Added average rating.

backend/postings/admin.py

@@ -10,3 +10,4 @@ admin.site.register(ReviewHelpfulVote)
 admin.site.register(University)
 admin.site.register(Professor)
 admin.site.register(Course)
+admin.site.register(User)

backend/postings/migrations/0002_auto_20181002_1338.py

@@ -0,0 +1,19 @@
+# Generated by Django 2.1.1 on 2018-10-02 13:38
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('postings', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='review',
+            name='author',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.PROTECT, to='postings.User'),
+        ),
+    ]

backend/postings/migrations/0003_auto_20181002_1355.py

@@ -0,0 +1,25 @@
+# Generated by Django 2.1.1 on 2018-10-02 13:55
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('postings', '0002_auto_20181002_1338'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='reviewhelpfulvote',
+            name='user',
+            field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to='postings.User'),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name='review',
+            name='author',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.PROTECT, to='postings.User'),
+        ),
+    ]

backend/postings/models.py

@@ -7,6 +7,10 @@ class User(models.Model):
 	# The user's birth date.
 	birth_date = models.DateField()
 
+	# Returns the name as the string representation of the user.
+	def __str__(self):
+		return self.name
+
 # Represents any object for which reviews can be made. (Universities, Professors, etc.)
 class RateableEntity(models.Model):
 	# Constants defined for types of rateable entities.
@@ -26,6 +30,18 @@ class RateableEntity(models.Model):
 	# The type of entity this is.
 	entity_type = models.SmallIntegerField(choices=TYPE_CHOICES)
 
+	# Gets the average of all the reviews.
+	def getAverageRating(self):
+		reviews = self.review_set.select_related()
+		rating_sum = 0
+		for review in reviews:
+			rating_sum += review.rating
+		return rating_sum / reviews.count()
+
+	# Simply returns the name as the string representation.
+	def __str__(self):
+		return self.name
+
 # A review represents any single data entry to the database.
 class Review(models.Model):
 	# An integer rating in the domain [1, 5]
@@ -41,7 +57,15 @@ class Review(models.Model):
 	# The date and time at which the last modification to this review was published.
 	last_updated_date = models.DateTimeField(auto_now=True)
 	# A reference to the person who created this review.
-	author = models.ForeignKey('postings.User', on_delete=models.PROTECT)
+	author = models.ForeignKey('postings.User', on_delete=models.PROTECT, null=True, blank=True)
+
+	# Gets the total number of votes which marked this review as 'helpful'.
+	def getHelpfulVoteCount(self):
+		ReviewHelpfulVote.objects.filter(pk=self.pk, helpful=True).count()
+
+	# Gets the total number of votes which marked this review as 'unhelpful'.
+	def getUnhelpfulVoteCount(self):
+		ReviewHelpfulVote.objects.filter(pk=self.pk, helpful=False).count()
 
 # A vote for a review as either positive or negative.
 class ReviewHelpfulVote(models.Model):
@@ -49,7 +73,8 @@ class ReviewHelpfulVote(models.Model):
 	review = models.ForeignKey('postings.Review', on_delete=models.CASCADE)
 	# Whether or not the referenced review was helpful.
 	helpful = models.BooleanField()
-	# TODO: Add a reference to the user who voted. The whole purpose of a separate vote object is to track who votes for what.
+	# The user who made this vote.
+	user = models.ForeignKey('postings.User', on_delete=models.CASCADE)
 
 # A RateableEntity for universities.
 class University(RateableEntity):

backend/postings/templates/postings/entity_pages/entity.html

@@ -4,7 +4,7 @@
 
 {% block content %}
 
-<h2>Name: {{ entity.name }}</h2>
+<h2>Name: {{ entity.name }}</h2> Average rating: {{ entity.average_rating }}
 
 {% block entity_info %}
 {% endblock %}

backend/postings/views.py

@@ -24,6 +24,7 @@ def universities(request):
 def university_entity(request, university_id):
 	try:
 		university = University.objects.get(pk=university_id)
+		university.average_rating = university.getAverageRating()
 	except University.DoesNotExist:
 		raise Http404("University does not exist")
 	return render(request, 'postings/entity_pages/university.html', {'entity': university})