Running example code results in network error at RN fetch()

[aschrijver]

First of all: Thanks for this project!

I am checking out the /example code and when running as described in the README and without modifications I get following error:

TypeError: Network request failed
    at XMLHttpRequest.xhr.onerror (fetch.js:441)
    at XMLHttpRequest.dispatchEvent (event-target.js:172)
    at XMLHttpRequest.setReadyState (XMLHttpRequest.js:546)
    at XMLHttpRequest.__didCompleteResponse (XMLHttpRequest.js:381)
    at XMLHttpRequest.js:485
    at RCTDeviceEventEmitter.emit (EventEmitter.js:181)
    at MessageQueue.__callFunction (MessageQueue.js:260)
    at MessageQueue.js:101
    at MessageQueue.__guard (MessageQueue.js:228)
    at MessageQueue.callFunctionReturnFlushedQueue (MessageQueue.js:100)

I will look into this further, but maybe there is something obvious I am overlooking..

(Versions: yarn 0.24.6, npm 4.2.0, ubuntu 16.04, (local) node: 7.10.1)

PS I will try again with downgraded node on ubuntu system

[aschrijver]

Downgrading first to 7.1.0, then to 6.9.1 did not solve the issue

[staltz]

Can you try making a release build? (would rule out the case where JS is running on your computer. it would run in the phone)

[staltz]

Oh, and are you running it in an emulator or device? (If device:) Is it 64bit or 32bit (e.g. which arm is it?)

[aschrijver]

I am running in the emulator with a Nexus_5X_API_26_x86(AVD) - 8.0.0

The release build has the same issue I think, but suppresses the error, so nothing happens when clicking link. (have also tried Nexus_4_API_23(AVD) - 6.0 with same result)

But I still have one adb error I can't get rid of (don't know if related to the problem, strange error as I only have one emulator up):

:app:installRelease
Installing APK 'app-release.apk' on 'Nexus_5X_API_26_x86(AVD) - 8.0.0' for app:release
Installed on 1 device.

BUILD SUCCESSFUL

Total time: 11.144 secs
Running adb -s emulator-5554 reverse tcp:8081 tcp:8081
adb server is out of date.  killing...
* daemon started successfully *
error: more than one device/emulator
Could not run adb reverse: Command failed: adb -s emulator-5554 reverse tcp:8081 tcp:8081
Starting the app on emulator-5554 (adb -s emulator-5554 shell am start -n com.example/com.example.MainActivity)...
Starting: Intent { cmp=com.example/.MainActivity }

[staltz]

If you have a device, experiment with that. With emulators, I've had issues in the past when it comes to networking.

[aschrijver]

Yes thx, I was about to do that, but just tested with node-on-android on an arm64 emulator. That works, but it has a bit different install process. Will now try real device. Just checking what proc it has (otherwise I need to boot an old phone).

Update: My own phone is 64-bit Samsung A3 (https://en.wikipedia.org/wiki/Samsung_Galaxy_A3_(2015)). Going to look into the drawers for an old phone :)

[aschrijver]

I just tried a real Samsung S3 Mini, but unfortunately it has the same release build issues as occurred with the emulator.

[aschrijver]

I though this may be the cause: react/react-native#15100 (comment)

So I downgraded to 0.45.1 but unfortunately with the same result. Afterwards for good measure I also tested with a Nexus_5X_API_24(AVD) - 7.0 without success.

Probably the node app is not responding. I cannot load the URL from a webview on the device as well.

[aschrijver]

FYI:

I've tried many different ways to get NodeJS running on Android and spent yesterday all-day compiling without success.
I am investigating some viable-seeming approaches to use NodeJS in an android project. I have documented my findings on stackoverflow - Viable options to running NodeJS on Android (Aug 2017). You are mentioned there as well.

[aschrijver]

Hi @staltz

I got it working by refactoring to J2V8:

Steps:

• clone J2V8
• python build.py --interfactive (using the not-yet-merged build improvement PR)
• import j2v8-release.aar in react-native-node (8.7 MB, Node 7.9.0 for me, soon 8.1.2)
• in react-native-node compile project(':j2v8-release')
• node application is at android/app/src/main/assets (will refactor this to be ./Background)
• remove any non-standard RN stuff from the gradle projects

Then RNNodeService.java like this:

• https://gist.github.com/aschrijver/382f04c578717db4d30b3b2289de3252

(PS You don't need a V8Thread. A normal one will do)

For some reason I had to redefine RNNodeModule.start to have no parameters when called with no parameters from RN, otherwise I ended up with error NativeArgumentsParseException got 0 arguments expected 1. Will look into this later.

I now know much more on J2V8 now (see Viable options to running NodeJS on Android (Aug 2017)) and am convinced that both react-native-node and node-on-android would benefit by using this as a basis to build on further. It would not add any overhead in the way the project is working now, and gives some powerful options in e.g. communicating between RN and Node.

I will keep you posted on more findings.

[aschrijver]

One thing not working well yet in above setup is starting and stopping the Service in the case where the Node app is long-running express webserver (haven't tested with original react-native-node, may be an issue as well). This leads to crashes in the app.

Update I am going to refactor to a bound foreground sticky Service (running always independent of app), with NodeJS on its own thread.

[erikdung]

Any progress here?