[16.0][IMP] extendable_fastapi: Add generics schemas

[lmignon]

Add base schemas to be used to define pagination and paginated results when defining a search router.

[lmignon]

@sbidoul @sebastienbeau @qgroulard I'm not sure it's the right place to define these base schemas. Even if they are mainly used with fastapi, we also use the StrictExtendableBaseModel when we define models to be stored into a search engine. This leads to a useless dependency on fastapi. Do we've to create a specific addon for the StrictExtendableBaseModel? I could also move it to the extendable_fastapi python lib.

[sbidoul]

I could also move it to the extendable_fastapi python lib.

But this PR is for extendable_fastapi ?

Question: why would one want to extend PagedCollection or Paging? Or is this necessary for compatibility when T is extendable?

[lmignon]

Yes, at least for PagedCollection, it's necessary for compatibility when T is extendable.

Regarding StrictExtendableBaseModel, it's not defined at the right place or we should not use-it when defining schemas for the search engine index.

[sbidoul]

Ah, yes I see. So you mean defining StrictExtendableBaseModel in extendable_pydantic, right?

[lmignon]

yes

[sbidoul]

Ok, makes sense to me. Let's do that.

[sbidoul]

Probably too late but... is count a better field name than total?

[lmignon]

IMO, It's not too late. What do you propose? count ?

[sbidoul]

Yes count, but it's not very important.

[lmignon]

Wording is important. I find a way to ensure the consistency with the same version of the model defined in the fastapi odoo addon but not supporting extendable items. The idea is to deprecated the use of the totalfield but keeping the compatibility on both side: json and python

import json
from typing import Annotated
from pydantic import BaseModel, computed_field, Field, AliasChoices


class Paginated(BaseModel):
    count: Annotated[
        int,
        Field(
            ...,
            desciption="Count of items into the system.\n Replaces the total field which is deprecated",
            validation_alias=AliasChoices("count", "total"),
        ),
    ]

    @computed_field()
    @property
    def total(self) -> int:
        return self.count

    @total.setter
    def total(self, value: int):
        self.count = value


p = Paginated(count=10)
print(p.model_dump_json())
>> {"count":10,"total":10}

p = Paginated(total=20)
print(p.model_dump_json())
>> {"count":20,"total":20}

p.total = 30
print(p.model_dump_json())
>> {"count":30,"total":30}

print(json.dumps(p.model_json_schema(), indent=2))
>> {
  "properties": {
    "count": {
      "desciption": "Count of items into the system.\n Replaces the total field which is deprecated",
      "title": "Count",
      "type": "integer"
    }
  },
  "required": [
    "count"
  ],
  "title": "Paginated",
  "type": "object"
}

[lmignon]

I've modified fastapi to ensure consistency between the two declarations in this template

[lmignon]

@qgroulard @AnizR What do you think about this PR?

[AnizR]

Great!

[qgroulard]

Looks good.

[sebastienbeau]

LTGM, tested

[sebastienbeau]

/ocabot merge minor

[OCA-git-bot]

On my way to merge this fine PR!
Prepared branch 16.0-ocabot-merge-pr-380-by-sebastienbeau-bump-minor, awaiting test results.

[OCA-git-bot]

Congratulations, your PR was merged at e9b65cf. Thanks a lot for contributing to OCA. ❤️