onStyleLoadedCallback not called on iOS

[woelmer]

Flutter (Channel stable, v1.17.5, on Mac OS X 10.15.5 19F101, locale en-US)
On Master branch of plugin.

The onStyleLoadedCallback is not called in the example app. Notice if you go to 'Place Symbol' and click on add (asset image) or add (network image) it does not work. That is because these images are setup in the onStyleLoadedCallback which is not called on iOS. This works fine on Android.

[TimothySealy]

Hi @woelmer,

I'm trying to reproduce this error but everything seems to work on my device. If I click on add(asset image) or add(network image) the symbols are shown with a mapbox icon or placholder image respectively. Looking at the code the onStyleLoadedCallback should be trigger:
https://github.com/tobrun/flutter-mapbox-gl/blob/4ce26231f3250b598060063d1b8b65950694754e/ios/Classes/MapboxMapController.swift#L525-L527

Can you verify that the onStyleLoadedCallback is not triggered by adding a breakpoint of print statement in this method:
https://github.com/tobrun/flutter-mapbox-gl/blob/4ce26231f3250b598060063d1b8b65950694754e/example/lib/place_symbol.dart#L48-L51

[lj64]

I experienced the same issue just yesterday in my project on ios.

onStyleLoadedCallback fired on first entry into the page containing map.
When I closed it and opened again, it did not fire, even though map tiles were displayed.

On Android everything was fine.

[TimothySealy]

Just tested it a couple of times and it seems that the onStyleLoadedCallback is not always fired. On my device in most cases the style is loaded properly but some times it is not and then the icon images are not loaded. Will have to look deeper into this issue.

[woelmer]

@TimothySealy The new recommendation is to add symbols in the onStyleLoadedCallback which is why I noticed it in my own project. I thought I would try out the example and noticed the same thing. I had breakpoints there that were not getting hit. I did have it successfully call the callback once if I recall, so I guess it is intermittent like you noticed.

[philiplindberg]

Seeing the exact same thing as @woelmer - tapping on add (asset image) or add (network image) in the example app does nothing on ios because onStyleLoadedCallback is never called.

The only time I can get onStyleLoadedCallback to be called on ios is after reinstalling the app. When the map is generated for the very first time, onStyleLoadedCallback does get called on both ios and android, but every time after that, onStyleLoadedCallback is only called on android.

[m0nac0]

@woelmer @philiplindberg If you previously added your annotations before onStyleLoadedCallback was fired and that worked for you, you can continue to do this as a workaround. The new documentation wasn't added because we changed any behavior. Adding annotations in onStyleLoadedCallback was always recommended (just less visibly).

[AAverin]

I can confirm the issue. Have not been testing on iOS for some time, so not sure when it started happening exactly.
I have updated to 0.8.0 release and also upgraded Flutter to latest available.
Android seems to work fine, on iOS onStyleLoaded is not invoked when map shows.
If I manually (via setState) change map style, callback is invoked, but I do get a crash almost instantly after that. Not sure it's related.

[edufpin]

Happening with me too, my workaround is check OS and if iOS do it manually after onMapCreated.

[AAverin]

Issue is still present on latest master, after the supposed fix was merged. @andrea689 Was the issue fixed in your tests?

[AAverin]

Ok, this was an issue on my side, didn't update properly. Seems to be more stable now, I'll keep testing

[AAverin]

This is still completely unstable for me.
Sometimes callback is called, but most of the times it isn't

[AAverin]

@tobrun We should reopen it. Style callback is not invoked, but looks like it's not in Flutter, it's not properly called from the native part.
I would assume that this should be long fixed in iOS Mapbox, so we should update to the latest and overall somehow keep dependencies up to date for this project.
#413

[AAverin]

This callback in controller.dart never gets invoked for me

 MapboxGlPlatform.getInstance(_id).onMapStyleLoadedPlatform.add((_) {
      if (onStyleLoadedCallback != null) {
        onStyleLoadedCallback();
      }
    });

[AAverin]

Debugging in Xcode, this line is being correctly called

channel.invokeMethod("map#onStyleLoaded", arguments: nil)

But when debugging in flutter, this invocation somehow doesn't come to MethodChannelMapboxGl._handleMethodCall. All other methods, like onMapIdle, are correctly invoked.

Could it be related somehow to await _channel.invokeMethod('map#waitForMap'); call?

[AAverin]

I have found what's going on.

If I modify method_channel_mapbox_gl.dart like this:

 @override
  Future<void> initPlatform(int id) async {
    assert(id != null);
    _channel = MethodChannel('plugins.flutter.io/mapbox_maps_$id');
    _channel.setMethodCallHandler((MethodCall call) async {
       print("${call.method} invoked before map was ready");
    });
    await _channel.invokeMethod('map#waitForMap');
    _channel.setMethodCallHandler(_handleMethodCall);
  }

onStyleLoaded callback on iOS will be invoked before map was ready.

@tobrun @m0nac0 Could you please help us out with this critical issue on iOS? I am not sure how to properly modify iOS MapBox code to run properly.

[AAverin]

@andrea689 web support refactoring might have been the cause of this issue, this PR #223

[AAverin]

@tobrun @m0nac0 this issue is a critical blocker for my project and I can't release until it is resolved.
Can I help you more in any way pushing this forward? I have already found the cause of the problem and would need some guidance from iOS to make a more robust native MapBox implementation.

[andrea689]

Hi @AAverin can you share a minimun app example with this problem? I have a production app and no have problems. If you want, try my app: https://apps.apple.com/it/app/3bee-i-tuoi-alveari/id1533079866

[AAverin]

@andrea689 Looks like it's not as straightforward as I thought. I had this bug all the time during development, but release build looks to be working fine at the moment. I will try to compare and provide more details, but overall it seems that it is possible that onStyleLoaded will be invoked before waitForMap have finished. Even if it only happens on dev builds, I think it needs some kind of fix.

[andrea689]

@AAverin with #418 I fixed this. If onStyleLoadedCallback is called before the controller.isCompleted (waitForMap), I wait for controller future and after call onStyleLoadedCallback

https://github.com/tobrun/flutter-mapbox-gl/blob/7861b62ee1d396439d44ebb1f84563244aa6bf82/lib/src/mapbox_map.dart#L217-L243

[AAverin]

@andrea689 I will take a look again, but now I am using latest master and I am pretty sure I still had issue on dev builds

[gabeschine]

I also experience this. It seems racy: sometimes it is called, most times it is not. It is easy enough to reproduce by using "hot restart" in flutter.

[keehoo]

Still an issue in 0.10.0 ;(

[manhlhvm]

Still an issue in 0.10.0 ;(

me too :(

[AAverin]

So far for me the issue only seems to reproduce on debug builds. Release builds seem to be fine, at least no users have complained yet.

[keehoo]

So far for me the issue only seems to reproduce on debug builds. Release builds seem to be fine, at least no users have complained yet.

@AAverin I was able to reproduce this on both release & debug (iOS)... I'm also not sure whether I saw this happening on Android, will check more and get back here if find anything.

[AAverin]

Debugging this issue, it seemed as native methods inside Mapbox SDK were not called.
Because flutter-mapbox uses some old versions of Mapbox SDK I have created #413

[jgrandchavin]

I have exactly the same problem on iOS, still any solution found ?

[Sar777]

any news?

[pdcolandrea]

still an issue on 0.12.0, only happening on ios I believe

[AAverin]

I can also confirm this happening in production builds on real devices.
OnStyleLoaded callback is completely inconsistent on iOS

[AAverin]

Some debugging results.
map#onStyleLoaded gets called before map#waitForMap, which means that _handleMethodCall in dart is not yet attached correctly and onStyleLoaded invocation will not reach dart codebase.
This results in the bug we have here.

[AAverin]

Opened a PR with a fix

[samderlust]

I still have this issue with Mapbox 0.14.0?

[AAverin]

@samderlust In that case we would need your help debugging the issue.
Last fixes for for onStyleLoaded callback reliability were applied in this PR: #808
If you can reliably reproduce the problem can you try debugging your app to see what is the cause exactly?

[samderlust]

@AAverin thanks, it fixed with mater branch

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.