What are the rules for a valid variable name in mirth?

Question

I am trying to set up a transformer on a Database Reader to file writer channel. I am reading in a sql field called MRN which I would like to send to a variable called mrn. I added a step to a channel with a variable called tmp['MSH'] mapping to a variable called msg['MSH'] But mirth is giving me the error message:

The variable name contains invalid characters. Please enter a new variable name

What are the rules for a valid variable name in mirth?

Answer 1

tmp and msg are two built-in variables containing E4X mappings of the outbound template and inbound message, respectively. You would map, via a MessageBuilder step, from inbound to outbound with tmp['MSH'][...] = msg['MSH']... where ... refers to the appropriate sections. Essentially these are pre-populated javascript property arrays.

If you really want to create a variable for use in multiple places, the rules are alphanumeric plus '_', I believe.

In a MessageBuilder step, you could refer to a previously created variable with ${varname}.

I would recommend investing a little time in getting familiar with the basics. Documentation is wanting, to be sure, but this blog post series are a good place to start.