The GetTREFields method retrieves the fields of selected Tagged Record Extensions (TREs) in a NITF or MIE4NITF file.
Example
e = ENVI(/HEADLESS)
File = FILEPATH('MultiSegmentExample.ntf', ROOT_DIR=e.ROOT_DIR, $
SUBDIRECTORY = ['data', 'NITFExamples'])
NITF = ENVINITF(File)
TREFields = NITF.GetTREFields('Text', 0, 'PIAPEA')
Print, TREFields
Result:
CETAG CEL LASTNME FIRSTNME MIDNME DOB ASSOCTRY
Syntax
Result = ENVINITF.GetTREFields(Type, Index, TREName [, ERROR=value])
Return Value
This method returns a string array of field names.
Arguments
Type
Specify a string with the segment type from which to retrieve TRE names. Strings are not case-sensitive. The choices are:
Header
Image
Text
Or, specify the name of a MIE4NITF camera series; for example: series0, series1, etc.
Index
Specify an integer with the index number of a segment or a frame in a series.
TREName
Specify a TRE name from which to retrieve fields. Use the GetTRENames method to get TRE names.
Keywords
ERROR
Set this keyword to a named variable that will contain any error message issued during execution of this routine. If no error occurs, the ERROR variable will be set to a null string (''). If an error occurs and the routine is a function, then the function result will be undefined.
When this keyword is not set and an error occurs, ENVI returns to the caller and execution halts. In this case, the error message is contained within !ERROR_STATE and can be caught using IDL's CATCH routine. See IDL Help for more information on !ERROR_STATE and CATCH.
See Manage Errors for more information on error handling in ENVI programming.
Version History
API Version
4.3
See Also
ENVINITF, ENVINITF::GetTRENames, ENVINITF::GetTREValue, NITF Tagged Record Extensions Background