Remove clear_lti_session_data as it is no longer needed

* no lti session data anymore included in the function
* decided not to delete the pg_id here as it is handled in create_through_lti and implement
* the function is only called once without an exercise id so the values are now directly deleted there

app/controllers/concerns/lti.rb

@@ -19,24 +19,6 @@ module Lti
 
   private :build_tool_provider
 
-  # exercise_id.nil? ==> the user has logged out. All session data is to be destroyed
-  # exercise_id.exists? ==> the user has submitted the results of an exercise to the consumer.
-  # Only the assignment of the programming group is deleted.
-  def clear_lti_session_data(exercise_id = nil)
-    if exercise_id.nil?
-      session.delete(:external_user_id)
-      session.delete(:study_group_id)
-      session.delete(:embed_options)
-    end
-    session.delete(:pg_id)
-
-    # We allow reusing the LTI credentials and don't remove them on purpose.
-    # This allows users to jump between remote and web evaluation with the same behavior.
-    # Also it prevents the user from deleting the lti_parameters for their programming team members.
-  end
-
-  private :clear_lti_session_data
-
   def consumer_return_url(provider, options = {})
     consumer_return_url = provider.try(:launch_presentation_return_url) || params[:launch_presentation_return_url]
     consumer_return_url += "?#{options.to_query}" if consumer_return_url && options.present?

app/controllers/concerns/redirect_behavior.rb

@@ -16,7 +16,6 @@ module RedirectBehavior
       # redirect 10 percent pseudorandomly to the feedback page
       if current_user.respond_to? :external_id
         if @submission.redirect_to_feedback? && !@embed_options[:disable_redirect_to_feedback]
-          clear_lti_session_data(@submission.exercise_id)
           redirect_to_user_feedback
           return
         end
@@ -27,7 +26,6 @@ module RedirectBehavior
           flash[:notice] = I18n.t('exercises.submit.full_score_redirect_to_own_rfc')
           flash.keep(:notice)
 
-          clear_lti_session_data(@submission.exercise_id)
           respond_to do |format|
             format.html { redirect_to(rfc) }
             format.json { render(json: {redirect: url_for(rfc)}) }
@@ -45,7 +43,6 @@ module RedirectBehavior
           # increase counter 'times_featured' in rfc
           rfc.increment(:times_featured)
 
-          clear_lti_session_data(@submission.exercise_id)
           respond_to do |format|
             format.html { redirect_to(rfc) }
             format.json { render(json: {redirect: url_for(rfc)}) }
@@ -56,7 +53,6 @@ module RedirectBehavior
     else
       # redirect to feedback page if score is less than 100 percent
       if @exercise.needs_more_feedback?(@submission) && !@embed_options[:disable_redirect_to_feedback]
-        clear_lti_session_data(@submission.exercise_id)
         redirect_to_user_feedback
       else
         redirect_to_lti_return_path
@@ -128,7 +124,6 @@ module RedirectBehavior
     )
 
     path = lti_return_path(submission_id: @submission.id)
-    clear_lti_session_data(@submission.exercise_id)
     respond_to do |format|
       format.html { redirect_to(path) }
       format.json { render(json: {redirect: path}) }

app/controllers/sessions_controller.rb

@@ -47,13 +47,14 @@ class SessionsController < ApplicationController
     authorize(@submission, :show?)
     lti_parameter = current_user.lti_parameters.find_by(exercise: @submission.exercise, study_group_id: current_user.current_study_group_id)
     @url = consumer_return_url(build_tool_provider(consumer: current_user.consumer, parameters: lti_parameter&.lti_parameters))
-
-    clear_lti_session_data(@submission.exercise_id)
   end
 
   def destroy
     if current_user&.external_user?
-      clear_lti_session_data
+      session.delete(:external_user_id)
+      session.delete(:study_group_id)
+      session.delete(:embed_options)
+      session.delete(:pg_id)
 
       # In case we have another session as an internal user, we set the study group for this one
       internal_user = find_or_login_current_user