This page is part of the HotBeverage FHIR Implementation Guide (v1.4.2022: Release) based on FHIR R4. . For a full list of available versions, see the Directory of published versions

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Official URL: http://fhir.org/guides/acme/HotBeverage/ImplementationGuide/fhir.acme.hotbeverage				Version: 1.4.2022
Active as of 2022-04-01				Computable Name: HotBeverage

Scope and Usage

Based on IETF RFC 2324 - Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0) and its update, RFC 7168 - The Hyper Text Coffee Pot Control Protocol for Tea Efflux Appliances (HTCPCP-TEA), this resource allows for the fulfillment of a device request for an artfully brewed caffeinated beverage, but coffee shares this quality with many other varied preparations based on the filtration of plant material. Foremost, among these are the category of brews based on the straining of water through prepared leaves from a tea tree.

Boundaries and Relationships

This resource may relate to NutritionOrder with the variance that the subject may be Patient, Practitioner or, possibly, RelatedPerson if that individual is not responding to conventional awakening therapy.

This also has a need for a sub-class of Device to allow for coffeepot, teapot and, potentially additional classes of espresso machine and cappuccino machine with associated responses.

Background and Context

IETF RFC 2324 and 7168 outline the creation of the HTCPCP which uses a modified header for the BREW/POST and message/[coffee/tea]pot mimetypes.

FHIR uses only the standard http protocols which will limit the ability for appropriate caffeination of Person(s) as needed. As such, it was felt that taking these Pre-FHIR RFCs and create an operation that can take the header information from a HTCPCP request and transform it into a FHIR appropriate request to a Device with full use of the http status codes needed for processing.

Deviations from IETF RFC 2324 and RFC 7168

IETF RFC 7168 adds the addition-type of “sugar-type” without a significant differentiation from the RFC 2324 addition-type of sweetener-type with the note:

It has been observed that some users of blended teas have an occasional preference for teas brewed as an emulsion of cane sugar with hints of water.
To allow for this circumstance, the Accept-Additions header field defined in the base HTCPCP specification is updated

This information is duplicative for the purposes of FHIR and a sugar-type additive type is coded within BrewedBeverage Profile.

In addition, IETF RFC 2324 does not make allowances for decaffeinated beverages to be requested due to a lack of point. To support this, the BrewedBevarage Profile added a parameter element decaffeinated with the with the only acceptable term of “No”. Any attempt to add decaffeinated versions of coffee and/or tea to the BrewedBeverage.beverageSubType CodeableConcept list is a violation of the RFC and subject to invalidation by the Device receiving the BrewedBeverage resource.

Additions Processing

As per RFC 7168:

Services that implement the Accept-Additions header field MAY return a 403 status code for a BREW request of a given variety of tea, if the service deems the combination of additions requested to be contrary to the sensibilities of a consensus of drinkers regarding the variety in question.

This processing requirement is expressed within the FHIR context via the BrewedBeverage.additions[x] elements. Sufficient processing to enforce this requirement shall be dedicated and policy would dictate the conditions that would require the return of the 403 status error. As with RFC 7168, determination of the most viable combinations of additions for each variety to be served is outside the scope of the BrewedBeverage specification.

Error Codes Specific to BrewedBeverage

RFC 2324 declares two specific Error states defined due to device capabilities:

Error	Definition
406 Not Acceptable	This return code is interpreted as “The Device identified by the request is only capable of generating response entities which have content characteristics not acceptable according to the elements sent in the request.”
418 I’m a Teapot	Any attempt to brew coffee with a teapot should result in the error code “418 I’m a teapot”. The resulting response definition MAY be short and stout.