No way to set FormContext

[stocks29]

The FormContext is explicitly set within FormRenderer without allowing for the component consumer to set/override any values. This makes it very difficult to base on field off of another, such as updating a state/province dropdown to display states once a country has been selected.

The formContext object You can provide a formContext object to the Form, which is passed down to all fields and widgets (including TitleField and DescriptionField). Useful for implementing context aware fields and widgets.

From: https://react-jsonschema-form.readthedocs.io/en/latest/advanced-customization/#the-formcontext-object