I would like to be able to display a message in the case all the fields of a given set are empty.

A possible spec would be :

<sib-display
  data-src="https://ilikeit.here/"
  fields="address(number, street, zipcode, city)"
  empty-address="no-address"
  empty-address-value="edit-group"
></sib-display>

<sib-widget>
  <template>
    <p>No address yet. Please provide one <sib-link next="${value}">here</sib-link></p>
  </template>
</sib-widget>