JSON Serialisation of Portable Classes

Feature Requests
#1

Could we have a method (to_json, perhaps?) to serialise instances of Portable Classes for use in http endpoints?

#2

The Portable Classes machinery does a lot more than JSON serialisation. A __serialize__ method can return Media, datetime objects, and even other Portable Classes (not to mention the global_data parameter) – and, of course, there’s also a bunch of metadata to instruct the other end on how to reconstruct (which is an internal Anvil protocol subject to change). So, just because a class is portable doesn’t mean there’s a reliable way of turning it to/from JSON!

What semantics would you want from such a system?

#3

Hi Owen - I’m not fully up to speed on the capabilities of Portable Classes although they looked brilliant when I played with them a couple of months ago.

Depending on your answer to Meredydd’s question about semantics, you might find what you need in CleverDict, a package I’ve been working on which is about to release a major update.

It’s already on the install list for Anvil for server-side use. If you’d like a preview, you can install it locally from Test PyPI, or just search the README for ‘json’.

pip install -i https://test.pypi.org/simple/ cleverdict==1.8.0rc5

All the best,
Peter

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#4

OK. This was probably an unreasonable request!

I think I’ll stick to using marshmallow to define serialisation schema. It’s designed to so precisely that job and does it well.

#5

If you are defining a JSON serialisation method, you can choose to use that as your __serialize__ implementation! You could do:

  def __serialize__(self, global_data):
    return self.serialize_to_json()

  def __deserialize__(self, data, global_data):
    return self.deserialize_from_json(data)

or, if your JSON serialization library wants to do all of the object construction:

  @staticmethod
  def __new_deserialized__(data, global_data):
    return json_library.deserialize(type=my_class, json=data)

The Portable Classes system is a superset of JSON serialisation.

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