enhanced subject line formatting options for email

Author: Alex-Jordan

conf/defaults.config

@@ -73,7 +73,7 @@ $mail{feedbackRecipients}    = [
 #   %% = literal percent sign
 #
 
-$mail{feedbackSubjectFormat} = "[WWfeedback] course:%c user:%u set:%s prob:%p sec:%x rec:%r";
+$mail{feedbackSubjectFormat} = '[WWfeedback] course:%c user:%u%s{ set:}%s%p{ prob:}%p%x{ sec:}%x%r{ rec:}%r';
 
 # feedbackVerbosity:
 #  0: send only the feedback comment and context link

lib/WeBWorK/ConfigValues.pm

@@ -829,13 +829,15 @@ sub getConfigValues ($ce) {
 			x('E-Mail'),
 			{
 				var  => 'mail{feedbackSubjectFormat}',
-				doc  => x('Format for the subject line in feedback emails'),
+				doc  => x('Format for the subject of feedback emails'),
 				doc2 => x(
-					'When students click the <em>Email Instructor</em> button to send feedback, WeBWorK fills in the '
-						. 'subject line. Here you can set the subject line. In it, you can have various bits of '
-						. 'information filled in with the following escape sequences.<p><ul><li>%c = course ID</li>'
+					'<p>When students click the <em>Email Instructor</em> button to send feedback, WeBWorK fills in '
+						. 'the subject line. Here you can set the subject line. In it, you can have various bits of '
+						. 'information filled in with the following escape sequences.</p><ul><li>%c = course ID</li>'
 						. '<li>%u = user ID</li><li>%s = set ID</li><li>%p = problem ID</li><li>%x = section</li>'
-						. '<li>%r = recitation</li><li>%% = literal percent sign</li></ul>'
+						. '<li>%r = recitation</li><li>%% = literal percent sign</li></ul><p>Sequences like '
+						. "'%r{ rec:}' will produce the string inside the braces if the corresponding key (%r in this "
+						. 'example) is defined and nonempty.'
 				),
 				width => 45,
 				type  => 'text'

lib/WeBWorK/ContentGenerator/Feedback.pm

@@ -109,16 +109,17 @@ sub initialize ($c) {
 		}
 
 		my %subject_map = (
-			'c' => $courseID,
-			'u' => $user    ? $user->user_id       : undef,
-			's' => $set     ? $set->set_id         : undef,
-			'p' => $problem ? $problem->problem_id : undef,
-			'x' => $user    ? $user->section       : undef,
-			'r' => $user    ? $user->recitation    : undef,
+			c   => $courseID,
+			u   => $user    ? $user->user_id       : undef,
+			s   => $set     ? $set->set_id         : undef,
+			p   => $problem ? $problem->problem_id : undef,
+			x   => $user && $user->section    ? $user->section    : undef,
+			r   => $user && $user->recitation ? $user->recitation : undef,
 			'%' => '%',
 		);
 		my $chars   = join('', keys %subject_map);
 		my $subject = $ce->{mail}{feedbackSubjectFormat} || 'WeBWorK question from %c: %u set %s/prob %p';
+		$subject =~ s/%([$chars])\{(.*?)\}/defined $subject_map{$1} ? $2 : ''/eg;
 		$subject =~ s/%([$chars])/defined $subject_map{$1} ? $subject_map{$1} : ''/eg;
 
 		my %data = (

lib/WeBWorK/Utils/ProblemProcessing.pm

@@ -384,18 +384,19 @@ sub jitar_send_warning_email ($c, $userProblem) {
 	$problemID = join('.', jitar_id_to_seq($problemID));
 
 	my %subject_map = (
-		'c' => $courseID,
-		'u' => $userID,
-		's' => $setID,
-		'p' => $problemID,
-		'x' => $user->section,
-		'r' => $user->recitation,
+		c   => $courseID,
+		u   => $userID,
+		s   => $setID,
+		p   => $problemID,
+		x   => $user->section    ? $user->section    : undef,
+		r   => $user->recitation ? $user->recitation : undef,
 		'%' => '%',
 	);
 	my $chars   = join('', keys %subject_map);
 	my $subject = $ce->{mail}{feedbackSubjectFormat}
 		|| 'WeBWorK question from %c: %u set %s/prob %p';    # default if not entered
-	$subject =~ s/%([$chars])/defined $subject_map{$1} ? $subject_map{$1} : ""/eg;
+	$subject =~ s/%([$chars])\{(.*?)\}/defined $subject_map{$1} ? $2 : ''/eg;
+	$subject =~ s/%([$chars])/defined $subject_map{$1} ? $subject_map{$1} : ''/eg;
 
 	my $full_name     = $user->full_name;
 	my $email_address = $user->email_address;