mobile is connected with same network and same IP but am getting error and i don't know the port 19000 is different from my wifi
Uncaught Error:java.net.SocketTimeoutException:failed to connect to/192.168.1.20(port 19000)from/192.168.0.102(port 49615) after 10000ms
Please give some solution for it.
It's failing because port 19000 is not open in your firewall. If you use linux OS open this port by running:
sudo ufw allow 19000/tcp
enter image description hereFirst Check are you in tunnel connection?
If you are in tunnel connection then
First : ipconfig
then : set REACT_NATIVE_PACKAGER_HOSTNAME=192.168.1.103 (IPv4 Address)
then:npm start
It worked for me. Hopefully it will help.
I resolved this by changing the network profile on the connected wifi from private to public.
Expo Error Fix
(I'm almost a newbie in React Native development) today I have started a new project in React Native 0.60 (react-native init MyApp).
After that I typed : react-native run-android to check if everything worked.
After the bundle process is finished
I can finally get my welcome screen in my connected devices
But, if I try to reload the app from my devices I get this error:
How could I address this error ?
EDIT: Thank you for your answers, anyway, I have tried all solutions you suggest but I still get the same problem. I also noticed that when i run react-native run-android Metro Bundler (open in a new cli window) seems to start but it suddenly disappear. I think the problem could be with the message 'Deprecated Gradle features were used in this build, making it incompatible with Gradle 6.0'
react-native run-android not working in new react-native version
0.60
now you can use
react-native start
OR
npm start
both command is work
Please use the following two commands and then can start the react native again.
- adb reverse tcp:8081 tcp:8081
- killall node
Then you can run the following the command.
react-native start
Now you can run your application again.
Have a good day.
You need to connect your phone to the server, follow the below steps:
[For detailed help follow this https://facebook.github.io/react-native/docs/running-on-device]
1. Open the developer menu on phone.
2. Open 'Debug server host & port for device'.
3. Type in your machine's IP address and the port of the local dev server (eg. 10.0.1.1:8081). If you have connected over wifi then this will be your computers ip address. (If you are running in your computer I think instead of ip address it would be 'localhost:8081')
4. Go back to the Dev menu and select reload.
Hope it would help.
You need to run adb reverse in the Android Studio terminal so your device can connect to the server. Open Android Studio and click on the terminal button at the bottom. In the terminal, and with your device connected to your computer, enter the command adb devices. This will list the name of the connected Android device. Copy that name. Then enter this command adb -s <device name> reverse tcp:8081 tcp:8081. When you run that command replace <device name> with the name of your device you copied from the other command.
Here is a link to an explanation in the React Native documentation
I compiled react-native on Android v4.4.2 but the problems arised:
I tried to follow this solution, but I did not how to run on Command Prompt Windows 10:
$> cd myproject
$> react-native start > /dev/null 2>&1 &
$> curl "http://localhost:8081/index.android.bundle?platform=android" -o
> "android/app/src/main/assets/index.android.bundle
$> (cd android/ && ./gradlew assembleDebug)
I tried to compile the same way on Android V6.0. Then there was no problem at all.
How to make android V4.4.2 also can be use like Android v6.0 for my first react-native
project development?
That error means your React Native app can't fetch your JS files from your localhost. You'd usually just run react-native start to serve the JS files from your packager, but Android 4.4.x cannot connect to your localhost with the default adb reverse method.
The way I run on Android 4.4.x is to manually set the device to connect to my machine via Wi-Fi (Official guide here!).
Access the React Native dev menu by shaking your device or pressing the hardware menu button (can be done with Ctrl+M or Cmd+M in a simulator, IIRC)
Go to Dev Settings
Under the Debugging section, tap "Debug server host & port for device"
Enter your machine's IP address, as well as the port through which the React Native packager is serving, e.g. "10.0.0.25:8081" (make sure your device and your machine are on the same network!)
Reload through the dev menu again (or by pressing Ctrl+R or Cmd+R in a simulator, I think)
Try running this command
adb reverse tcp:8081 tcp:8081
I'm trying to run the Google App Engine Python 2.7 Hello World program and view it in a browser via Google App Engine Launcher. I followed the install and program instructions to the letter. I copied and pasted the code in the instructions to the helloworld.py file and app.yam1 and verified that they are correct and in the directory listed as the application directory. I hit run on the launcher and it runs with no errors, although I get no sign that is has completed (orange clock symbol next to app name). I get the following from the logs:
Running dev_appserver with the following flags: --skip_sdk_update_check=yes --port=8080 --admin_port=8000 Python command: /opt/local/bin/python2.7
When I try to open in the browser via the GAE Launcher, the 'browse' icon is grayed out and the browser won't open. I tried opening localhost:8080 in Firefox and Chrome as the tutorial suggests, but I get unable to connect errors from both.
How can I view Hello World in a browser? Is there some configuration I need to make on my machine?
I had the same problem. This seemed to fix it:
cd to google_appengine, run
python dev_appserver.py --port=8080 --host=127.0.0.1 /path/to/application
at this point there is a prompt to allow updates on running, I said Yes.
At this point the app was running as it should, also when I quit this and went in using the launcher again, that worked too.
I have to manually start python and make it point to my app folder, for instance in a command line window on Windows I am using python. I installed python in C:\Python27 and my sample app is in c:\GoogleApps\guestbook
C:\Python27>dev_appserver.py c:\GoogleApps\guestbook
and then I can start my app in the Google App Engine Launcher and hit localhost 8080
How about specifying --host argument? You can find it at the bottom of following doc.
https://developers.google.com/appengine/docs/python/tools/devserver
This might be a little late. But still someone might find it useful.
When ever you go and try changing the port number from 8080 to something else, it will not get updated. So the best option is:
Go to your user directory: eg: C:\Username
There will be a Google folder. Go inside
Open the file google_appengine_projects.ini
Change your port number from 8080 to whatever you like 8081
Save it and close the file.
Launch the GAE Launcher again and you will find the changes reflected and the app runs without issues.
7: Access the application using: http://localhost:NewPort/
This can be used to change ports both run port and admin port for your individual projects running locally.
Hope this helps!
The 8080 portion of your url is a port number. Firefox disables visiting url's of other ports by default. You have to enable them by doing the following: http://blog.christoffer.me/post/2012-02-20-how-to-remove-firefoxs-this-address-is-restricted/
Paraphrasing that website:
Open firefox and visit about:conf
In the Filter box, type in network.security.ports.banned.override
If you can't find such a preference, right click to open up the pop-up menu and pick New and then String
As preference name type network.security.ports.banned.override and 8080 as the value.
Done!
It's likely if this continues to not work that your browser is behaving properly (8080 is a fairly standard port). That means that its a problem with the server and we'd have to do some more debugging.