--- loncom/enrollment/localenroll.pm	2021/03/31 02:19:58	1.60
+++ loncom/enrollment/localenroll.pm	2021/06/15 20:52:27	1.61
@@ -1,6 +1,6 @@
 # functions to glue school database system into Lon-CAPA for 
 # automated enrollment
-# $Id: localenroll.pm,v 1.60 2021/03/31 02:19:58 raeburn Exp $
+# $Id: localenroll.pm,v 1.61 2021/06/15 20:52:27 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -655,6 +655,101 @@ sub check_instclasses {
     return 'ok';
 }
 
+=pod
+
+=item instsec_reformat()
+
+ Inputs: $dom, $action, $instsecref
+
+ $dom is the course's domain
+ $action is either: clutter or declutter
+ $instsecref is a reference to a hash, in which each key is
+ course num:course code, and each value is either an array of 
+ institutional sections, or (in the case of crosslisted courses)
+ an array of institutional course sections.
+
+ Returns: ok
+
+ Side effects: will modify the items in the array as determined by
+ code implemented for the domain.  Modification will differ depending
+ on whether the action is clutter or declutter.
+
+ The idea is that "clutter" will modify the name of the section such
+ that a concatenation of institutional code then (modified) section
+ will result in a string that other customized routines in localenroll.pm
+ can separate without ambiguity into instituional code then (real)
+ institutional section using a regular expression.
+
+ Conversely, "declutter" will modify the name of an already modified
+ item such that display of the concatenated string (e.g., for a 
+ crosslisting in the course catalog) does not include the "added"
+ characters used to eliminate ambiguity. 
+
+ Examples (MSU):
+
+ Starting in Fall 2021 at MSU, institution section numbers are no
+ longer guaranteed to be three digit numbers (including leading zeroes).
+
+ So, for example the course code: fs21phy183b might have sections:
+ 001, 002, LEC1, LEC2, and be crosslisted with fs21phy233b (with 
+ sections: 730, LEC3, LEC4).
+
+ The sections: LEC1, and LEC2 should be changed to _LEC1, and _LEC2
+ before creating the inner keys in the %affiliates hash of a hash,
+ passed to fetch_enrollment() in Enrollment.pm.  They will however
+ be stored in the course's environment as LEC1 and LEC2.
+
+ For the crosslistings, LEC3 and LEC4 should be changed to 
+ _LEC3 and _LEC4 before storing in the course's environment.db file.
+
+ In both cases when it comes time to extract the various components
+ of an institutional section code (i.e., the concatenated string) in
+ fetch_enrollment(), for example, the regexp used at MSU would be:
+ 
+ if ($class =~ m/^([suf]s)(\d{2})(\w{2,4})(\d{3,4}[A-Za-z]?)(\d{3}|_[A-Za-z0-9]{1,5})$/) {
+     my ($sem,$yr,$subj,$crse,$sec) = ($1,$2,$3,$4,$5);
+
+ The three digit sections would match the \d{3} and the other sections
+ (LEC1, LEC2 etc.) would match the _[A-Za-z0-9]{1,5}.
+
+ The customization in &instsec_reformat() would be:
+
+     if ($action eq 'clutter') {
+         unless ($item =~ /^\d{3}$/) {
+             $item = '_'.$item;
+         }
+     } elsif ($action eq 'declutter') {
+         if ($item =~ /^([suf]s\d{2}\w{2,4}\d{3,4}[A-Za-z]?)(\d{3}|_[A-Za-z0-9]{1,5})$/) {
+             my ($instcode,$instsec) = ($1,$2);
+             $instsec =~ s/^_//;
+             $item = $instcode.$instsec;
+         } elsif ($item =~ /^_[A-Za-z0-9]{1,5}$/) {
+             $item =~ s/^_//;
+         }
+     }
+
+=cut
+
+sub instsec_reformat {
+    my ($dom,$action,$instsecref) = @;
+    if ((ref($instsecref) eq 'HASH') &&
+        (($action eq 'clutter') || ($action eq 'declutter'))) {
+        foreach my $key (keys(%{$instsecref})) {
+            if (ref($instsecref->{$key}) eq 'ARRAY') {
+                foreach my $sec (@{$instsecref->{$key}}) {
+                    if ($action eq 'clutter') {
+                        # modify the section, as needed.
+                        next;
+                    } elsif ($action eq 'declutter') {
+                        # modify the section, as needed.
+                        next;
+                    }
+                }
+            }
+        }
+    }
+    return 'ok';
+}
 
 =pod