How to catch breakpoints in vscode in React Native cli project?
Background:
Few days ago I started learning react native.
I was able to catch breakpoints in vscode in my expo projects. With some settings but still.
But when I started new cli project I lost this comfort.
Notes:
Debug is activated on virtual android machine
react native tools
package is installed
Attach to packager as the default debug
configuration (During launch.json creation I was missing „React
native“ environment option. Do not know why.)
I run my apps normally with two commands
npm start
npx react-native run-android
Thank you for your time.
Related
I am new to react-native or you can say new to React and I am working on react-native navigation I have installed all the required libraries as instructed in https://reactnavigation.org/docs/getting-started but when I am running my code it is giving an error as '#react-navigation/native could not be found within the project or in this directories.' What should I do is there any way to get started with my code? Help me
If you have installed your app following the react native cli guide you might want to try running
gradle clean
in your android folder und then try to run your app in the emulator again.
On my first steps with react native I stumpled upon the same issue. :-)
I want to run my React Native app in the iOS emulator. Here is what I done so far:
I installed XCode, along with its command line tools, and can bring up the emulator without issue.
I created an empty React Native app using the Expo CLI, per the instructions here. https://facebook.github.io/react-native/docs/getting-started. I am running on Node v10.0.0 on a Mac.
Afterwards I install all the necessary dependencies.
I then run "sudo npm run ios". This fires up the Metro Bundler as well as the iOS simulator. The Simulator loads up after about 5 minutes of waiting, but my app does not start up.
What am I missing here?
I should note that I prefer to stick with Expo, so I'd prefer not to have to eject.
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.
Is there any good document/video that talks about how to debug a react-native application using Nuclide.
Am a newbie. Its my first time app development and first time with React.
I did create the project using react-native init. I don't think i found a BUCK file for me to run and debug my app. I also don't see to get how to view the errors in my JS file. I have to run the simulator to see. I run it using react-native run-ios.
I tried Nuclide->React Native->Start Debugging. Not sure what this is supposed to do.
Sorry if these questions sound silly.
According to this instruction you should:
From the command Palette (Cmd-Shift-P) choose "Nuclide React Native: Start Packager" to start the React Native Server.
Ensure that you are in the root directory of the React Native project, then run the application from the command-line: "$ react-native run-ios" (or choose other existing simulator, for example react-native run-ios --simulator="iPhone4s").
After starting the server, you can prime the React Native Debugger for when the application begins running. From the command Palette (Cmd-Shift-P), launch "Nuclide React Native: Start Debugging".
From the Simulator press Cmd-D (Ctrl-D on Linux). This will bring up the debug options for your application. Select "Debug JS Remotely.
...After you enable debugging from the simulated application, Nuclide will attach to that debugging process automatically, since we primed the Debugger above.
Debug JS in Nuclide is now an option in the dev menu added in React Native version 0.52 December 2017 release.
See This