RiveStateMachineException after migrate from 0.13.20 to 0.14.0-dev.6

[phuc-tranh-otsv]

RiveStateMachineException after migrate from 0.13.20 to 0.14.0-dev.6

When I change from 0.13.20 to 0.14.0-dev.6 & run my app, I got the error: RiveStateMachineException with message "Default state machine not found."

When use rive version 0.13.20, all the rive file still display correctly.

[phuc-tranh-otsv]

Stacktrace:
[ERROR:flutter/runtime/dart_vm_initializer.cc(40)] Unhandled Exception: RiveStateMachineException: Default state machine not found.
[ ] E/flutter (30025): #0 RiveWidgetController._createStateMachine (package:rive/src/painters/widget_controller.dart:73:7)
[ ] E/flutter (30025): #1 new RiveWidgetController (package:rive/src/painters/widget_controller.dart:33:20)

[phuc-tranh-otsv]

Code:

`late rive.File? file;
late rive.RiveWidgetController? controller;
bool isInitialized = false;

@OverRide
void initState() {
super.initState();
initRive();
}

Future initRive() async {
file =
(await rive.File.asset(widget.image, riveFactory: rive.Factory.rive))!;
controller = rive.RiveWidgetController(
file!,
);
setState(() => isInitialized = true);
}

SizedBox(
width: 200,
height: 200,
child: isInitialized && controller != null
? rive.RiveWidget(
controller: controller!,
)
: const CircularProgressIndicator(),
),
`

[phuc-tranh-otsv]

After recheck, I think root cause is missing stateMachineSelector when create RiveWidgetController.
If I use stateMachineSelector is StateMachineDefault, system throw RiveStateMachineException.
But, when set stateMachineSelector system display correct animation.

[phuc-tranh-otsv]

Can you explain how to work without StateMachineDefault in rive version ^0.14.0-dev.x?

[phuc-tranh-otsv]

@HayesGordon Can you explain how to work without StateMachineDefault(old riv file) in rive version ^0.14.0-dev.x?

Because, version 0.13.0 I set list stateMachine is empty and it work. But with new version it not work for me.

Thank you so much!

[HayesGordon]

There is probably no state machine on the artboard you're trying to play. In the editor you can create a blank state machine and just transition into the animation you want to play.

But we've also updated our underlying code to now automatically create a state machine for you at runtime if there is nothing in the .riv file and you're using the defaults. If you update to the latest version this issue should be resolved.

We recommend always using a state machine to play a graphic (even if it's just a simple animation).

Or if you want to play an animation instead of a state machine, you can look at this: https://github.com/rive-app/rive-flutter/blob/master/example/lib/examples/animation_painter.dart

Closing this, as this is now expected behaviour.

[phuc-tranh-otsv]

@HayesGordon Thank you for your comment. I will try to play an animation instead of a state machine by SingleAnimationPainter.

[phuc-tranh-otsv]

Hi @HayesGordon ,
I try to play an animation instead of a state machine by SingleAnimationPainter. But, I don't remember the value of 'animationName' when create SingleAnimationPainter('???').
How to get the animation name from .riv file?
Thank you so much.

[phuc-tranh-otsv]

Hi @HayesGordon,
I try to get artboard, animations & stateMachines by old version 0.13.20 but all value is empty & null.
How to version 0.14.0-dev.x can work with artboard, animations & stateMachines = null or empty?
Thank you so much.

[jamesncl]

Hi @HayesGordon, I try to get artboard, animations & stateMachines by old version 0.13.20 but all value is empty & null. How to version 0.14.0-dev.x can work with artboard, animations & stateMachines = null or empty? Thank you so much.

I had the same issue when upgrading to 0.14 - I have some old Rive animations I made years ago with single timeline animations, no state machines. In previous versions I could just use the RiveAnimation.asset("path/to/asset") widget, and it would start the animation without needing to specify any arguments.

Luckily I had exported them from the rive.app editor as .rev files for backup, so I was able to import them back into the editor and check what my animations were called. They were all called 'Animation 1', which I guess was the default name. So, if you no longer have access to your original editor files, you might want to try 'Animation 1' as the animation name, it might work. Alternatively you might be able to query your compiled .riv file at runtime using a RiveWidgetController and calling something like controller.artboard.animationAt(0).name and print it to console?

Maybe there is an easier way to do this, I haven't had time to explore the new 0.14 API yet. It would be nice if there was an equivalent convenience widget to replace the old RiveAnimation.asset("path/to/asset") for single animations for others who are upgrading to 0.14, or be able to do something like SingleAnimationPainter.defaultAnimation()

[HayesGordon]

You can use a painter created just for playing animations, see this example: https://github.com/rive-app/rive-flutter/blob/master/example/lib/examples/animation_painter.dart

But what you're suggesting about a RiveAnimation widget to bridge the old behaviour is a good idea, and we can look into adding it to help migration.