Fix classroom handling of sessions with no state yet

app/templates/courses/classroom-level-popover.jade

@@ -1,4 +1,4 @@
-- var completed = session && session.get('state').complete;
+- var completed = session && session.get('state') && session.get('state').complete;
 h3 #{i}. #{level.name.replace('Course: ', '')}
 if session
   p

app/templates/courses/classroom-view.jade

@@ -90,7 +90,7 @@ block content
                 - var session = sessionMap[levelID];
                 a(href=view.getLevelURL(level, course, courseInstance, session))
                   - var content = view.levelPopoverContent(level, session, i);
-                  if session && session.get('state').complete
+                  if session && session.get('state') && session.get('state').complete
                     .progress-bar.progress-bar-success(style=css, data-content=content, data-toggle='popover')= i
                   else if session
                     .progress-bar.progress-bar-warning(style=css, data-content=content, data-toggle='popover')= i

app/views/courses/ClassroomView.coffee

@@ -19,7 +19,7 @@ module.exports = class ClassroomView extends RootView
   id: 'classroom-view'
   template: template
   teacherMode: false
-  
+
   events:
     'click #edit-class-details-link': 'onClickEditClassDetailsLink'
     'click #activate-licenses-btn': 'onClickActivateLicensesButton'
@@ -57,7 +57,7 @@ module.exports = class ClassroomView extends RootView
       @listenToOnce sessions, 'sync', (sessions) ->
         @sessions.add(sessions.slice())
         sessions.courseInstance.sessionsByUser = sessions.groupBy('creator')
-    
+
     # generate course instance JIT, in the meantime have models w/out equivalents in the db
     for course in @courses.models
       query = {courseID: course.id, classroomID: @classroom.id}
@@ -83,7 +83,7 @@ module.exports = class ClassroomView extends RootView
       campaign = @campaigns.get(campaignID)
       courseInstance.sessions.campaign = campaign
     super()
-    
+
   afterRender: ->
     @$('[data-toggle="popover"]').popover({
       html: true
@@ -131,7 +131,7 @@ module.exports = class ClassroomView extends RootView
 
   classStats: ->
     stats = {}
-    
+
     playtime = 0
     total = 0
     for session in @sessions.models
@@ -140,8 +140,8 @@ module.exports = class ClassroomView extends RootView
       total += 1
     stats.averagePlaytime = if playtime and total then moment.duration(playtime / total, "seconds").humanize() else 0
     stats.totalPlaytime = if playtime then moment.duration(playtime, "seconds").humanize() else 0
-    
-    completeSessions = @sessions.filter (s) -> s.get('state').complete
+
+    completeSessions = @sessions.filter (s) -> s.get('state')?.complete
     stats.averageLevelsComplete = if @users.size() then (_.size(completeSessions) / @users.size()).toFixed(1) else 'N/A'
     stats.totalLevelsComplete = _.size(completeSessions)
     return stats
@@ -158,7 +158,7 @@ module.exports = class ClassroomView extends RootView
     onCourseInstanceCreated = =>
       courseInstance.addMember(userID)
       @listenToOnce courseInstance, 'sync', @render
-      
+
     if courseInstance.isNew()
       # adding the first student to this course, so generate the course instance for it
       courseInstance.save(null, {validate: false})
@@ -175,7 +175,7 @@ module.exports = class ClassroomView extends RootView
     })
     @openModalView(modal)
     modal.once 'remove-student', @onStudentRemoved, @
-    
+
   onStudentRemoved: (e) ->
     @users.remove(e.user)
     @render()
@@ -193,4 +193,4 @@ module.exports = class ClassroomView extends RootView
 
   getLevelURL: (level, course, courseInstance, session) ->
     return null unless @teacherMode and _.all(arguments)
-    "/play/level/#{level.slug}?course=#{course.id}&course-instance=#{courseInstance.id}&session=#{session.id}&observing=true"
+    "/play/level/#{level.slug}?course=#{course.id}&course-instance=#{courseInstance.id}&session=#{session.id}&observing=true"