Create Regex Attachment Handler

[JJWest12]

I am trying to write up a regex attachment handler that removes the final segment from an inbound HL7V2 message. The final segment is always a custom segment with the header "PLY".

My attachment handler regex is PLY.* with a MIME type of text/plain. When running this I can see that the attachment is made and on the end of the raw message on the source, however I get this error below:

TypeError: The content of elements must consist of well-formed character data or markup.

All datatypes on the channel are HL7V2. What am I missing here?

[pacmano1]

sample message. you know better :).

And an hl7 message with a header? What does that mean? You mean a final segment name of "PLY"?

[kirbykn2]

PLY is the segment name. When referring to PLY, MSH, PID, etc I just refer to them as the segment.

"The final segment is a custom segment called "PLY"."

[pacmano1]

I suspect your ask is to add the base64 PDF as an attachment, correct? Meaning from PLY-4, correct? Then remove the PLY segment?

[jonbartels]

The content of elements must consist of well-formed character data or markup.

and

My attachment handler regex is PLY.*

I bet what is happening is that your message is being turned into this:

MSH|^~&|||||20240104073426||MDM^T02^DOC||2.5.1
EVN|T02|20240104073426||UPDATE_NOTE|^^^^^^^^^^^^^
PID|||||^ ***********^^^^^|||M||White| *** ^ ^^^US^P^^|^^||()-^P^H^^^^|()-^P^W^^^^|ENG|MARRIED|||--|||NOT HISPANIC|||||No|||N
PV1||INPATIENT|**^^-^^^^^^^^||||^^^^^^^^^^^^||^^^^^^^^^^^^|Hospitalist|||||||***^^^^^^^^^^^^|||||||||||||||||||HOME|||||||||||****.|||*
OBR|1|||||||^Progress Notes|||||||||||||||||||||F||||||||||
OBX|1|ED|^Progress Notes|1|SEE ATTACHMENT||||||F|||
${ATTACH:d3ad-b33f-0000}

This is not valid HL7 and the parser barfs on it.

You can prove my idea by changing your incoming datatype to RAW. This will get past the parsing error (because it doesnt parse!) and you'll be able to see the incorrect HL7 structure.

Look at "Attachments Using Regex" at https://forums.mirthproject.io/articles/175046-using-attachments . You want a regex like the OBX regex shown in the example. That will make the large base64 encoded blob the attachment, not the whole segment, like this:

OBR|1|||||||^Progress Notes|||||||||||||||||||||F||||||||||
OBX|1|ED|^Progress Notes|1|SEE ATTACHMENT||||||F|||
PLY|||asdf|asdfs|${ATTACH:d3ad-b33f-0000}

[pacmano1]

What @jonbartels said. You can delete the PLY segment though after the attachment is added using the regex, It will be avaiable in the channel even with the PLY segment gone.

[pacmano1]

(?:PLY\|(?:[^|]*\|){3}(?:[^|^]*\^){0})([^|^\r\n]*)(?:[|^\r\n]|$)