[HAPI-devel] Validate messages

[Lorenzo V. <Lor...@ev...>]

Hi at all.

I need some help to better understand how to validate the length of the fields and sub-fields in a HL7 message.
Below, an example

MSH|^~\&|ADT|MEDARCHIVER|CDE|EXPRIVIA|20160624152026||ADT^A13|2503431|P|2.5
EVN||20160624152026
PID|||81041214^^^X1V1_MPI^PI||TEST^ALBA^^^^^L^^^^^^^LICENZA ELEMENTARE||19950919|F|||&gg^^GABIANO^AL^15020^100^L^006077^ITALIA~&gg^^GABIANO^AL^15020^100^H^006077^ITALIA~^^ABANOTERME^PD^^100^BDL^028001^ITALIA||^PRN^CP^^^^^^^^^064534534534~^ORN^CP~^NET|||||||||||||100^ITALIA
PV1||I|10121^STANZA01^LETTOA^2.16.840.1.113883.2.9.3.120915^^^^^CARDIOLOGIA|1|||||TSTMGP00A01H501G^^^^^^R.1.1^^&2.16.840.1.113883.2.9.4.3.2&ISO||||||||||12345678^2017|||||||||||||||||1||||||||20150625150800|20160622105500||||||||1

Some question about this message:

1)      for the field PID.11.1 (or other fields that can contains the sub-field delimiter), in presence of sub-fields how can I calculate the length of this field? With or without space?

2)      if a field or sub-field contains an escape character (e.g. \T\ or \H\), the rule for calculate the length of the field must consider only the escape character itself without the backslash?

3)      if a field or sub-field contains an escape sequence for multiple character, what is the rule for calculate the length of the field?

Thanks at all for your reply.