What's the best way to compare periods? about fhir.resources HOT 5 CLOSED

For anyone that finds this thread because they want to know how to add a root validator to a pydantic model without touching the model itself, there's one critical thing that was missing from @nazrulworld's example above. The validator function must return the values. Here's approximately what I'm doing in my validator:

from typing import Dict

from fhir.resources.DSTU2.period import Period

from .parse_helpers import parse_end_time, parse_start_time


def normalize_period_dates(cls, values: Dict):
    if not values:
        return values
    raw_start = values.get("start")
    raw_end = values.get("end")
    if raw_start:
        values["start"] = parse_start_time(raw_start)
    if raw_end:
        values["end"] = parse_end_time(raw_end)
    return values


class Shims:
    _done = None

    @classmethod
    def setup_shims(cls):
        if Shims._done:
            return
        # Add all root validators here
        Period.add_root_validator(normalize_period_dates, pre=True)

        Shims._done = True


Shims.setup_shims()

from fhir.resources.

@mmabey first of all thank you much for your help to improve the strength of this package.

However, I can explain about Date, dateTime of FHIR.

1. as we know about flexibility of FHIR date format (some of incompatible with python date, datetime), to keep that in mind, fhirtypes.Date and DateTime returns string value if parts of date provided, for example only year and/or month. [we don't want loose original information in general], even DateTime type may return Date object if only year-month-day is provided.

What about business requirements like yours?

This library uses pydantic's validator strength to allow custom root validator for each model. I cannot make full documentation yet. But here example code

from fhir.resources.period import Period

def my_pre_period_validator(cls, values):
    """ """
    raw_start = values["start"]
    raw_end = values["end"]
    # do check raw values, if need add missing part of
    # date. even possible to make date object
    values["start"] = raw_start # modified
    values["end"] = raw_end # modified

Period.add_root_validator(my_pre_period_validator, pre=True)

this function should be called my_pre_period_validator before constructing Period object, here you will have access to raw value.

from fhir.resources.

This is a very interesting feature of pydantic, thanks for sharing!

If I'm understanding your example correctly, the modified Period class would only be accessible to code that imported Period from the Python file where this modification takes place, for example (assuming your example is stored in my_fhir_shim.py):

from my_fhir_shim import Period

Is this ☝️ correct? If so, I'm not sure it helps me. For all of the FHIR objects I construct, I don't know beforehand what resource type I'm creating, so I'm making heavy use of the FHIRElementFactory/construct_fhir_element feature of this library.

In any case, I'm not creating Period objects directly, they're all being created as a sub-element (sometimes a sub-sub-sub-element) of something else. For example, a Claim resource has an Identifier which contains a Period. I'll make some local tests to see if it's possible to use a root validator, but if it isn't possible, do you have any other suggestions?

from fhir.resources.

I think you are almost got it, I am trying to minimize some misunderstanding. I am taking your example, the file name is my_fhir_shim .py.

1. once this my_fhir_shim module is imported anywhere at runtime, for example in your package root __init__.py import my_fhir_shim That's all!
2. you don't need to from my_fhir_shim import Period and should not worry about whether you are constructing Period manually or automatically by pedantic. All should work as expected, your function will be called before period instance creation is done.
3. import Period from the standard place if you are constructing manually.
4. Keep in mind this should bePeriod.add_root_validator(my_pre_period_validator, pre=True) in one place across your project per function, which means the same function should not add multiple time.

from fhir.resources.

That makes so much more sense. Thank you for clarifying! It looks like it will be a while before I'm able to make another attempt at using a root validator in my project. I'll reopen if I'm unable to figure it out. Thanks again!

from fhir.resources.