Lesson 01.02
JSON, XML & primitive rules
Read and troubleshoot FHIR instances in both official wire formats.
Real-World Example
One phone number is still an array
Patient.telecom is 0..*. Even a single phone contact is represented as an array in JSON.
What You Will Learn
- Recognize repeating and choice elements
- Apply JSON primitive and XML ordering rules
- Use resourceType and the FHIR XML namespace
Step-by-Step Explanation
Read the definition first
A maximum cardinality of * means JSON must use an array, even when one value is present. A choice such as effective[x] becomes effectiveDateTime or effectivePeriod.
Apply format rules
JSON uses resourceType and native JSON primitive values. XML uses the FHIR namespace, lower-camel element names, value attributes for primitives, and specification order.
Separate narrative from data
DomainResource.text is human-readable XHTML. Implementers must not treat narrative as a replacement for computable elements.
Inspect and practice
"telecom": [{ "system": "phone", "value": "+1-416-555-0100" }]Key Concept / Interview Takeaway
Cardinality determines the container; the number of values in today’s instance does not.
Loading 10 questions
Ask your instructor
JSON, XML & primitive rules
Only you and the authorized instructor can view this conversation. Other learners cannot see your messages. Do not include patient information, passwords or payment details.
Loading private conversation...