Components (widgets) in server modules

Anvil Q&A
1

Can widgets / components be created in server modules, like in

@anvil.server.callable
def createLink():
  l = Link(text="Some link")
  return l

I can see anvil.Component(), but don’t know what it is :blush:

I’m creating a dynamic menu from records in db and would like to create everything on the server and then pass an array of links.

Furthermore, can a reference to a function be passed to a server? I get a serialization error when I call a server function defined as:

@anvil.server.callable
def createLink(eventHandlerFunction):
  l = Link(text="Some link")
  l.set_event_handler("click", eventHandlerFunction)
  return l

Maybe I just want too much :sunglasses:

2

Don’t think so. No - see second part about RPC.

I would return the data for the links from the server and then create the links themselves on the form. Think that broadly achieves the same result?

Steps would be roughly :

  • call a server function from your form to create a list of link urls (and text)
  • dynamically create a link from the returned data in the form
  • add the link to your menu placeholder.
  • iterate over the returned data until all links have been created

Something like that.

No, server comms is over RPC and the manual says :

Arguments and return values to RPC calls can be strings, numbers, dicts, lists, datetime.date/datetime, and None, and may not be circular.

Full details here : Anvil | Reference

1 Like
3

Many thanks for explanation and a link to documentation. I’ll do it as you suggested.

4

I have made a habit of just doing everything between the server and a Form as a JSON object. It keeps things simple and is pretty flexible.

5

What about pickle? According to this article pickle is more “native” to Python. I’m relatively fresh in Python, coming from the world of c#, java, js, etc. …

6

Pickle handles almost anything. I have used it to save somewhat complicated objects.

The downside: it is not necessarily portable from one OS / machine / processor to the next, so think of it as a way to store but not transport data.

1 Like
7

… besides, with pickle I get “NotImplementedError: pickle is not yet implemented in Skulpt” …