User management consists of two aspects: authentication (checking who people are, login) and authorisation (deciding what they can do based on who they are).
Authorisation is quite simple in Anvil: you check the current user and use Python logic to allow or deny them access to data and functionality.
Checking who’s logged in
You can get the current logged-in user with
anvil.users.get_user(). Do this when they are about to do something for which they need to be authorised (e.g. access private data).
anvil.users.get_user() function returns the Data Table row from the Users table for the currently
logged-in user. If no user is logged in, it returns
In this example, we check the user’s email address. If this is an authorised user, we give them access to some secret data (by returning a client-readable view on a data table).
@anvil.server.callable def get_secret_data(): user = anvil.users.get_user() if user['email'] == 'firstname.lastname@example.org': return app_tables.secret_table.client_readable()
You can pass an optional keyword argument
get_user(), which is
True by default.
Setting this to
False will prevent
get_user from returning a User who logged in in a previous session and selected “Remember me”.
anvil.users.get_user() can be used from Server Modules and from client code. To be sure that the results are correct, you should call it from a Server Module.
The user has ultimate control of anything running in their browser, but the server environment is secure.
anvil.users.get_user() accesses the database if a cache miss occurs, so making the call from client code causes a spinner to be displayed.
To suppress the spinner, run it in a
with anvil.server.no_loading_indicator block.
You can easily set up user roles to define groups of users that have certain permissions. Just add a
to your Users table.
Imagine you wanted to designate some users as
admin users. You can put
'admin' in the
role column for
those users, then check the
role column when you’re deciding what access to give them:
@anvil.server.callable def get_secret_data(): user = anvil.users.get_user() if user['role'] == 'admin': return app_tables.secret_table.client_readable()
You can combine user roles with Data Tables views to show only certain records depending on user roles. Just store a ‘role’ column on the table you want to restrict, and store which role can view each row. If it’s multiple roles, use a Simple Object with a list of roles.
@anvil.server.callable def get_secret_data(): user = anvil.users.get_user() return app_tables.my_table.client_readable(role=user['role'])
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