Extracting HL7 Fields out of File Names with HL7 Soup

Sometimes when generating an HL7 message, the trigger or source of the message is a file that doesn't contain parsable data such as a PDF.  It's a fairly common practice to use the 255 filename characters to include some additional metadata.  This post shows how to access the filename and then how to extract the values.

Integration Host makes accessing the filename very easy.  If you have a Directory scanner the filename is automatically put into a variable for you to use "DirectoryScannerFileName". The value includes the filename and extension, so it's pretty convenient to use if you just want to update the same file, but as we want to use the values, we need to remove the extension and split that metadata out.

To do this I used a Code Transformer with the following code:

//Get the destination message
IHL7Message destinationMessage = (IHL7Message)activityInstance.Message; 

//Get the filename
string fileName = workflowInstance.GetVariable("DirectoryScannerFileName");

//Remove the extension
fileName = System.IO.Path.GetFileNameWithoutExtension(fileName);

//split it by the _ character
string[] values = fileName.Split('_');

//Write the values to their HL7 location.  I've just put them in dummy locations for now, as you can change them
//Note, that to use this the filename must have the correct number of values or you will get an error.
destinationMessage.SetValueAtPath("PV1-19", values[0]);
destinationMessage.SetValueAtPath("PV1-20", values[1]);
destinationMessage.SetValueAtPath("PV1-21", values[2]);

It's pretty straightforward.  You can see that I get the variable with the filename, then remove the extension, followed by splitting it by the "_" character.

Then it's just a matter of placing each value where I want it.  I've put it into the PV1-19 to 21, but you can use whichever location you need.

The one thing to note is that I've written this to error if the number of fields required isn't provided.  I prefer this outcome rather than proceeding even if the filename doesn't have all the values, but others may wish to put an IF condition around it to only add the values if the right number of fields exist.