The name property is  Property name As HS.FHIRModel.R4.SeqOfHumanName; and the SeqOfHumanName class have  Property list As %Library.DynamicArray;
This list property holds the object of  HS.FHIRModel.R4.HumanName

Hello @Scott Roth 

I directly import JSON via fromDao method and It works for me. Did you get any errors while importing?

Set patient = {"resourceType":"Patient","id":"example","text":{"status":"generated","div":"<div xmlns=\"http://www.w3.org/1999/xhtml\">John Doe</div>"},"identifier":[{"use":"usual","type":{"coding":[{"system":"http://terminology.hl7.org/CodeSystem/v2-0203","code":"MR","display":"Medical Record Number"}]},"system":"http://hospital.smarthealth.org","value":"123456"}],"active":true,"name":[{"use":"official","family":"Doe","given":["John"]}],"telecom":[{"system":"phone","value":"+1 555-123-4567","use":"mobile"},{"system":"email","value":"john.doe@example.com","use":"home"}],"gender":"male","birthDate":"1980-01-01","address":[{"use":"home","line":["123 Main Street"],"city":"Anytown","state":"CA","postalCode":"90210","country":"USA"}]}
Set r4Patient = ##class(HS.FHIRModel.R4.Patient).fromDao(patient)
Write r4Patient.toString()

In the above example, the list property holds a %DynamicObject value, not a string literal. Therefore, you can use DAO (Dynamic Access Object) methods to work with it. However, if you're using the latest IRIS version (2023.2 or later), you can also use the apply method to retrieve the family and given fields directly from the %DynamicObject.

Version 2024.1

Write r4Patient.name.list.apply("$[*].family").%ToJSON()
write r4Patient.name.list.apply("$[*].given").%ToJSON()

For older versions that do not support the apply method, you can use traditional JSON access techniques:

/// loop by size
for i=0:1:r4Patient.name.list.size()-1 {
    Set humanName = r4Patient.name.list.%Get(i)
    Write humanName.family_"  "_humanName.given
}

Using an iterator:

/// By iterator
Set iter = r4Patient.name.list.%GetIterator()
While iter.%GetNext(,.humanName) {
    Write humanName.family_"  "_humanName.given
}

Sample code for the human name testing

ClassMethod FHIRHunmanNameTest()
{
    Set r4Patient = ##class(HS.FHIRModel.R4.Patient).%New()
    ;
    Set seqHuman = ##class(HS.FHIRModel.R4.SeqOfHumanName).%New()
    Set human = ##class(HS.FHIRModel.R4.HumanName).%New()
    Set human.family="pil"
    Set human.text="Ashok,kumar"
    ;
    Set human1 = ##class(HS.FHIRModel.R4.HumanName).%New()
    Set human1.family="pil"
    Set human1.text="Ashok,kumar"
    ;
    ; seq string
    Set seqString = ##class(HS.FHIRModel.R4.SeqOfString).%New()
    Set seqString.list=["ashok","kumar"]
    ;
    Set human1.given=seqString
    ;
    Do seqHuman.add(human.toDao())
    Do seqHuman.add(human1.toDao())
    
    Set r4Patient.name = seqHuman
    
    Set iter = r4Patient.name.list.%GetIterator()
    
    While iter.%GetNext(,.humanName) {
        Write humanName.family_"  "_humanName.given
    }
        
    For i=0:1:r4Patient.name.list.size()-1 {
        Set humanName = r4Patient.name.list.%Get(i)
        Write humanName.family_"  "_humanName.given
    }
    Write r4Patient.name.list.apply("$[*].family").%ToJSON(),!
    Write r4Patient.name.list.apply("$[*].given").%ToJSON()
}

Hello @Corentin Blondeau

Here is the code to retrieve the properties in the same order they are defined in the class.

ClassMethod GetPropOnDefinedSequence(pClass As %String = "", Output pProperties)
{
	For {
		Set property=$$$comMemberNext(pClass,$$$cCLASSproperty,property)
		If property="" Quit
		If property="%%OID"!(property="%Concurrency") continue
		Set pProperties(
			    +$$$defMemberKeyGet(pClass,$$$cCLASSproperty,property,$$$cPROPsequencenumber),
			    property)=""
	}
	Return $$$OK
}

 The properties assigned to the pProperties parameter

Hello @Scott Roth 

The  HS.FHIRModel.R4.SeqOfHumanName has property "list" which is %DynamicArray. So, If you access via object r4Patient.name.list.%Get(0) for get 0 index value $ZCVT(r4Patient.name.list.toString(),"I","JSON") get entire value. Here r4Patient is a object of HS.FHIRModel.R4.Patient 

FHIRDEV>Write r4Patient.name.list.%Get(0)
{"use":"official","text":"Ashok,Kumar"}
FHIRDEV>Write $ZCVT(r4Patient.name.list.toString(),"I","JSON")
["{"use":"official","text":"Ashok,Kumar"}","{"text":"Ashok,Kumar"}"]
FHIRDEV>Write $ClassName(r4Patient)
HS.FHIRModel.R4.Patient

Thank you!

Hello @Evgeny Shvarov

Unfortunately, when the %JSONFIELDNAME parameter is not explicitly defined, the JSON adaptor treats the property name as a constant, making it fixed and case-sensitive.

However, you can define a custom mapping using an XData block to control how properties are mapped to JSON fields. This provides greater flexibility, and you can even use both %JSONFIELDNAME and XData mappings within the same class.

Example: Custom Mapping with XData

XData OnlyLowercaseTopLevel
{
  <Mapping xmlns="http://www.intersystems.com/jsonmapping">
    <Property Name="Name" FieldName="eventName"/>
    <Property Name="Location" Include="INPUTONLY"/>
  </Mapping>
}

• Do obj.%JSONImport(dao) Default import (uses standard property names)
• Do obj.%JSONImport(dao, "OnlyLowercaseTopLevel")Import using a custom mapping

Index ZipIDX On ZipCode [ Data = (City, State) ];

Here, the index is built on the ZipCode field, and the City and State fields are included in the Data portion of the index structure (i.e., stored as part of the index global). When a query retrieves only City and State based on a ZipCode filter, the SQL engine can perform an index-only scan and avoid accessing the main "Master map". This behavior is similar to a covering index in SQL databases because the requested data is fully available within the index itself.

SELECT City, State FROM Sample.Person WHERE ZipCode = 19904;

In this case, the index global might look like:

^gblI("ZipIDX", ZipCode, ID) = $LB("", City, State)

The query will be satisfied using just the index, avoiding a full table (master map) access.

However, this index does not provide any benefit when the query uses City or State as filter conditions, since those fields are not part of the index key. So, It will search on the "Master map"

Now, consider another index:

Index CityStateIDX On (City, State);

This is a composite index (or multi-column index), where both City and State are stored as part of the index key (subscripts), not as index data. The global would look like:

^gblI("CityStateIDX", City, State, ID) = "

SELECT state FROM SAMPLE.PERSON1 WHERE city ='Newton'

When a query uses City or State in the WHERE clause, the index is used to locate the matching IDs, but the SQL engine must then perform a lookup in the master map to fetch any other columns, even if you're selecting only indexed fields like City or State.

So, composite indexes help filter rows efficiently, but they don't function like covering indexes unless the query involves only index keys and you don't need to retrieve other columns.

Here is the Index types documentation

Thank you, @Dmitry Maslennikov, for your incredible journey and inspiring contributions to the community. Wishing you continued success and endless learning ahead!