SlugFieldDefinition is a special type of text field provided by the Content Editor module. It creates an editable text field that allows you to adjust the URL of a Content Editor story to a more human-readable form, for example from
The same can be achieved with URI mapping, which is a more generic solution. For more details, see the section A user-friendly path vs full path.
The slug field can only be used in the context of the Content Editor module.
(Excerpted from the Stories app configuration.)
datesAndUrl: ... properties: ... jcrName: $type: slugField label: URL slug placeholder: Add URL slug...
Since the field extends
TextFieldDefinition, you can use the text field properties to configure the field.