Merge pull request #1464 from taniwallach/lti-submit-bug-fix

Hotfix: LTI grade passback

lib/WeBWorK/Authen/LTIAdvanced.pm

@@ -36,8 +36,6 @@ use URI::Escape;
 use Net::OAuth;
 use constant MP2 => ( exists $ENV{MOD_PERL_API_VERSION} and $ENV{MOD_PERL_API_VERSION} >= 2 );
 
-use constant TIME_DIFF_THRESHOLD => 5; # seconds, threshold to report different between system time and oauth_timestamp time
-
 $Net::OAuth::PROTOCOL_VERSION = Net::OAuth::PROTOCOL_VERSION_1_0A;
 
 BEGIN {
@@ -149,8 +147,7 @@ sub get_credentials {
   my $curr_time = time();
   my $delta_time = $curr_time - $oauth_time;
   my $delta_min = (0.0 + $delta_time) / (60.0);
-  if ( $ce->{debug_lti_parameters} ||
-	 ( abs($delta_time) > TIME_DIFF_THRESHOLD ) ) {
+  if ( $ce->{debug_lti_parameters} ) {
     warn join("\n",
 	"============================",
 	"===== timestamp info =======",

lib/WeBWorK/Authen/LTIAdvanced/SubmitGrade.pm

@@ -250,7 +250,9 @@ sub submit_grade {
   # which should be dependent on the student + the assignment if a
   # "homework" level sourcedid. This part can be used twice
   my $uuid_p1 = create_uuid_as_string(UUID_SHA1, UUID_NS_URL, $sourcedid);
-  my $uuid_p2;
+
+  # Second part is a time dependent portion
+  my $uuid_p2 = create_uuid_as_string(UUID_TIME);
 
   my $lti_check_prior = $ce->{lti_check_prior} // 0; # Should we first poll the LMS for the current grade
 
@@ -296,14 +298,10 @@ EOS
     warn("Retrieving prior grade using sourcedid: $sourcedid") if
       $ce->{debug_lti_parameters};
 
-
     $requestGen = Net::OAuth->request("consumer");
 
     $requestGen->add_required_message_params('body_hash');
 
-    # Generate a better nonce, second part is a time dependent portion
-    $uuid_p2 = create_uuid_as_string(UUID_TIME);
-
     $gradeRequest = $requestGen->new(
 		  request_url => $request_url,
 		  request_method => "POST",