Server-side methods

Sometimes you might want to define a method on the client but have it run on the server. You can do this with the @anvil.server.server_method decorator.

For example, the following code defines a Person class that has a method to check whether or not the person is in a Data Table. When that method is called, the Portable Class is sent to the server and the server method is called there.

import anvil.server

@anvil.server.portable_class
class Person():
    
    def __init__(self, first_name, last_name):
        self.first_name = first_name
        self.last_name = last_name
    
    @anvil.server.server_method
    def is_in_database(self):
      return bool(app_tables.people.get(first_name=self.first_name, last_name=self.last_name))
      

Using @anvil.server.server_method is the equivalent of defining the method on the server and using anvil.server.call on the client:

def is_in_database(self):
  return anvil.server.call('check_database', self.first_name, self.last_name)

@anvil.server.callable
def check_database(first_name, last_name):
  return bool(app_tables.people.get(first_name=self.first_name, last_name=self.last_name))

Using server methods securely

You can only call a server method on an instance of your Portable Class, but the contents of your class are generally untrusted just like the arguments to an anvil.server.call() call. You should only rely on trusted information, for example, code from the server or Capabilities.

Do you still have questions?

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