Wow, I didn't know about this (and I have seen it exists since 2018 version 😅). I will try it, thank you very much for your recomendation!

Probably this is the point. We use BPL and we get the stream assigning it as you said. We will check our code to change it as you recommend. Thanks!

Sure! FHIRCraft is built using InterSystems IRIS for Health and works through an interoperability production.

When you send a request (e.g. from the web UI), it goes through a REST service that transforms the input JSON into an IRIS message. From there, a business process handles the generation logic. Depending on the configuration, it can reuse existing resources from a FHIR repository or generate new ones.

The generated resources (like Patient, Observation, etc.) are optionally posted back to a FHIR server — either the default IRIS repository or any external one via REST.

It’s modular and easy to extend with new resource types. If you're curious, I wrote a short technical walkthrough here 😉

Wow, thank you very much for this full explanation!! Now I understand better how BPL's work 😊

Thank you very much for the tip, it works!

I reuse object that I get on first transformation and I transform it to another object, after a call.

This is the BPL that I use:

Class test.bp.TestProcess Extends Ens.BusinessProcessBPL
{

Storage Default
{
<Type>%Storage.Persistent</Type>
}

/// BPL Definition
XData BPL [ XMLNamespace = "http://www.intersystems.com/bpl" ]
{
<process language='objectscript' request='Ens.Request' response='Ens.Response' height='2100' width='2000' >
<context>
<property name='dataRsp' type='test.msg.GetDataResponse' instantiate='0' />
<property name='patient' type='HS.FHIR.DTL.vR4.Model.Resource.Patient' instantiate='0' />
<property name='fhirRsp' type='test.msg.SendResponse' instantiate='0' />
<property name='otherPatient' type='HS.FHIR.DTL.vR4.Model.Resource.Patient' instantiate='0' />
</context>
<sequence xend='200' yend='800' >
<code name='LOGASSERT 1' xpos='200' ypos='250' >
<![CDATA[ $$$LOGASSERT("1. Get data")]]>
</code>
<call name='GetData' target='TestBo' async='0' xpos='200' ypos='350' >
<request type='test.msg.GetDataRequest' >
</request>
<response type='test.msg.GetDataResponse' >
<assign property="context.dataRsp" value="callresponse" action="set" languageOverride="" />
</response>
</call>
<code name='LOGASSERT 2' xpos='335' ypos='600' >
<![CDATA[ $$$LOGASSERT("2. Transform to FHIR")]]>
</code>
<transform name='Transform 1' class='test.dtl.DataToPatient' source='context.dataRsp' target='context.patient' xpos='335' ypos='700' />
<code name='LOGASSERT 3' xpos='335' ypos='800' >
<![CDATA[ $$$LOGASSERT("3. Send to FHIR Repo 1")]]>
</code>
<call name='Send to FHIR Repo 1' target='TestBo' async='0' xpos='335' ypos='900' >
<request type='test.msg.SendRequest' >
<assign property="callrequest" value="##class(test.Util).generatePostFHIRReq(context.patient)" action="set" languageOverride="" />
</request>
<response type='test.msg.SendResponse' >
</response>
</call>
<code name='LOGASSERT 4' xpos='470' ypos='1150' >
<![CDATA[ $$$LOGASSERT("4. Transform to FHIR again (for other repo)")]]>
</code>
<!-- <transform name='REPEAT: Transform 1' class='test.dtl.DataToPatient' source='context.dataRsp' target='context.patient' xpos='335' ypos='700' /> -->
<transform name='Transform 2' class='test.dtl.DataToOtherPatient' source='context.patient' target='context.otherPatient' xpos='470' ypos='1350' />
<code name='LOGASSERT 5' xpos='470' ypos='1450' >
<![CDATA[ $$$LOGASSERT("5. Send to FHIR Repo 2")]]>
</code>
<call name='Send to FHIR Repo 2' target='TestBo' async='0' xpos='470' ypos='1550' >
<request type='test.msg.SendRequest' >
<assign property="callrequest" value="##class(test.Util).generatePostFHIRReq(context.otherPatient)" action="set" languageOverride="" />
</request>
<response type='test.msg.SendResponse' >
</response>
</call>
</sequence>
</process>
}

}

There is a commented line. If I activate this line (basically, repeat first transformation), then everything works.

The generatePostFHIRReq method:

ClassMethod generatePostFHIRReq(fhir As HS.FHIR.DTL.vR4.Model.Base.DomainResource) As test.msg.SendRequest
{
	#dim fhirReq As test.msg.SendRequest
	
	set fhirReq = ##class(test.msg.SendRequest).%New()
	set fhirReq.url = "/"_fhir.resourceType
	set fhirReq.body = ##class(%Stream.GlobalCharacter).%New()
	do fhirReq.body.Write(fhir.ToJSON().Read())
	
	return fhirReq
}

What I need is to send a FHIR resource to 2 different FHIR repositories. And for the second one I need to change some properties from de first transformation. I want to reuse the object obtained in first transformation, because sometimes the resource fot both FHIR repositories is the same.

I have to convert the public key from pkcs#8 to pkcs#1. I have followed this article:

https://community.intersystems.com/post/format-public-key-when-using-rsaencrypt-method-systemencryption-or-systemencryptionrsaencrypt

Now I can encrypt the string, but the service returns that the api_key must be given in the request. I almost have it.

I have checked that question, but I don't understand what happens.

Finally I have used this instruction "openssl rsautl -in fileIn.txt -out fileOut-enc.txt -pubin -inkey public.key -encrypt" using $ZF(-100) and having OpenSSL installed on the server and it works.

I want to do it with Encryption methods, there must be a way to do this with COS and not using shell instructions, right?

Sorry, I got the error with RSAGetLastError(). Is this:

error:0906D06C:PEM routines:PEM_read_bio:no start line;

Thank you very much for your answer. I don't know what algorithm uses openssl_public_encrypt.

I've tried this:

set json = "{""api_key"":""XXXXX"", ""id"":""1""}"
set file = ##class(%FileCharacterStream).%New()
set file.Filename = "public.key"
set key = file.Read(file.Size) 
set jsonEncrypt = $System.Encryption.RSAEncrypt(json, key)

But it doesn't work, it returns an empty string. I try to see the error using RSAGetLastError() and I don't get anything. The public.key has this format:

-----BEGIN PUBLIC KEY-----
......
......
......
......
-----END PUBLIC KEY-----

The line breaks are LF and it is in UTF-8. What format should the public key be in order to work in Ensemble? I am doing something wrong?

Thank you very much! I have tested this, and it's easier to create the full structure with this. This is very useful to us

Thank you very much, it works now!