server only functions

[amitu]

A function in fastn can be written with $server$: true to declare itself to be a server function:

-- integer foo(x, y):
$server$: true
integer x:
integer y:

.. body omitted ..

When foo is called from server, the body will be executed in line during page generation, but if it is called from client it will become an AJAX call, and will be executed on server and response would be sent.

A bit like this:

[amitu]

Server Functions During SSR and Hydration

It would be not smart to call server function both during page generation on server side during initial page load and again in client side during hydration.

So we should call all server functions on server during SSR, and store the result of each such function, and include in the page itself, so when the function is called during hydration we do not have to make Ajax call.