After I updated my Dart extension in VS Code, it doesn't automatically hot-reload my Flutter codes even though I've turned on autosave. Does anyone have an idea about how to solve it?
If you using VS Code, Go to the Settings > Extensions > Dart & Flutter
Then select always in Flutter Hot Reload On Save
Congrats 🥳 Your problem is solved.
PFA screenshot here
Run the flutter doctor command and make sure that flutter is installed properly on your machine.
Which channel are you running on? Make sure that you run on the stable channel, as long as it does not give you any compile time issues.
If the flutter doctor works, then make sure that, if you are running on iOS (Physical Device), that you have bonjour service enabled. This is required in order to make debugging work on physical devices (for iOS 14+). Please also make sure that you add -v command to the end of your deploy function, to increase the log verbosity.
Otherwise you can just deploy to the simulator.
If you are running on Android, there should not be any issues, unless there is a problem with the logcat. In this case you can try to go to android Studio and reboot the ADB (Android Debug Bridge), in which case the machine will try to reattach a debuggable process to your device. If it's still not working, then try another device. If that's not working, then add the -v command, I mentioned earlier, about log verbosity.
Post an update on your issue, once you have tried all of these suggestions.
[EDIT]
Please make sure that hot reload is enabled on the vscode settings.
Go to Settings > Search > Hot Reload, and make sure it's enabled for both Auto Save & Restart.
Please take a look at this image below:
[EDIT ONCE AGAIN]
If you look at the flutter documentation (https://flutter.dev/docs/development/tools/hot-reload) it says, that to run a flutter hot reload, you have to follow these steps:
Run the app from a supported Flutter editor or a terminal window.
Either a physical or virtual device can be the target. Only Flutter
apps in debug mode can be hot reloaded. Modify one of the Dart files
in your project. Most types of code changes can be hot reloaded; for a
list of changes that require a hot restart, see Special cases. If
you’re working in an IDE/editor that supports Flutter’s IDE tools,
select Save All (cmd-s/ctrl-s), or click the hot reload button on the
toolbar.
Make sure that you follow all the steps in the documentation, then let's talk on this post again (https://flutter.dev/docs/development/tools/hot-reload)
Asked and answered over here: Flutter doesn't hot reload on autosave in VSCode. In short, it is working as designed.
The "hot reload on save" feature was intended to run when the user specifically pressed save so they had some control over when it occurred. Some users experienced issues where autosave would cause it to fire when they didn't want it to, so this "bug" was recently fixed.
It turns out that for many users, hot-reload-on-autosave worked fine, so the next version of the Dart extension will include a setting to allow you to re-enable that.
"dart.flutterHotReloadOnSave": "always"
For VS Code Go to 'File' -> 'Auto Save' make sure you have "check" Auto Save.
If you’re running the app at the command line using
flutter run
command, enter r in the terminal window to hot reload.
Try to run by clicking Run button worked in my case.
Like this
How does one debug their React code with React Native while the app is running in app simulator?
Mac: Cmd+M
Windows and Linux: Ctrl+M
Use the appropriate hotkey above from within the Simulator. It'll popup Chrome and from there you can use the Developer Tools.
Edit:
This is now linked in the help docs.
Debugging React Native Apps
To debug the javascript code of your react app do the following:
Run your application in the iOS simulator.
Press Command + D and a webpage should open up at http://localhost:8081/debugger-ui. (Chrome only for now) or use the Shake Gesture
Enable Pause On Caught Exceptions for a better debugging experience.
Press Command + Option + I to open the Chrome Developer tools, or open it via View -> Developer -> Developer Tools.
You should now be able to debug as you normally would.
Optional
Install the React Developer Tools extension for Google Chrome. This will allow you to navigate the view hierarchy if you select the React tab when the developer tools are open.
Live Reload
To activate Live Reload do the following:
Run your application in the iOS simulator.
Press Control + Command + Z.
You will now see the Enable/Disable Live Reload, Reload and Enable/Disable Debugging options.
For an Android App, if you're using Genymotion you can toggle the menu by pressing CMD + m, but you may have to enable it in the menu by doing this.
Untick widget
Enable it by CMD + m click on debug in chrome
if you want to debug using android device on Windows just open a command prompt then type ( make sure your adb working properly)
adb shell input keyevent 82
it will prompt a screen like the image
then select
debug JS Remotely
it will automatically open a new window.then open inspect element or press F12 for console.
In addition to the other answers. You can debug react-native using the debugger statement
example:
debugger; //breaks execution
Your chrome dev tools must be open for this to work
cmd ⌘ + D oddly didn't work for me. Pressing ctrl + cmd ⌘ + Z in the iOS simulator did kick off the debugging browser window for me.
This is the screen that pops up:
More details here.
Try this program: https://github.com/jhen0409/react-native-debugger
Works on: windows, osx and linux.
It supports: react native and redux
You can also inspect the virtual component tree and modify styles that are reflected in the app.
Debugging react-native 0.40.0 on Debian 8 (Jessie) can be done by navigating to http://localhost:8081/debugger-ui in Chromium or Firebug while your app is running in the android simulator. To access the in-app developer menu, run the following command in another terminal window, as pointed out here:
adb shell input keyevent 82
I don't have enough reputation to comment on the previous answers which are great. :)
Here are some of the ways how I am debugging when developing react-native app.
Live reloading
react-native makes it super easy to see your changes with the ⌘ + R keys or even just enable live reload and watchman will "refresh" the simulator with the latest changes. If you get an error, you can get a clue from the line number from that red screen. A couple of undo will get you back to working state and start again.
console.log('yeah, seriously.')
I find myself prefer letting the program run and logging some informations than adding a debugger break point. (tough debugger is useful when trying to work with external packages/libraries and it comes with autocompletion, so you know what other methods you can utilise.)
Enable Chrome Debugging with debugger; break point in your program.
Well it depends on the type of errors you encountered and your preferences of how to debug. For most of the undefined is not an object (evaluating 'something.something'), method 1 and 2 will be good enough for me.
Whereas dealing with external libraries or packages written by other developers will require more effort to debug hence a good tool like Chrome Debugging
Sometimes it is coming from the react-native platform itself so googling for react-native issues will definitely helps.
hope this helps someone out there.
React Native 0.62 Released - The Official solution is Flipper 🚀
Flipper is Android & iOS Mobile debugging tools without using debug mode in react native.
Since RN 0.62 (See this link), Flipper is initialized with default project.
Flipper has a few of plugins for debugging. The plugins include Layout, Network, Shared preferences
The greatest benefit of Flipper is not also many plugins but you can see Android / iOS device console debugging easily too.
The Flipper alert you about crash or network rejection too.
Layout plugin includes accessibility mode and target mode.
You can also see raw network request / response in your Application.
Instead of Cmd+M, for Android Emulator Press F10 in Windows. The emulator starts to show all the react-native debug options.
For Android: Ctrl + M (emulator) or Shake the phone (In Device) to reveal menu.
For iOS: Cmd + D or Shake the Phone to reveal menu
Make sure you have chrome.
On the revealed menu select Debug JS Remotely Option.
Chrome will be opened automatically at localhost:8081/debugger-ui. You can also manually go to debugger with this link.
There reveal console and you can see logs being noted.
adb logcat *:S ReactNative:V ReactNativeJS:V
run this in terminal for android log.
If you are using Microsoft Visual Code , then install React Native Tools extension. Then you can add break points simply by clicking on the desired line number.
Follow these steps to setup and debug app :
Dont forget to enable Debug JS Remotely in emulator if you using it.
To me the best way to debug on React-Native is by using "Reactotron".
Install Reactotron then add these to your package.json:
"reactotron-apisauce": "^1.1.2",
"reactotron-react-native-under-37": "^1.1.2",
"reactotron-redux": "^1.1.2",
now, it just the matter of logging in your code.
e.g.: console.tron.log('debug')
Run your app in simulator - react-native run-ios
Press ctrl + d and click on Debug JS Remotely
webpage should open up at http://localhost:8081/debugger-ui , if not type the URL and go to this link in Chrome
Right click on the page and click Inspect and it should open the developer tools for chrome
Go to the sources in the top menu and find your js class file in the right hand side file explorer
You can put breakpoints to the view and debug the code in there as you can see in the image.
If you want to enable debugging by default:
import { NativeModules } from 'react-native';
if (__DEV__) {
NativeModules.DevSettings.setIsDebuggingRemotely(true)
}
To get this working on Android:
npm install --save react-native-devsettings-android
react-native link react-native-devsettings-android
Reference: Launch a React Native app with “Debug JS Remotely” enabled by default
First in your ios simulator, if you press [command + D] key then you can see this screen.
Then click Debug JS remotely button.
After you might see React Native Debugger page like this.
And then open your inspector[f12], and go to console tab debug it! :)
By default, my ios simulator wasn't picking up the keystrokes which is why cmd-D didn't work. I had to turn on the settings for the keyboard using simulator's menu:
Hardware > Keyboard > Connect Keyboard
Now cmd-D launches chrome debugging.
For android app .Press Ctrl+M select debug js remotely it will open a new window in chrome with url http://localhost:8081/debugger-ui. You can now debug the app in chrome browser
Having a space in the file path prevents the Cmd+D from working. I moved my project to a location without a space and I finally got the Chrome debugger to work. Seems like a bug.
You can use Safari to debug the iOS version of your app without having to enable "Debug JS Remotely", Just follow the following steps:
1. Enable Develop menu in Safari: Preferences → Advanced → Select "Show Develop menu in menu bar"
2. Select your app's JSContext: Develop → {Your Simulator} → Automatically Show Web Inspector for JS JSContext
3. Safari's Web Inspector should open which has a Console and a Debugger
Very simple just two commands
For IOS $ react-native log-ios
For Android $ react-native log-android
If you are using emulator use Ctrl+M & simulator Cmd+D
Click on the - Debug js remotely
Google Chrome go to console
Assuming you want to show this menu on Android emulator
Then, try ⌘+m to pop up this dev settings dialog on Android emulator on a Mac.
If it doesn't show then go to AVD > (click the pen to edit your emulator configuration) > advanced settings > check the enable keyboard input box.
And then retry ⌘+m.
If it doesn't show still then go to the running emulator settings and on the Send keyboard shortcuts to combobox/dropdown then select the Emulator controls (default) option.
And then retry ⌘+m.
I hope this helps, it worked for me.
If you're using Redux, I highly recommend React Native Debugger. It includes Chrome devtools, but also has Redux devtools and React devtools.
Redux Devtools: This allows you to view your actions, and step back and forth through them. It also allows you to view your redux store and has a feature to automatically diff the previous state with the updated state for each action, so you can see that as you step back and forth through a series of actions.
React Devtools: This allows you to inspect a certain component, namely all of it's props as well as it's component state. If you have a piece of the component state which is a boolean, it lets you click it to toggle it and see how your app reacts when it changes. Great feature.
Chrome Devtools Allows you to see all your console outputs, use breakpoints, pause on debugger; etc. Standard debugging features. If you right click the area where your actions are listed in Redux Devtools and select 'Allow Network Inspect', you can then inspect your API calls in the network tab of Chrome Devtools which is sweet.
In conclusion having these all in one place is fantastic! If you don't need one of them you can toggle it on/off. Get React Native Debugger and enjoy life.
In React-Native debugging is much easier.
To debug in IOS use
cmd + d
ctrl + cmd + z ( For simulator )
To debug in android
Shake device with touch ( Make sure your developer option is enable )
This is the alternate way to use react native debugger application.
you can download application using below link it's very good application for managing redux store along with the source code.
react-native-debugger
as well now a days you may directly use below link for help you out.
chrome-developer-tools
Step 1:
Place debugger where ever you want to stop script, like:
async saveItem(item, selectedValue) {
debugger
try {
await AsyncStorage.setItem(item, selectedValue);
}
catch (error) {
console.error('AsyncStorage error: ' + error.message);
}
}
This will pause the debugger when ever control comes to this block of code.
Step 2:
Press Cmd+D on ios emulator and Cmd+M on Android simulator.
If you are having real device, shake the device to open dev menu, if you don't want to shake device follow this blog
Step 3:
Select Enable Remote JS Debugging, this will open Chrome
Step 4:
Select Developer Tools.
Step 5:
Your debugger is paused in Sources tab wherever you have written debugger within your code . Go to console and type any parameters you want to debug (that are present in the code block) like:
To move to next debugger point again move to Sources -> click on Resume script execution button (Right corner blue button)
Place the debugger, wherever you wanna pause the script.
Enjoy debugging!!
There is also a very good debuger name Reactotron.
https://github.com/infinitered/reactotron
You don't have to be in debug mode to see some data value and there is a lot of option.
go have a look that is really usefull. ;)
I'm a .NET developer but I like JAVA so in my free time I play around with that. I don't normally use Eclipse but I installed the ADT eclipse plugin and Andriod SDK and I started learning and I made a new project with a TableLayout and it kinda looks good, and it runs ok on the emulator.
However... there a few things that drive me absolutely catatonic and perhaps I am doing something wrong so please help me out.
Firstly, if I change the main.xml file in whatever way, even by adding what is supposedly a correct parameter, it will start freaking out and will generate an error that just says "error" without specifying what that is, it will then generate a main.out.xml and then report an error that the main.out.xml is empty. It later won't let me delete that and will start generating a main.out.out.xml and so forth, even after I correct that original xml that caused the error.
The only way to get things going is to delete the bin folder, restart Eclipse, delete all the out xml files and then sometimes it will run the application or some other times it will start generating those 'out' files again and the loop goes on.
That way it takes hours to run a simple app even one without errors that used to run before.
Surely that was NOT how they intended it to work, is it??
Also.. there is no "Rebuild" button that will flush all files out automatically, or is it hidden somewhere? I am tired of manually deleting those automatically generated files and the build folder and all those out.xml files.
Also, while I'm at it, I also want to point out that the designer view sometimes disappears and there is nothing on earth that will bring it back, the only way is to create a new project and copy the main.xml to it and then it shows up again. Another bug?
I have the latest eclipse version:
Version: Indigo Service Release 2
Build id: 20120216-1857
If you have any clues how to get this to work, I will appreciate it!
Many thanks in advance
When you click the Run button with an XML file selected, Eclipse is running an XSL Transformation on that XML and producing the .out.xml file as the result. This is a feature of the Eclipse Web Tools feature, which you'll have if you installed the Eclipse for Java EE Developers package (it may be included in other packages, too).
As others have said above in the comments, to run your Android app, select the Project, right-click, and choose Run As > Android App. Once you've done that once, it will create a Launch Configuration that you can launch from the Run or Debug toolbar buttons (pressing the small down-arrow on the Run or Debug buttons brings up a list of Launch Configurations that you can select from, as well as an option to manage them).
There is a Preference that will make Eclipse always launch the last thing you ran or debugged, instead of trying to be smart about what is currently selected. Open the Preferences and navigate to Run/Debug > Launching; there you'll find the option under Launch Operation at the bottom of the window.