Check observer

[pavanpodila]

This will check the builder function and assert if no observables are detected. I ran into this issue a few days back and took quite some time to figure out that there were no observables being tracked inside! I think this is a good sanity check to have.

[codecov]

Codecov Report

Merging #111 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #111      +/-   ##
==========================================
+ Coverage    95.5%   95.51%   +<.01%     
==========================================
  Files          40       40              
  Lines        1445     1448       +3     
==========================================
+ Hits         1380     1383       +3     
  Misses         65       65

Flag	Coverage Δ
#flutter_mobx	100% <100%> (ø)	⬆️
#flutter_mobx_hooks	100% <ø> (ø)	⬆️
#mobx	95.21% <100%> (ø)	⬆️
#mobx_codegen	93.86% <ø> (ø)	⬆️

Impacted Files	Coverage Δ
flutter_mobx/lib/src/observer.dart	100% <100%> (ø)	⬆️
mobx/lib/src/core/reaction.dart	96.77% <100%> (+0.05%)	⬆️

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[kholdunn]

can we make this optional?
In my case, I want the class to be observer all the time.

Thanks in advance

[pavanpodila]

I think a middle ground would be to not throw an AssertionError and instead only print a warning to the console. Can you send a PR, @kholdunn ? If you are not sure, I can help you out.

[kholdunn]

@pavanpodila
thnx for prompt reply!

Observer( builder: (_) => RaisedButton( onPressed: () {}, ), ),

I tried that, it is showing this error

flutter: #377 RenderObjectToWidgetElement.mount package:flutter/…/widgets/binding.dart:904 flutter: #378 RenderObjectToWidgetAdapter.attachToRenderTree.<anonymous closure> package:flutter/…/widgets/binding.dart:850 flutter: #379 BuildOwner.buildScope package:flutter/…/widgets/framework.dart:2253 flutter: #380 RenderObjectToWidgetAdapter.attachToRenderTree package:flutter/…/widgets/binding.dart:849 flutter: #381 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.attachRootWidget package:flutter/…/widgets/binding.dart:736 flutter: #382 runApp package:flutter/…/widgets/binding.dart:780 flutter: #383 main package:blocapp/main.dart:17 flutter: #384 _runMainZoned.<anonymous closure>.<anonymous closure> (dart:ui/hooks.dart:189:25) flutter: #389 _runMainZoned.<anonymous closure> (dart:ui/hooks.dart:180:5) flutter: #390 _startIsolate.<anonymous closure> (dart:isolate/runtime/libisolate_patch.dart:300:19) flutter: #391 _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12) flutter: (elided 6 frames from class _AssertionError and package dart:async) flutter: ════════════════════════════════════════════════════════════════════════════════════════════════════ flutter: Another exception was thrown: A RenderFlex overflowed by 99377 pixels on the bottom.

[pavanpodila]

looks like you have other layout related error here. Also, you don't need an Observer if you are not watching any observable.

[kholdunn]

@pavanpodila That's correct, but in my case, I'm using my own widget class which extends a native widget.
By default, my class is extending the widget and linking its properties to the store.

In the constructor, I'm receiving the properties and overriding them, by that, I might override all default properties, then I won't be able to have an observable.

class FabAtom extends FloatingActionButton {
  final FabProps fabProps;

  final floatingActionPointTheme = StoreSingleton.fabTheme;

  FabAtom({this.fabProps});

  Widget build(BuildContext context) {
    return Observer(
      builder: (_) => FloatingActionButton(
            onPressed: fabProps.onPressed,
            tooltip: fabProps.tooltip,
            foregroundColor: fabProps.foreColor != null
                ? fabProps.foreColor
                : floatingActionPointTheme.foreColor,
            child: fabProps.child,
            backgroundColor: fabProps.backColor != null
                ? fabProps.backColor
                : floatingActionPointTheme.backColor,
            mini: fabProps.mini != null
                ? fabProps.mini
                : floatingActionPointTheme.mini,
            elevation: fabProps.elevation != null
                ? fabProps.elevation
                : floatingActionPointTheme.elevation,
            shape: fabProps.shape != null
                ? fabProps.shape
                : floatingActionPointTheme.shape,
            materialTapTargetSize:
                floatingActionPointTheme.materialTapTargetSize,
            clipBehavior: fabProps.clipBehavior != null
                ? fabProps.clipBehavior
                : floatingActionPointTheme.clipBehavior,
            isExtended: floatingActionPointTheme.isExtended,
          ),
    );
  }
}

[pavanpodila]

@kholdunn Interesting use case. Can you file an issue for this. I'll work on it next week.