Since 10.1.0 it is possible to delete files → . The feature works using the delete button on the Files view, however when visiting the file delete form directly on /file/{file}/delete, without a destination parameter in the URL, this happens:
Drupal\Core\Entity\Exception\UndefinedLinkTemplateException: No link template 'canonical' found for the 'file' entity type in Drupal\Core\Entity\EntityBase->toUrl() (line 196 of core/lib/Drupal/Core/Entity/EntityBase.php).
Drupal\Core\Entity\ContentEntityDeleteForm->traitGetCancelUrl() (Line: 87)
Drupal\Core\Entity\ContentEntityDeleteForm->getCancelUrl() (Line: 42)
Drupal\Core\Form\ConfirmFormHelper::buildCancelLink(Object, Object) (Line: 88)
...
The cause of the issue is that ConfirmFormHelper::buildCancelLink() checks for a route-based cancel link if there's no destination, calling ContentEntityDeleteForm->getCancelUrl() .
On a newly installed Drupal 10.1.7 site, where Image module is enabled, create a content type with an image field.
Make sure your account has permission to 'delete own files'.
Add a node and upload an image to the field.
Visit /file/1/delete
Possibly, adding a canonical link template to file entity. This was proposed previously → , but at the time the decision was not to add it.
Active
10.1 ✨
I believe it is intentionally that file entities don't have canonical route.
As @berdir mentioned in comment https://www.drupal.org/project/drupal/issues/2345761#comment-13180034 →
files will IMHO remain second-class citizens and we will not introduce an actual canonical route in core, and we decided against having one that points to the physical file.
I'm tagging for sub-system maintainer review to get second eyes.