cubicweb #3817571 Add readonly fields [open]

Forms are missing readonly fields, which can be required in some cases.

The way to go would be something like :

  • add a 'disabled' attribute on Input that is added to the generated tag.
  • add a 'readonly' attribute on Field, with the following consequences :
    • process_form_value should always raise a UnmodifiedField (meaning has_been_modified will always be False)
    • 'disabled' should be set on the underlying widget
    • ideally, in the generated form, the field should not appear in _cw_fields and _cw_entity_fields.
  • add the possibility, in uicfg, to ask for an attribute with no update permission to be included as readonly.
done in<not specified>
closed by<not specified>