NAME

       Business::EDI - Top level class for generating U.N. EDI interchange objects and
       subobjects.

SYNOPSIS

         use Business::EDI;

         my $edi = Business::EDI-new('d09b');      # set the EDI spec version
         my $rtc = $edi->codelist('ResponseTypeCode', $json) or die "Unrecognized code!";
         printf "EDI response type: %s - %s (%s)\n", $rtc->code, $rtc->label, $rtc->value;

         my $msg = Business::EDI::Message->new($ordrsp) or die "Failed Message constructor";
         foreach ($msg->xpath('line_detail/all_LIN') {
             ($_->part(7143) || '') eq 'EN' or next;
             print $_->part(7140)->value, "\n";    # print all the 13-digit (EN) ISBNs
         }

DESCRIPTION

       The focus of functionality is to provide object based access to EDI messages and
       subelements.  At present, the EDI input processed by Business::EDI objects is JSON from
       the edi4r ruby library, and there is no EDI output beyond the perl objects themselves.

NAMESPACE

       When you "use Business::EDI;" the following package namespaces are also loaded:
           Business::EDI::Segment_group
           Business::EDI::Message

       That's why the example message constructor in SYNOPSIS would succeed without having done
       "use Business::EDI::Message;"

EDI Structure

       Everything depends on the spec.  That means you have to have declared a spec version
       before you can create or parse a given chunk of data.  The exception is a whole EDI
       message, because each message declares its spec version internally.

       EDI has a hierachical specification defining data.  From top to bottom, it includes:

       Communication - containing one or more messages (not yet modeled here)
       Message       - containing segment groups and segments
       Segment Group - containing segments
       Segment       - containing composites, codelists and data elements
       Composite     - containing multiple codelists and/or data elements
       Codelist      - enumerated value from a spec-defined set
       Data Element  - unenumerated value

       This module handles messages and everything below, but not (yet) communications.

CLASS FUNCTIONS

       Much more documentation needed here...

   new()
       Constructor

OBJECT METHODS (General)

   value()
       Get/set accessor for the value of the field.

   code()
       The string code designating this node's type.  The code is what is what the spec uses to
       refer to the object's definition.  For example, a composite "C504", segment "RFF", data
       element "7140", etc.

       Don't be confused when dealing with CodeList objects.  Calling code() gets you the
       4-character code of the CodeList field, NOT what that CodeList is currently set to.  For
       that use value().

   desc()
       English description of the element.

METHODS (for Traversal)

   part_keys()
       This method returns strings that can be fed to part() like:
           foreach ($x->part_keys) { something($x->part($_)) }

       This is similar to doing:
           foreach (keys %x) { something($x{$_}) }

       In this way an object can be exhaustively, recursively parsed without further knowledge of
       it.

   part($key)
       Returns subelement(s) of the object.  The key can reference any subobject allowed by the
       spec.  If the subobject is repeatable, then prepending "all_" to the key will return an
       array of all such subobjects.  This is the safest and most comprehensive approach.  Using
       part($key) without "all_" to retrieve when there is only one $key subobject will succeed.
       Using part($key) without "all_" to retrieve when there are multiple $key subobjects will
       FAIL.  Since that difference is only dependent on data, you should always use "all_" when
       dealing with a repeatable field (or xpath, see below).

       Examples:

           my $qty  = $detail->part('QTY');      # FAILURE PRONE!
           my @qtys = $detail->part('all_QTY');  # OK!

   xpath($path)
       $path can traverse multiple depths in representation via one call.  For example:

           $message->xpath('all_SG26/all_QTY/6063')

       is like this function foo():

           sub foo {
               my @x;
               for my $sg ($message->part->('all_SG26') {
                   for ($sg->part('all_QTY') {
                       push @x, $->part('6063');
                   }
               }
               return @x;
           }

       The xpath version is much nicer!  However this is nowhere near as fully featured as W3C
       xpath for XML.  This is more like a multple-depth part().

       Examples:
           my @obj_1154 = $message->xpath('line_detail/SG31/RFF/C506/1154');

   xpath_value($path)
       Returns value(s) instead of object(s).

       Examples:
           'ORDRSP' eq $ordrsp->xpath_value('UNH/S009/0065') or die "Wrong Message Type!";

WARNINGS

       This code is experimental.  EDI is a big spec with many revisions.

       At the lower levels, all data elements, codelists, composites and segments from the most
       recent spec (D09B) are present.

SEE ALSO

        Business::EDI::Spec
        edi4r - http://edi4r.rubyforge.org

AUTHOR

       Joe Atzberger