fix: order in _onChanged of StacSliderState

[p1tt]

Form data in onChanged of the StacSlider is set after running Stac.onCallFromJson. This leads to old data if form data is directly used in the onChanged action of the slider.

Fix is easy and straight forward in:
packages/stac/lib/src/parsers/widgets/stac_slider/stac_slider_parser.dart

Actual code (line 49 to 58):

  void _onChanged(double value) {
    selectedValue = value;
    if (widget.model.onChanged != null) {
      Stac.onCallFromJson(widget.model.onChanged, context);
    }
    if (widget.model.id != null) {
      widget.formScope?.formData[widget.model.id!] = value;
    }
    setState(() {});
  }

To fix the behaviour just reorder the two if's:

  void _onChanged(double value) {
    selectedValue = value;
    if (widget.model.id != null) {
      widget.formScope?.formData[widget.model.id!] = value;
    }
    if (widget.model.onChanged != null) {
      Stac.onCallFromJson(widget.model.onChanged, context);
    }
    setState(() {});
  }

I can make a pull request if you want, but I think the fix is too easy.

[divyanshub024]

Thanks for raising this issue @p1tt. Will check this out and get back to you.