Working With Annotations

Node Trees

The Translator uses Node Trees to store parsed hierarchical data like HL7 and XML messages, and database query results. These are displayed in dialogs using a simple hierarchy, that can be expanded/contracted to show more or less detail as needed.

For example an HL7 message is received as plain text and then parsed into a node tree:

Screen Shot 2014-05-07 at 18.01.33

The node tree is much simpler to understand and work with than the original text format. Simply click on a little “horizontal arrow” to expand a node.

Here we have expanded the MSH segment:

Screen Shot 2014-05-07 at 18.08.37

By default only  nodes with data are shown, but the node tree is “smart” it knows the structure of the HL7 message, which it derives from the supplied VMD file. If you check Show Empty Nodes, it will also display the empty HL7 message fields (this can be very useful when you are mapping data for “partial” messages).

Here are some of the empty fields in this MSH segment:

Screen Shot 2014-05-07 at 18.14.57

Database query results and XML use node trees, but with different icons:

Screen Shot 2014-05-08 at 08.00.32

Screen Shot 2014-05-08 at 08.10.01

Tip: See Node Types for Iguana Node Trees for details of the icons for the different types of node trees

Finally a word about Lua tables and JSON trees, these are not node trees, but they are displayed are displayed hierarchically.

This is what a Lua table or a JSON tree looks like:

Screen Shot 2014-05-08 at 08.17.25

Note: Lua table and the JSON tree are identical because JSON trees are stored in Lua tables.

Leave A Comment?