HL7 File Feeder

Say you have a text file with a bunch of HL7 messages. Each segment ends with \r. And each message ends with \n. Here’s the file attached:

You could use the simulator component and feed it in via an HL7 Server - but honestly it’s probably easier to write you own little component and feed the data directly into the component you are testing.

Use a custom field for the input file name

See Custom Fields Here we use ~/test.txt for the default location of the input file.

You access that with:

local FileName = component.fields()

Read in the file using the FIL library with FILread

The FIL library makes it really easy to inhale the file:

local Content = FILread("main.lua");

Examine the file contents in the translator - each segment ends in \r but the message ends with \n characters

We can easily see by looking at the contents of the file using the Escaped Text mode:

Then we split the contents on the \n with local List = Content:split("\n")

See String:split(). So now our code looks like this:

require "FIL.FILreadWrite"

function main(Data)
   local F = component.fields().InputFile
   trace(F)
   local Content = FILread(F)
   local List = Content:split("\n")
   trace(#List)   
end

In the editor it looks like:

By double clicking of the list coming back we can we the list of messages:

With a for loop we can push these messages into the queue:

See Lua tables as lists

for i=1, #List do
   queue.push{data=List[i]}
end

And now we have a working test component!

Connect it the component we want to test with - done!

See Linking components if you need a refresher.

Now for a little extra flourish:

Add some custom logging

Let’s add some Custom Logging

Just added lines 7 and 11 to the script:

function main(Data)
   local F = component.fields().InputFile
   trace(F)
   local Content = FILread(F)
   local List = Content:split("\n")
   trace(#List)  
   iguana.logInfo("#start About to queue "..#List.." messages");
   for i=1, #List do
      queue.push{data=List[i]}
   end
   iguana.logInfo("#end Finished queueing "..#List.." messages");
end

Now we we run the script we can see custom logging:

And some custom status

See Custom Status

require "FIL.FILreadWrite"

function Status(N, Total)
   component.setStatus{data="Sending "..N.." of "..Total}  
end

function StatusDone(Total)
   component.setStatus{data="Completed sending "..Total.." messages."}
end

function main(Data)
   local F = component.fields().InputFile
   trace(F)
   local Content = FILread(F)
   local List = Content:split("\n")
   trace(#List)  
   iguana.logInfo("#start About to queue "..#List.." messages");
   for i=1, #List do
      Status(i, #List)
      queue.push{data=List[i]}
   end
   StatusDone(#List)
   iguana.logInfo("#end Finished queueing "..#List.." messages");
end

Like a copy of the code?

The repository is here:

https://bitbucket.org/interfaceware/feeder/src/main/ - Git URL is git@bitbucket.org:interfaceware/feeder.git

See Create component from Git URL

Couple of videos showing the component in action

This shows using the component and the internals:

internals.mp4

And this one shows using the logs from the component:

logs.mp4

And now we have a simple tool that makes it easy to test our HL7 interfaces. But more importantly this exercise puts together a set of little concepts that once you grasp you can solve not only simple problems, but you can build up the skills to be able solve complex ones as well. There are no bottlenecks you cannot remove.