Login methods to accept 'view' objects on the 'users' table

Feature Requests
#1

Hello Friends:

This feature request was inspired by this Q&A post.

The request is to enhance the various login methods (e.g., anvil.users.login_with_form()) to accept views on the users DataTable.

This allows applications sharing a users table to select subsets of it rows (a view) that’s suitable for that application, and present only that subset to the login method.

For example, Application-A may only want users with role employee to be able to log in; while Application-B may allow users with role employee or customer to login in. Currently, logic for this must be implemented post login, where a developer must do something like this:

user_row = anvil.users.login_with_form() # User logs in.
if user_row: # Post login.
    if user_row['role'] == 'employee':
       pass   # Allow or Reject.
    elif user_row['role'] == 'customer':
       pass   # Reject or Allow.

If, instead, something like the following were possible, security would be enhanced because it permits the decision to occur pre-login:

1. role = 'customer' # or 'employee' (or whatever the qualifiers).
2. users_view =  app_tables.users.client_readable(role=role)
3. user_row = anvil.users.login_with_form(users_view=users_view)
4.

Here, users not meeting the view qualifier(s) (dimensions) will be unable to log in since they are filtered-out of the view. This happens pre-login (no if/elif conditionals needed). And, if login is permitted, more is already known about the user by code-line 4.

Security is enhanced because the allow/reject decision occurs pre-login; and because less critical code (and possibly accompanying bugs) is necessary; and because you’re confident that the only users accessing an application are the ones you want.

Thank you.

Using a subset of a users table in a second App
#2

It won’t offer any real security since any user dedicated enough can just replace the line

user_row = anvil.users.login_with_form(users_view=users_view)

with

user_row = anvil.users.login_with_form()

But yes, it will make your code simpler.

#3

Yes a subset of users can, just like a subset of human can pick house locks.

As well, simpler and smaller code footprint increases the probability of safer code across the skillset spectrum, writ large.

2 Likes
#4

Yes. If this was being done for security purposes, then this would need to be a server-side setting.

2 Likes
#5

Yes, and in that case it could be a backend ability to add an existing users table to Application-B, while at the same time (still on the backend) optionally specifying qualifiers to obtain a subset (a view in the relational sense) needed for that application.

#6

Maybe the secure version of the feature request is to be able to share views between apps in addition to entire tables? That’d have nothing to do with login per-se, but if you shared a view on another app’s users table and configured the Users service to use it (all in IDE settings), then the standard Users service calls would automatically use it.

2 Likes