FHIRPath with extension token fails with function error and throws an exception - request for support of extension

[coline14s]

Q: Does fhirpathy support “extensions”
I think it does since when I do this search on the test subdirectory, I get a number of test cases with extension examples. When i run my evaluates, i get exceptions inside my try loop for these examples.

TEST 1:
These FHIRPath:
ExplanationOfBenefit.extension('https://bluebutton.cms.gov/resources/variables/dsh_op_clm_val_amt').valueMoney.value
ExplanationOfBenefit.billablePeriod.extension('https://bluebutton.cms.gov/resources/variables/claim_query_cd').valueCoding.code

Throw an exception for the attached ExplanationOfBenefit FHIR Resource. I know the extension does not exist for the EOB examples, but should the evaluate throw an exception?

TEST 2:
This FHIRPath fails when run against the patient resource attached (in zip). Same question except this path seems like it should work, the extension is inside the identifier coding.

Patient.identifier.where(type.coding.extension('https://bluebutton.cms.gov/resources/codesystem/identifier-currency').valueCoding.code = 'current').where(system = 'http://hl7.org/fhir/sid/us-mbi').value

jsonFiles.zip

Any help is appreciated!
Thanks

[coline14s]

Believe that the presence of the token "extension" in the FHIRPath generates a exception. This issue was created to confirm that this is the expected behavior please. Thanks

FYI - Here were all my FHIRPaths that created an exception for the resources attached above:
ExplanationOfBenefit.billablePeriod.extension('https://bluebutton.cms.gov/resources/variables/claim_query_cd').valueCoding.code
ExplanationOfBenefit.extension('https://bluebutton.cms.gov/resources/variables/ime_op_clm_val_amt').valueMoney.value
ExplanationOfBenefit.extension('https://bluebutton.cms.gov/resources/variables/ime_op_clm_val_amt').valueMoney.value
ExplanationOfBenefit.extension('https://bluebutton.cms.gov/resources/variables/dsh_op_clm_val_amt').valueMoney.value
ExplanationOfBenefit.extension('https://bluebutton.cms.gov/resources/variables/clm_mdcr_non_pmt_rsn_cd').valueCoding.code
ExplanationOfBenefit.extension('https://bluebutton.cms.gov/resources/variables/clm_uncompd_care_pmt_amt').valueMoney.value
ExplanationOfBenefit.facility.extension('https://bluebutton.cms.gov/resources/variables/clm_fac_type_cd').value.code
ExplanationOfBenefit.extension('https://bluebutton.cms.gov/resources/variables/clm_srvc_clsfctn_type_cd').valueCoding.code
Patient.identifier.where(type.coding.extension('https://bluebutton.cms.gov/resources/codesystem/identifier-currency').valueCoding.code = 'current').where(system = 'http://hl7.org/fhir/sid/us-mbi').value

[coline14s]

Reduced my example to a single test - confirmed that extension is not supported in the release i installed through pip, but wondered if there is a new version with support for extension.

Error
Exception has occurred: Exception
Not implemented: extension
File "/Users/colinwearring/code/pyFiles/fhirpathpy _evaluate.py", line 195, in
result = evaluate(patient, "Patient.identifier.where(type.coding.extension('https://bluebutton.cms.gov/resources/codesystem/identifier-currency').valueCoding.code = 'current').where(system = 'http://hl7.org/fhir/sid/us-mbi').value", [])
Exception: Not implemented: extension

Attached simple test case.
fhirpathpy _evaluate.py.zip

[ir4y]

Hi @coline14s

Thank you for your contribution. Unfortunately extension is not implemented yet.
I will have a look at it next week and most likely implement and release a new version.

[ir4y]

@coline14s the simple implementation that works for your case is done.
Please feel free to install it from github.

However extension on primitive types is not supported yet, this part is WIP #22
The new version of the library will be released once primitive types will be supported.

[ir4y]

@coline14s new version 0.2.1 with extension support has been released.

[coline14s]

thanks ir4y - really appreciated - we're using in a demonstration at the CMS FHIR Connectathon, so if extension works for that example, it will make an excellent impression. testing now.

[coline14s]

Tested and works like a champ! Really great outcome! Can't thank you enough.
Here's our track if folks are interested:
https://confluence.hl7.org/display/FHIR/2023+-+07+CMS+BCDA%2C+AB2D+and+DPC+Introduction+and+Workshop+-+Connectathon+2023-07