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