Remove a segment from the HL7 Message

Question

Question

ED Coder · Jul 31, 2019

#HL7 #Ensemble

Hi,

I have a ORU message, which has a EVN segment that I want to remove and send the message across.

I tried to clone the request as below:

s newreq = request.constructClone

s changreq = newreq.RemoveSegmentAt("EVN")

Set request = changereq

but it fails. Is there a way that I can safely remove a segment and pass it on?

Would appreciate your help in this

Regards,

Eric

Discussion (13)1

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ED Coder · Aug 8, 2019

Was able to solve this by the following code.

//create a copy of the request
s newREQ = request.%ConstructClone()
s ind = ""
s EVNSeg = newREQ.FindSegment("EVN",.ind)
if EVNSeg '= ""
{
s res = newREQ.RemoveSegmentAt(ind)
}

s request = newREQ

Quit request

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score 0 · Answer 1 · 2019-07-31T12:15:11-04:00

The method RemoveSegmentAt returns a status, not the message with the segment removed.

So your HL7 message with the EVN removed is still "newreq" and it is this that you want to pass on.

score 0 · Answer 2 · 2019-08-01T03:31:07-04:00

ED Coder · Aug 1, 2019

Hi Julian, thank you for pointing that out to me. Can you advice how I can remove that segment?

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score 0 · Answer 3 · 2019-08-05T02:44:41-04:00

Julian Matthews · Aug 5, 2019

Thanks Jeff, that's a better articulation of what I originally tried to say.

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score 0 · Answer 4 · 2019-08-08T05:30:58-04:00

Hi Jeff, I tried that, but I am losing the rest of my message. I must be doing something wrong. Can you advice? Following is the error I am getting once I remove segment and pass the messsage

score 0 · Answer 5 · 2019-08-01T03:50:14-04:00

Personally, I would use a DTL which removes the EVN, and then I would call the DTL class from objectscript:

Set tSC=$CLASSMETHOD("DEV.Transformations.DUMMY.A01toA01","Transform",request,.messageWithoutEVN)

So, "Transform" in quotes is the action, request is your original Enslib.HL7.Message coming in, and .messageWithoutEVN is the output from your DTL.

Does that help?

score 0 · Answer 6 · 2019-08-02T04:59:47-04:00

the message coming in is an ORU_R01 message, and contains an EVN segment, however in the schema 2.4 there is no EVN segment in the ORU message structure. so how can I remove the segment, is there a way to do that? Sorry for the hassle.

I want to pass this message to the third party system having the EVN segment removed. Will keep trying but if you have any ideas would apprecaite.

Thank you

score 0 · Answer 7 · 2019-08-08T12:56:00-04:00

I would expect to see that error on the original message (before the EVN segment was deleted) but not on the cloned/modified version. Are you sure you're looking at the right message?

score 0 · Answer 8 · 2019-08-09T05:51:06-04:00

Yes Jeff, I was looking at the cloned message that was sent across. I removed by index now, and it works. so looking good. Thank you so much for guiding me on this

score 0 · Answer 9 · 2019-08-09T06:27:41-04:00

Ah, now it makes sense. The Document type you'd specified for the inbound message did not match the structure of the message itself, so the RemoveSegmentAt() method didn't know how to "find" the EVN segment ... it didn't exist in that schema.

The recommended approach would be to use a schema/document type (custom if necessary) that matches the structure of your inbound message, making the segment to be removed optional in the definition. With that in place, the RemoveSegmentAt() method would have worked as expected.

score 0 · Answer 10 · 2019-08-14T07:10:30-04:00

You are spot on Jeff. Yes, I was thinking if I should update the schema.. but didnt do it. The message we are getting is an ORU_01 but has the EVN segment. Thank You, now I know what caused my issue too.

score 0 · Answer 11 · 2019-08-02T06:56:49-04:00

You were close with you original code ...

Set newreq = request.%ConstructClone()

Set sc = newreq.RemoveSegmentAt("EVN")

Set request = newreq

the variable sc is the status of the remove segment operation; the EVN segment is actually removed from newreq.

score 1 · Answer 12 · 2023-08-24T05:44:39-04:00

Hello @ED Coder,

you can also use a "low-code" approach using the DTL language with the REMOVE action :

Class utils.HL7.transfo.removeSegment Extends Ens.DataTransformDTL [ DependsOn = EnsLib.HL7.Message ]

{
Parameter IGNOREMISSINGSOURCE = 0;
Parameter REPORTERRORS = 1;
Parameter TREATEMPTYREPEATINGFIELDASNULL = 0;
XData DTL [ XMLNamespace = "http://www.intersystems.com/dtl" ]
{
<transform sourceClass='EnsLib.HL7.Message' targetClass='EnsLib.HL7.Message' sourceDocType='2.6:ADT_A01' targetDocType='2.6:ADT_A01' create='copy' language='objectscript' >
<assign value='' property='target.{EVN}' action='remove' />
<assign value='' property='target.{DG1()}' action='remove' />
</transform>
}
}