Fields and `to_dict`

I’m currently trying to implement a new Field to abstract the storage of a complex object. The goal is to continue using this object in the python code, and have it stored correctly in Elasticsearch:

class ComplexField(Field):

    def to_dict(self):
        d = super().to_dict()
        return {
            # my representation
        }

    def to_python(self, data):
        return Complex(*data)

class MyDoctype(DocType):
    complex = ComplexField()


complex = Complex()

md = MyDoctype()
md.complex = complex

The problem is that I never see to_dict called when the object is saved, but to_python is called during the initialization.

How can I solve this ?

thank you.

[honzakral]

CustomField added in a5b614d2ab7c6a2fdd49e9d01a0204bd2fd0c565, now only to add documentation…

[honzakral]

Just pushed to master commits f404c8b and 4d2bfd9

I decided to go with the name (de)serialize for the methods, there is an example in the tests for a custom field (https://github.com/elastic/elasticsearch-dsl-py/blob/master/test_elasticsearch_dsl/test_document.py#L42-L59) showing how it would work. I still intend to create a CustomField helper to make it easier (avoid having the user reimplement the to_dict method).

I am not 100% sure on the naming, but the functionality seems to work just fine. I would be happy for any feedback.

Thanks