OptionalcanvasOptionalcreationCallback function to dynamically filter which document types can be created from this reference field based on the current document state.
This allows you to conditionally restrict the types available in the "Create new" dropdown based on other field values in the document.
Important: This only affects document creation, not which existing documents
appear in search results. To filter search results, use the filter option instead.
OptionaldisableWhen true, hides the "Create new" button in the reference input,
preventing users from creating new documents from this field.
For more granular control (e.g., allowing creation of only specific types,
or conditionally hiding the button based on document state), use the
creationTypeFilter option instead.
Optionalsanity
BaseOptionsapplies to all type options.It can be extended by interface declaration merging in plugins to provide generic options to all types and fields.