Managed Workflow Fundamentals. Bare Workflow. API Reference. Development and Production Mode Your project will always run in one of two modes: development or production. By default, running your project locally with expo start runs it in development mode, whereas a published project via expo publishor any standalone apps, will run in production mode.
Production mode minifies your code and better represents the performance your app will have on end users' devices. Development mode includes useful warnings and gives you access to tools that make development and debugging easier.
This comes at a cost: your app runs slower in development mode. When you switch it, just close and re-open your app for the change to take effect.
Any time you are testing the performance of your app, be sure to disable development mode. To enable development mode, make sure the "Production mode" switch is turned off:. In the terminal with your project running in Expo CLI initiate this with expo startpress p to toggle production mode. Showing the Developer Menu.
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The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. When you add some library into your project. This problem also occur for me when i try to add some navigator library into my react native project it happens then Learn more.
Ask Question. Asked 2 years, 5 months ago. Active 1 month ago. Viewed 35k times. NelsonGon 9, 5 5 gold badges 17 17 silver badges 39 39 bronze badges. Ansyori Ansyori 2, 2 2 gold badges 24 24 silver badges 36 36 bronze badges. Not a solution to your problem, but it seems like there is a problem with expo's auth system: twitter. Where do I find the actual log file? Active Oldest Votes.
Daniel Neal Daniel Neal 3, 1 1 gold badge 13 13 silver badges 30 30 bronze badges. Just simply put the following commands in Windows os in sequence it will definitely work.
David Buck 2, 10 10 gold badges 17 17 silver badges 26 26 bronze badges. Rahul Patel Rahul Patel 2 2 silver badges 9 9 bronze badges. Yes, Thanks rahulpatel it's working fine. Thank again for your contribution. Thank you for adding Mac os Instruction. Idan Idan 1, 6 6 silver badges 21 21 bronze badges. This issue arises with the latest version on node which in my case is Saif Khan Saif Khan 3 3 silver badges 14 14 bronze badges. MY problem was solve by running npm install inside current Project directory if it still not work than update expo to new latest version and restart project again.
This works. Jaywant Narwade Jaywant Narwade 1 1 silver badge 4 4 bronze badges. Giancarlo G Giancarlo G 11 1 1 bronze badge. Omar bakhsh Omar bakhsh 75 1 1 silver badge 6 6 bronze badges. Ravinsan Ravinsan 1 4 4 bronze badges. Keshav Gera Keshav Gera 5, 1 1 gold badge 33 33 silver badges 34 34 bronze badges.
The Overflow Blog. Q2 Community Roadmap. The Unfriendly Robot: Automatically flagging unwelcoming comments.Although I really love Vue, the NativeScript implementation just seemed buggy and lacking in documentation. There were a couple of hiccups along the way, namely acquainting myself with all the deployment processes for the App Store, but overall I really like Expo and React Native. All in all, I think React Native and Expo are a solid choice for doing cross-platform development of mobile applications.
There have been a few minor shortcomings — namely the wallet API for iOS — that do not have a plug-and-play solution. If I were in a position that I needed those native components the cool thing about React Native is you can write your own components in their respective native language, in this case I could have written a component in Swift to do what I wanted if I was truly determined.
Naturally then as part of the development process, I came to a point where I wanted to debug my application. Once again this was fairly easy and I was successfully debugging after getting past a few very minor molehills. One will launch the iOS simulator, the other will launch the Android simulator. Click on the bug tab in the left navigation toolbar in VSCode.Отладка(Debug) - React Native - Урок 16 - Level 0
Now click on the gear icon next to the drop-down at the top of the debug window. This will open up a JSON file where the different debug settings can be configured. This is where I hit a little snag in the process. Out of box React Native Tools wants to connect to the metro bundler process on portbut expo seems to run it on by default.
This will tell React Native Tools to use port when connecting to the bundler process for debugging. Make sure the metro bundler process is running in your terminal first what we started by running npm run ios.
Click the green arrow. This will attach VSCode to the metro bundler process in the terminal we started and allow us to bridge data from the simulator to the debugger. The final step in the process is to return to the simulator and enable remote JS debugging. Click to the left of the line number where you want to add a breakpoint and a red dot will appear.
If you have any questions or feedback feel free to drop me a line in the comments. Happy coding! Looking to grow your business with the right technology? Sign in. Brad Zasada Follow. Highland Solutions A CX and digital agency with a fierce commitment to keeping…. Thanks to Bridgett Colling. Software Developer. Highland Solutions Follow.Managed Workflow Fundamentals.
Bare Workflow. API Reference. Debugging Contrary to popular belief, there are sometimes better ways to debug than putting console. There are plenty of tools and libraries that can improve the debugging experience. This document will explain how to use some of the most commonly useful tools. Errors and warnings. In development it won't be long before you encounter a "Redbox" error or "Yellowbox" warning.
Redbox errors will show when a fatal error has occurred that prevents your app from running. Warnings will show to let you know of a possible issue that you should probably look into before shipping your app.
You can also create warnings and errors on your own with console. Another way to trigger the redbox is to throw an error and not catch it: throw Error "Error message". Redbox errors and stack traces. When you encounter an error during development, you will be shown the error message, as well as the "stacktrace," which is a report of the recent calls your application made or was making when it crashed.
This stacktrace is shown both in your terminal and in the Expo client app. This stacktrace is extremely valuable since it gives you the location the error comes from.
For example, in the following clip we know that the error came from the file LinksScreen. Developer menu. This menu gives you access to several functions which are useful for debugging. The way you open it is a bit different depending on where you're running the Expo client:.
Android Device: Shake the device vertically a little bit, or run adb shell input keyevent 82 in your terminal window if your device is connected via USB.Managed Workflow Fundamentals.
Bare Workflow. API Reference. Viewing Logs Writing to the logs in an Expo app works just like in the browser: use console.
The fastest way to build an app
Note: we don't currently support console. Recommended: View logs with Expo tools. When you open an app that is being served from Expo CLI, the app will send logs over to the server and make them conveniently available to you.
This means that you don't need to even have your device connected to your computer to see the logs -- in fact, if someone opens the app from the other side of the world you can still see your app's logs from their device. Viewing logs with Expo CLI. If you use our command line tool Expo CLI, bundler logs and app logs will both automatically stream as long as your project is running.
Expo Dev Tools logs. Expo Dev Tools allows you to display many log windows side by side and to choose which logs to view from bundler logs and app logs from each connected device. Optional: Manually access device logs. While it's usually not necessary, if you want to see logs for everything happening on your device, even the logs from other apps and the OS itself, you can use one of the following approaches.
View logs for your iPhone or iPad. View logs for an iOS simulator. Option 1: Use GUI log. Option 2: Open it in terminal. View logs from Android device or emulator. The following instructions apply to any OS that supports Android development. Ensure that USB debugging is enabled on your device not necessary for emulator.Android client for viewing projects.
Build service gives you app-store ready binaries and handles certificates, no need for you to touch Xcode or Android Studio. Over-the-air updates let you update your app at any time without the hassle and delays of submitting to the store. Snack allows you to run code in the browser in a matter of seconds. No downloads required. This guide is intended to give developers who have already used React Native a quick outline on some of the key concepts, resources, and differences they will encounter when using Expo.
Get started. Start your first project. Try Expo in the browser Snack allows you to run code in the browser in a matter of seconds. Docs: Already used React Native? See more. Need Help? Resources to get help with Expo. Get started in minutes Learn how.Managed Workflow Fundamentals. Bare Workflow.
API Reference. Android Studio Emulator If you don't have an Android device available to test with, we recommend using the default emulator that comes with Android Studio. If you run into any problems setting it up, follow the steps in this guide. Step 1: Set up Android Studio's tools. Make sure that you can run adb from your terminal. Step 2: Set up a virtual device. Choose the type of hardware you'd like to emulate. We recommend testing against a variety of devices, but if you're unsure where to start, the newest device in the Pixel line could be a good choice.
Select an OS version to load on the emulator probably one of the system images in the "Recommended" taband download the image. Change any other settings you'd like, and press "Finish" to create the virtual device. Multiple adb versions. Having multiple adb versions on your system can result in the error adb server version xx doesn't match this client xx ; killing This is because the adb version on your system is different from the adb version on the android sdk platform-tools.
Open the terminal and check the adb version on the system:.