Validate Operation : Overview

In the store profiles in Azure API for FHIR article, you walked through the basics of FHIR profiles and storing them. This article will guide you through how to use $validate for validating resources against profiles. Validating a resource against a profile means checking if the resource conforms to the profile, including the specifications listed in Resource.meta.profile or in an Implementation Guide.

$validate is an operation in Fast Healthcare Interoperability Resources (FHIR®) that allows you to ensure that a FHIR resource conforms to the base resource requirements or a specified profile. This operation ensures that the data in Azure API for FHIR has the expected attributes and values. For information on validate operation, visit HL7 FHIR Specification. Per specification, Mode can be specified with $validate, such as create and update:

• create: Azure API for FHIR checks that the profile content is unique from the existing resources and that it's acceptable to be created as a new resource.
• update: Checks that the profile is an update against the nominated existing resource (that is no changes are made to the immutable fields).

There are different ways provided for you to validate resource:

• Validate an existing resource with validate operation.
• Validate a new resource with validate operation.
• Validate on resource CREATE/ UPDATE using header.

Azure API for FHIR will always return an OperationOutcome as the validation results for $validate operation. Azure API for FHIR service does two step validation, once a resource is passed into $validate endpoint - the first step is a basic validation to ensure resource can be parsed. During resource parsing, individual errors need to be fixed before proceeding further to next step. Once resource is successfully parsed, full validation is conducted as second step.

Validating an existing resource

To validate an existing resource, use $validate in a GET request:

GET http://<your Azure API for FHIR base URL>/{resource}/{resource ID}/$validate

For example:

GET https://myworkspace-myfhirserver.fhir.azurehealthcareapis.com/Patient/a6e11662-def8-4dde-9ebc-4429e68d130e/$validate

In this example, you're validating the existing Patient resource a6e11662-def8-4dde-9ebc-4429e68d130e against the base Patient resource. If it's valid, you'll get an OperationOutcome such as the following code example:

{
    "resourceType": "OperationOutcome",
    "issue": [
        {
            "severity": "information",
            "code": "informational",
            "diagnostics": "All OK"
        }
    ]
}

If the resource isn't valid, you'll get an error code and an error message with details on why the resource is invalid. An example OperationOutcome gets returned with error messages and could look like the following code example:

{
    "resourceType": "OperationOutcome",
    "issue": [
        {
            "severity": "error",
            "code": "invalid",
            "details": {
                "coding": [
                    {
                        "system": "http://hl7.org/fhir/dotnet-api-operation-outcome",
                        "code": "1028"
                    }
                ],
                "text": "Instance count for 'Patient.identifier.value' is 0, which is not within the specified cardinality of 1..1"
            },
            "location": [
                "Patient.identifier[1]"
            ]
        },
        {
            "severity": "error",
            "code": "invalid",
            "details": {
                "coding": [
                    {
                        "system": "http://hl7.org/fhir/dotnet-api-operation-outcome",
                        "code": "1028"
                    }
                ],
                "text": "Instance count for 'Patient.gender' is 0, which is not within the specified cardinality of 1..1"
            },
            "location": [
                "Patient"
            ]
        }
    ]
}

In this example, the resource didn't conform to the provided Patient profile, which required a patient identifier value and gender.

If you'd like to specify a profile as a parameter, you can specify the canonical URL for the profile to validate against, such as the following example for the HL7 base profile for heartrate:

GET https://myAzureAPIforFHIR.azurehealthcareapis.com/Observation/12345678/$validate?profile=http://hl7.org/fhir/StructureDefinition/heartrate

Validating a new resource

If you'd like to validate a new resource that you're uploading to Azure API for FHIR, you can do a POST request: The server will always return an OperationOutcome as the result.

POST http://<your Azure API for FHIR base URL>/{Resource}/$validate

For example:

POST https://myAzureAPIforFHIR.azurehealthcareapis.com/Patient/$validate

This request will validate the resource. On validation resources are not created in FHIR service, you will need to send a POST request without $validate to create resource.

Validate on resource CREATE/ UPDATE using header.

By default, Azure API for FHIR is configured to opt out of validation on resource Create/Update. This capability allows to validate on Create/Update, using the x-ms-profile-validation header. Set `x-ms-profile-validation' to true for validation.

{
   "FhirServer": {
      "CoreFeatures": {
            "ProfileValidationOnCreate": true,
            "ProfileValidationOnUpdate": false
        }
}

Next steps

In this article, you learned how to validate resources against profiles using $validate. To learn about the other Azure API for FHIR supported features, see

FHIR® is a registered trademark of HL7 and is used with the permission of HL7.