Flexible form builder

[thibaudcolas]

Revamp of Wagtail’s form builder, to create more advanced forms with StreamField foundations.

Intended outcome

More flexibility by using a StreamField-based form builder, with support for multi-step forms, and more common customizations. Such as:

• More advanced built-in field types
• Straightforward support for custom field types with their own configuration options
• More configuration options available out of the box (min/max length, custom error messages, autocomplete attribute, etc)

This may be delivered in the form of a new "contrib" app, a replacement of the existing forms contrib app, or a standalone package.

More information

• New StreamField-based form builder
• wagtail-flexible-forms
• wagtail-model-forms

[thibaudcolas]

Tagging this needs contributions as I think clearer use cases for the new StreamField-based form builder would really help push this. I have made a long list of possible requirements in our separate discussions thread, be great to hear which ones people think are most useful, and anything that might be missing.