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Colin Brough · Jan 29

With help from WRC, looks like this is something of our own doing - we were using sub-transforms in ways that caused us problems. Our sub-transforms above were outputting whole new XML documents, when at the very least they should have been taking existing partially produced XML from the top-level transform and using that existing document to output. We "solved" the node ordering issue by moving everything into a single transform, so there was no mismatch between top level and sub-transforms.

Colin Brough · Nov 20, 2024

We've got the same issue, but with an incoming HL7 feed with embedded, encoded characters - would be nice to be able to detect what's coming in, but I take it from this discussion that's not (reliably) possible. Don't really want to scan the whole text of every incoming message to heuristically look for possible encodings. Upstream say/think they are sending UTF-8, but we seem to be getting Window-1252, for the characters we've seen in the (limited) testing. Who knows what will come through the feed once it goes live!

Colin Brough · Sep 27, 2024

Auto-adjust / design question 4: we'd find this useful, especially if it handles bulk renames - a bunch of classes implementing a data type, all being moved in one go from one place in the class hierarchy to another and all being consistently renamed.

So files X/Y/A.cls, X/Y/B.cls, X/Y/C.cls, and containing classes X.Y.A, X.Y.B, and X.Y.C being moved to Q/P/A.cls and Q.P.A etc. Especially if Properties defined in X.Y.A as "Property pp As X.Y.B" becomes "Property pp As Q.P.B" when renamed.

Colin Brough · Sep 18, 2024

Closing off an old question for completeness, we never did get Zen working. In the end we used Apache FOP directly:

  • HL7 -> XML as described in the original question
  • call Apache FOP using $ZF(-100,  $$$fopbat, "-xml", XMLfilename, "-xsl", StyleSheetFilename, "-pdf", PDFfilename)

This puts the output PDF onto the filesystem from where, in our solution, it is later picked up for onward transmission to a downstream system.

Colin Brough · Sep 18, 2024

For the sake of closing off this old question, and to answer my own question, in light of more experience and some testing...

  • side effects of the transformation could, in theory, change the behaviour - but it'd have to be a transformation that had side-effects (eg kept some kind of state across executions, whether in globals or on the filesystem or in some other way)
  • performance could be affected, since transformation is called twice rather than once, but in most cases the difference is likely to be negligible.
Colin Brough · Sep 2, 2024

Business Operation is one generated by SOAP Wizard. It is being fed by a custom Business Process that runs in response to a scheduled task - the BP queries a database table and extracts a set of documents to send. At certain points in the day we want to query the table like this:

      SELECT * from TABLE

while at other points in the day we want to query the table like this:

      SELECT TOP NN * from TABLE

Then the documents selected by the query are sent, in turn, to the Business Operation for onward transmission.

Colin Brough · Aug 16, 2024

We have a situation that looks suspiciously similar:

  • job that runs an external program via $ZF(-100,...) to perform a task from a business process runs perfectly when the Pool Size = 1
  • not all of the external tasks complete successfully when Pool Size > 1

More detail:

  • Production takes incoming stream of HL7 ORU_R01 messages, and for each one produces a PDF
  • this is done by converting each HL7 to an XML representation, then calling Apache FOP (the one pre-installed in Ensemble) with a stylesheet and the XML to build the PDF. A business process takes care of this step.
  • with Pool Size = 1 runs correctly
  • with Pool Size = 2 all the XML files are generated (via a call to a class method) but only a small subset of the PDF files are generated - maybe 4 out of 20?
  • no error messages that we've been able to find yet

Here's an illustrative screenshot - yellow are first HL7->XML->PDF, green are second HL7->XML->PDF. Yellow produces a PDF, green doesn't. As far as we can tell the FOP commands should be independent (no shared files - unless stylesheets can't be opened by multiple processes simultaneously?)



Only thing we've seen in documentation that gives us pause is the line: "On a Windows system you should never omit both the /ASYNC and /STDIN flags." (from $ZF(-100) | InterSystems IRIS Data Platform 2024.2) - but when only one copy is running it appears to be fine with "" as the flags argument.

Is this a $ZF/Ensemble issue, or is it something about FOP specifically?

Colin Brough · Jun 27, 2024

Say you have the same code (Production) running on different servers - for example, a local instance on a developers own machine, a test server used for system testing and a production server.

Your code accesses an external web-service. The actual web-service will be different for each system - maybe a mock service for the developer, a test version of the web-service for the test system and a production version for your production server. Then the URL for accessing the web-service would be different for each one.

In your code you have a setting on the business operation in your production that connects to the web-service. The value of this setting can be set from the System Defaults Settings page, and will contain different values between the servers.

This allows you to separate out settings that will be the same across all servers, and settings that will differ between servers - settings that are the same on all servers can be set on the services/processes/operations themselves, settings that differ will be set via system defaults.