Jimmy Christian · Dec 18, 2019

Batch header and footer in Ensemble File Operation

Hello community,

I am receiving a HL7 message over TCP connection.

I have to set up  a process/operation to produce a daily file with this HL7 messages to be created in a directory using EnsLib.File.OutboundAdapter
and EnsLib.HL7.Operation.FileOperation. The file needs to have a header line added each time it is created and a footer .I did not find any standard class file under File Adapter which will create header/footer. 

Any suggestion will be greatly appreciated.


Jimmy Christian

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Are these standard HL7 batch headers and footers (BHS/BTS, FHS/FTS, etc) or something custom to your organization?

If they are one of the HL7 standards, have a look at these docs on HL7 batches:

One tricky part will be triggering when an old batch ends/new batch begins -- this will depend on your local requirements.

If they are custom, there are a few approaches you can consider:

  1. You could use the Record Mapper to define a record map class with header/footer and a single field record for the HL7 content. You would then use one of the  EnsLib.RecordMap.Operation.* classes instead of EnsLib.HL7.Operation.FileOperation: In particular, have a look at RolloverSchedule and/or RolloverLimit to control when a new batch file is created.
  2. If you're comfortable creating a custom class that extends EnsLib.HL7.Operation.FileOperation, you could override the outputDocument method. In your custom version of outputDocument you could check if the file already exists using ##class(%File).Exists(pathToFile) and if it doesn't you would write out the footer to the previous file and the header to the new file before calling the standard version of outputDocument using ##super.

Thank you Marc for the detailed information.

I earlier tried the approach using the Record Mapper but it did not seam feasible in this scenario. 

So i have done is 

Created a CUSTOM operation class which extends Ens.BusinessOperation, EnsLib.HL7.Operation.Standard

It uses the file adapter.

Then I overided the oninit and outputDocument method.

  1. The file adapter creates HL7 file as usual
  2. I created a new method which calls the override outputDocument method and passes the filename . Then I do a count of segments and create another file into which I copy all the necessary information and delete the file which was originaly created .
  3. Above method is called in oninit, so it is triggered on schedule whenever the operation starts. First I check if a file exists, if it does and is not the current file then I call this new method.

We have a similar need.  We have to enclose the HL7 ORU messages within the FHS, BHS, and BTS, and FTS segments (with the counts of the total transactions in the BTS, and FTS segments).

Is writing custom code the only option for this?

Hello Pankaja,

Seems like for now custom code is the only option. I was not able to find any out of the box functionality for writing the counts of the total transactions without a custom code.

Here are few strategies for custom code i looked into.

1) In the File Operation , write the messages to a "Temp" File. At a certain time through a task or some other logic read from the temp file and collect all details you need and then write to another File.

2) I yet have to explore this option. At a point in time when you want your file, read from the Enslib.Hl7.Msg and create a file per your needs.

3) Write the live messages to a temp database. Generate necessary file from it when needed. Delete the messages from the DB and copy it to a Archive DB if needed.

4) As live messages are coming write to a Global and then run a task to create messages from the Globals.


Jimmy Christian.