How to prevent a role from creating a file at the File Library root?

[nicksergeant]

Potential bug?

We have a number of clients in our Directus instance and each one has their own file library folder directly under the root file library folder. We want to prevent them from uploading files into the actual file library root since they will not be able to view anything outside of their folder.

The file permission we are trying to use is:

    {
      action: 'create',
      validation: {
        folder: {
          _nnull: true,
        },
      },
    },

[hanneskuettner]

The problem here is that the folder field is not transmitted on item creation and is therefore undefined and not null.
I opened a separate issue #22278 that aims to deal with the problem of detecting unsubmitted fields.

For your situation a valid workaround seems to be to set the field preset to

{
    "folder": null
}

and then use the _nnull filter.

[nicksergeant]

@hanneskuettner awesome! Thanks so much for the workaround here - that does indeed work 👍.