From decd39123b303b8c05f13c55f4230849fbb174f3 Mon Sep 17 00:00:00 2001
From: Derek Steinmoeller <Derek.Steinmoeller@D2L.com>
Date: Thu, 5 Oct 2017 14:34:07 -0400
Subject: [PATCH 1/2] Allow student_id to be retrieved from a (configurable)
 LTI parameter. Default is custom_student_id, otherwise can be set in
 authen_LTI.conf.

---
 conf/authen_LTI.conf.dist         | 12 ++++++++++++
 lib/WeBWorK/Authen/LTIAdvanced.pm | 13 ++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/conf/authen_LTI.conf.dist b/conf/authen_LTI.conf.dist
index 17950b38d2..e34aee51b0 100644
--- a/conf/authen_LTI.conf.dist
+++ b/conf/authen_LTI.conf.dist
@@ -85,6 +85,18 @@ $preferred_source_of_username = "lis_person_contact_email_primary";
 
 #$strip_address_from_email = 1;
 
+################################################################################
+# LTI Preferred source of Student Id
+################################################################################
+
+# If preferred_source_of_student_id is not set, WeBWorK will look in the LTI
+# parameter 'custom_student_id.' If preferred_source_of_student_id is set, then
+# WeBWorK will look in the LTI parameter specified below. This parameter may be
+# dependendent on the LMS. E.G., In D2L, student_id is stored in OrgDefinedId and
+# the corresponding LTI parameter is called ext_d2l_orgdefinedid.
+
+#$preferred_source_of_student_id = "ext_d2l_orgdefinedid";
+
 ################################################################################
 # LTI Basic Authentication Parameters 
 ################################################################################
diff --git a/lib/WeBWorK/Authen/LTIAdvanced.pm b/lib/WeBWorK/Authen/LTIAdvanced.pm
index 1af174dafd..c889e58f37 100644
--- a/lib/WeBWorK/Authen/LTIAdvanced.pm
+++ b/lib/WeBWorK/Authen/LTIAdvanced.pm
@@ -167,6 +167,7 @@ sub get_credentials {
 	 ['oauth_timestamp', 'oauth_timestamp'],
 	 ['section', 'custom_section'],
 	 ['recitation', 'custom_recitation'],
+	 ['student_id', 'custom_student_id'],
 	);
 
       # Some LMS's misspell the lis_person_sourcedid parameter name
@@ -199,6 +200,12 @@ sub get_credentials {
 	$self->{user_id} =~ s/@.*$// if
 	  $ce->{strip_address_from_email};
       }
+
+     if (!defined($self->{student_id})
+         and defined($ce->{preferred_source_of_student_id})) {
+       my $user_id_lti_param_name = $ce->{preferred_source_of_student_id};
+       $self->{student_id} = $r->param($user_id_lti_param_name);
+     }
       
       # For setting up its helpful to print out what the system think the
       # User id and address is at this point 
@@ -206,7 +213,9 @@ sub get_credentials {
 	warn "=========== summary ============";
 	warn "User id is |$self->{user_id}|\n";
 	warn "User mail address is |$self->{email}|\n";
+	warn "Student id is |$self->{student_id}|\n";
 	warn "preferred_source_of_username is |", $ce->{preferred_source_of_username}//'undefined',"|\n";
+	warn "preferred_source_of_student_id is |", $ce->{preferred_source_of_student_id}//'undefined',"|\n";
 	warn "================================\n";
       }
       if (!defined($self->{user_id})) {
@@ -518,6 +527,7 @@ sub create_user {
   $newUser-> section($self->{section} // "");
   $newUser->recitation($self->{recitation} // "");
   $newUser->comment(formatDateTime(time, "local"));
+  $newUser->student_id($self->{student_id} // "");
 
   # Allow sites to customize the user
   if (defined($ce->{LTI_modify_user})) {
@@ -593,6 +603,7 @@ sub maybe_update_user {
     $tempUser->status("C");
     $tempUser-> section($self->{section} // "");
     $tempUser->recitation($self->{recitation} // "");
+    $tempUser->student_id($self->{student_id} // "");
     
     # Allow sites to customize the temp user
     if (defined($ce->{LTI_modify_user})) {
@@ -601,7 +612,7 @@ sub maybe_update_user {
 
     my @elements = qw(last_name first_name 
 		      email_address status 
-		      section recitation);
+		      section recitation student_id);
 
     my $change_made = 0;
 

From 99815e1bd664c20adcacf2fc030e080af0593e44 Mon Sep 17 00:00:00 2001
From: Derek Steinmoeller <Derek.Steinmoeller@D2L.com>
Date: Fri, 13 Oct 2017 13:19:00 -0400
Subject: [PATCH 2/2] Warning message handles case when student_id is
 undefined.

---
 lib/WeBWorK/Authen/LTIAdvanced.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/WeBWorK/Authen/LTIAdvanced.pm b/lib/WeBWorK/Authen/LTIAdvanced.pm
index c889e58f37..61a4a3c00f 100644
--- a/lib/WeBWorK/Authen/LTIAdvanced.pm
+++ b/lib/WeBWorK/Authen/LTIAdvanced.pm
@@ -213,7 +213,7 @@ sub get_credentials {
 	warn "=========== summary ============";
 	warn "User id is |$self->{user_id}|\n";
 	warn "User mail address is |$self->{email}|\n";
-	warn "Student id is |$self->{student_id}|\n";
+	warn "Student id is |", $self->{student_id}//'undefined',"|\n";
 	warn "preferred_source_of_username is |", $ce->{preferred_source_of_username}//'undefined',"|\n";
 	warn "preferred_source_of_student_id is |", $ce->{preferred_source_of_student_id}//'undefined',"|\n";
 	warn "================================\n";