Adding county information to API

[JKSenthil]

County information is retrieved from CSBS (https://www.csbs.org/information-covid-19-coronavirus). Endpoint is /v2/locations?source=csbs. Added unit tests and added documentation in readme for the county addition.

[ExpDev07]

Damn, very well done! However, not sure I agree on the way the service is injected. I believe we'd be better off using a middleware to dynamically retrieve the data-source service.

E.g:

@api.before_request
def datasource():
    """
    Attaches the datasource to the request.
    """
    
    # Retrieve the datasource.
    source = request.args.get('source', type=str, default='jhu')

    # Attach source to request and return it.
    request.source = services.locations.get_datasource(source)
    pass

I am currently writing this right now.

[JKSenthil]

Yeah, having a middleware would definitely be better. Feel free to let me know if you have any questions or other comments!

[ExpDev07]

I started some ground-work here: #115.

[ExpDev07]

Hello, @JKSenthil! It should now be done, if you still want to add your source, a couple of things:

You're only allowed to return instances of Location. You may create a subclass like below (suggested implementation). You can add fields, but not edit nor remove them. If no data is available for it, just pass an empty string or 0:

from . import Location

class CbsLocation(Location):
    """
    A CBS location.
    """

    def __init__(self, id, country, state, county, coordinates, last_updated, confirmed, deaths):
        super().__init__(
            # General info.
            id, 'US', state, coordinates, last_updated,

            # Statistics.
            confirmed=confirmed,
            deaths=deaths,
            recovered=0, # not provided
        )

        # State and county.
        self.county = county
        self.state = state

    def serialize(self):
        """
        Serializes the location into a dict.


        :returns: The serialized location.
        :rtype: dict
        """
        serialized = super().serialize()

        # Update with new fields.
        serialized.update({
            'state'   : self.state,
            'county': self.county,
        })

        # Return the serialized location.
        return serialized

Then simply create your service for retrieving the locations, and register it in data/__init__.py. Your service should return a list of locations, not a dict like in your pull request. Simply just use index as id. Now your work is done. You don't have to do anything in the routes. You'll have fields such as "province" and "state" saying the same, but that's not really a big deal, and will provide compatibility across the data-sources.

I can work on implementing a more universal form for sending query params through to the services so we don't mess up the routes later. I just did it the easy way with country_code, but it should really be moved out of the routes module.

Happy coding! I might write a guide on adding data-sources later, but this ^ is a quick summary of it.

[JKSenthil]

Great, thanks for the details! I'll get to work.

[ExpDev07]

Well done :). I left a comment regarding the Last Update. To not confuse people, we should follow one format, which is UTC ISO (with an added 'Z' at the end for UTC).

[ExpDev07]

Should be parsed as ISO with an added 'Z' at the end. Use import datetime from datetime to achieve this.

[JKSenthil]

fixed!

[JKSenthil]

I have finished up the csbs service and integrated it via the middleware, so everything is working. I think the only "issue" is that is /v2/locations.py, the serialising step passes in a timelines which the csbs doesn't use. For now, I pass in a dummy timelines in serialize(), is that fine?

[ExpDev07]

@JKSenthil

the serialising step passes in a timelines which the csbs doesn't use. For now, I pass in a dummy timelines in serialize(), is that fine?

Yes, that's fine. I'll fix it later. It's really just about checking if the Location is an instanceof TimelinedLocation before we pass in the timelines argument in the routes, I'll sort it, don't worry, for now it's fine.

[ExpDev07]

Looks good!

[ExpDev07]

Hey @all-contributors please add @JKSenthil for code, documentation, and tests.

[allcontributors]

@ExpDev07

I've put up a pull request to add @JKSenthil! 🎉