how-to-validate-fhir-resources.md

How To Validate FHIR Resources

This guide describes how an application can validate a FHIR object using the API

Javascript

To validate a FHIR object, first determine which version of FHIR you wan to validate against. There are five API endpoints for each endpoint that is possible to validate against. They are:

• POST /fhir/r5/validate
• POST /fhir/r4/validate
• POST /fhir/v2/validate
• POST /fhir/v2_1/validate
• POST /fhir/v3/validate

In this example we'll use the r4 endpoint.

We will be using isomorphic-fetch from npm, go ahead and npm install --save isomorphic-fetch or use your favorite request library.

Successful Validation

Below is an example of a valid FHIR object

const fetch = require('isomorphic-fetch')

const requestBody = {
  resourceType: 'Parameters',
  parameter: [
    {
      name: 'result',
      valueBoolean: true
    },
    {
      name: 'innerPackageSize',
      valueDecimal: 6.7
    },
    {
      name: 'outerPackageSize',
      valueDecimal: 1
    },
    {
      name: 'packageUnitCode',
      valueString: '3'
    },
    {
      name: 'packageUnitDesc',
      valueString: 'Grams'
    }
  ]
}

const validateR4Fhir = async () => {
  return fetch('localhost:5000/fhir/r4/validate', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/fhir+json',
      Accept: 'application/fhir+json'
    },
    body: JSON.stringify(requestBody)
  })
}

validateR4Fhir()
  .then(res => res.json())
  .then(res => {
    console.log(res.body)
  })

Successful Response

With the code above you should see the following response.

{
    "successful": true,
    "errors": [],
    "warnings": [],
    "info": [],
    "exception": null
}

Failed Validation

Here is an example of a failed validation due to the valueBoolean attribute being considered a String

const fetch = require('isomorphic-fetch')

const requestBody = {
  resourceType: 'Parameters',
  parameter: [
    {
      name: 'result',
      valueBoolean: 'true'
    },
    {
      name: 'innerPackageSize',
      valueDecimal: 6.7
    },
    {
      name: 'outerPackageSize',
      valueDecimal: 1
    },
    {
      name: 'packageUnitCode',
      valueString: '3'
    },
    {
      name: 'packageUnitDesc',
      valueString: 'Grams'
    }
  ]
}

const validateR4Fhir = async () => {
  return fetch('localhost:5000/fhir/r4/validate', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/fhir+json',
      Accept: 'application/fhir+json'
    },
    body: JSON.stringify(requestBody)
  })
}

validateR4Fhir()
  .then(res => res.json())
  .then(res => {
    console.log(res.body)
  })

Failed Response

With the code above you should see the following response.

{
    "successful": false,
    "errors": [
        {
            "message": "Error parsing JSON: the primitive value must be a boolean",
            "severity": "ERROR",
            "locationCol": null,
            "locationLine": null,
            "locationString": "/Parameters/parameter/value[x]"
        }
    ],
    "warnings": [],
    "info": [],
    "exception": null
}

Response Analysis

Each response has a top-level successful attribute that determines if the overall validation was successful. Other attributes include errors, warnings, and info which are all arrays that will include more detailed information if available. The final attribute is exception which will be available if the validation was not able to run due to a runtime error.

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