Firebase Security Rules - Access a document field

Question

I am trying to check based on a document field, I am trying this:

match /usuarios/{user}/{documents=**} {
    allow read, write: if user.data.uid.matches(request.auth.uid)
}

I am getting this error

Invalid type. There is no type for variable 'user' that satisfies all clauses.

Answer 1

You can access your document data using resource:

match /usuarios/{user}/{documents=**} {
  allow read, write: if resource.data.uid.matches(request.auth.uid)
}