Add role to ExternalUser and update it via LTI

app/controllers/concerns/lti.rb

@@ -52,6 +52,21 @@ module Lti
   end
   private :external_user_name
 
+  def external_user_role(provider)
+    result = 'learner'
+    provider.roles.each do |role|
+      case role.downcase!
+      when 'administrator'
+        result = 'admin'
+      when 'instructor'
+        result = 'teacher' if result == 'learner'
+      else # 'learner'
+        next
+      end
+    end
+    result
+  end
+
   def refuse_lti_launch(options = {})
     return_to_consumer(lti_errorlog: options[:message], lti_errormsg: t('sessions.oauth.failure'))
   end
@@ -129,7 +144,7 @@ module Lti
 
   def set_current_user
     @current_user = ExternalUser.find_or_create_by(consumer_id: @consumer.id, external_id: @provider.user_id)
-    @current_user.update(email: external_user_email(@provider), name: external_user_name(@provider))
+    @current_user.update(email: external_user_email(@provider), name: external_user_name(@provider), role: external_user_role(@provider))
   end
   private :set_current_user
 

app/views/external_users/show.html.slim

@@ -3,6 +3,7 @@ h1 = @user.name
 = row(label: 'external_user.name', value: @user.name)
 //= row(label: 'external_user.email', value: @user.email)
 = row(label: 'external_user.consumer', value: link_to(@user.consumer, @user.consumer))
+= row(label: 'external_user.role', value: t("users.roles.#{@user.role}"))
 
 h4.mt-4 = link_to(t('.exercise_statistics'), statistics_external_user_path(@user))
 

db/migrate/20181116143743_add_role_to_external_users.rb

@@ -0,0 +1,5 @@
+class AddRoleToExternalUsers < ActiveRecord::Migration[5.2]
+  def change
+    add_column :external_users, :role, :string, default: 'learner', null: false
+  end
+end