+=head2 SendCirculationAlert
+
+Send out a C<check-in> or C<checkout> alert using the messaging system.
+
+B<Parameters>:
+
+=over 4
+
+=item type
+
+Valid values for this parameter are: C<CHECKIN> and C<CHECKOUT>.
+
+=item item
+
+Hashref of information about the item being checked in or out.
+
+=item borrower
+
+Hashref of information about the borrower of the item.
+
+=item branch
+
+The branchcode from where the checkout or check-in took place.
+
+=back
+
+B<Example>:
+
+ SendCirculationAlert({
+ type => 'CHECKOUT',
+ item => $item,
+ borrower => $borrower,
+ branch => $branch,
+ });
+
+=cut
+
+sub SendCirculationAlert {
+ my ($opts) = @_;
+ my ($type, $item, $borrower, $branch) =
+ ($opts->{type}, $opts->{item}, $opts->{borrower}, $opts->{branch});
+ my %message_name = (
+ CHECKIN => 'Item Check-in',
+ CHECKOUT => 'Item Checkout',
+ );
+ my $borrower_preferences = C4::Members::Messaging::GetMessagingPreferences({
+ borrowernumber => $borrower->{borrowernumber},
+ message_name => $message_name{$type},
+ });
+ my $letter = C4::Letters::getletter('circulation', $type);
+ C4::Letters::parseletter($letter, 'biblio', $item->{biblionumber});
+ C4::Letters::parseletter($letter, 'biblioitems', $item->{biblionumber});
+ C4::Letters::parseletter($letter, 'borrowers', $borrower->{borrowernumber});
+ C4::Letters::parseletter($letter, 'branches', $branch);
+ my @transports = @{ $borrower_preferences->{transports} };
+ # warn "no transports" unless @transports;
+ for (@transports) {
+ # warn "transport: $_";
+ my $message = C4::Message->find_last_message($borrower, $type, $_);
+ if (!$message) {
+ #warn "create new message";
+ C4::Message->enqueue($letter, $borrower, $_);
+ } else {
+ #warn "append to old message";
+ $message->append($letter);
+ $message->update;
+ }
+ }
+ $letter;
+}
+