To assist users with understanding how their dynamic widgets may render on specific devices, the application should provide a device pick list of "well known" devices to render the UI widget inside of.

This library may be of use at speeding up the implementation:
https://pub.dev/packages/device_simulator

Different applications will have different themes for their uses. While it's nice that this application can render themes when they're JSON encoded, it'd be even nicer if themes could be saved and loaded so that the widget renders using the selecting theme. This way developers can set a base theme for any / all dynamic widgets they create.

The README is pretty bland and needs to be updated with a better description of the application.

Chrome on Mac OS Big Sur Macbook Air M1

To reproduce -

1. Click from the left panel - Scaffold, container or any widget and hit "Apply"
2. Click on Add Child
3. Pick any child widget and hit Apply
4. Get the error in screen shot

OR

1. Paste the card.json from json_dynamic_widget project in the JSON section. The tree builds correctly
2. Now click on any widget from the tree like Scaffold
3. Click on any other widget
4. Get error in screen shot

Pretty simple. The application works with editing properties, but does not support adding or removing children yet. This is a core feature of the application.