I am building an API for a game and need to select a random game round for a randomly chosen resource.
Choosing the random resource works. What I am trying to do now, in order to coordinate players is to filter the game rounds by the resource that has been chosen randomly and then return a random game round.
The code below shows what I have tried so far, namely to access the resource for which a game round has been played over the method with the @property decorator.
models.py
class Resource(models.Model):
id = models.PositiveIntegerField(null=False, primary_key=True)
hash_id = models.CharField(max_length=256)
creators = models.ManyToManyField(Creator)
titles = models.ManyToManyField(Title)
created_start = models.DateField(null=True)
created_end = models.DateField(null=True)
location = models.CharField(max_length=512, null=True)
institution_source = models.CharField(max_length=512, blank=True)
institution = models.CharField(max_length=512, blank=True)
origin = models.URLField(max_length=256, null=True)
enabled = models.BooleanField(default=True)
media_type = models.CharField(max_length=256, default='picture')
objects = models.Manager()
def __str__(self):
return self.hash_id or ''
@property
def tags(self):
tags = self.taggings.values('tag').annotate(count=Count('tag'))
return tags.values('tag_id', 'tag__name', 'tag__language', 'count')
class Gameround(models.Model):
user = models.ForeignKey(CustomUser, on_delete=models.SET_NULL, null=True)
gamesession = models.ForeignKey(Gamesession, on_delete=models.CASCADE)
created = models.DateTimeField(editable=False)
score = models.PositiveIntegerField(default=0)
objects = models.Manager()
def save(self, *args, **kwargs):
if not self.id:
self.created = timezone.now()
return super().save(*args, **kwargs)
def create(self):
pass
@property
def tags(self):
tags = self.taggings.values('tag')
return tags.values('tag_id', 'tag__name', 'tag__language', 'resource_id')
class Tagging(models.Model):
user = models.ForeignKey(CustomUser, on_delete=models.SET_NULL, null=True)
gameround = models.ForeignKey(Gameround, on_delete=models.CASCADE, related_name='taggings')
resource = models.ForeignKey(Resource, on_delete=models.CASCADE, related_name='taggings')
tag = models.ForeignKey(Tag, on_delete=models.CASCADE)
created = models.DateTimeField(editable=False)
score = models.PositiveIntegerField(default=0)
origin = models.URLField(max_length=256, blank=True, default='')
objects = models.Manager()
def create(self, tag):
tagging = self.create(tag=tag)
def __str__(self):
return str(self.tag) or ''
def save(self, *args, **kwargs):
if not self.id:
self.created = timezone.now()
return super().save(*args, **kwargs)
I am then serialising the game round like this:
*serializers.py
class GameroundSerializer(serializers.ModelSerializer):
gamesession = GamesessionSerializer(read_only=True)
user = CustomUserSerializer(read_only=True)
tags_to_compare = serializers.SerializerMethodField('get_tags_to_compare')
class Meta:
model = Gameround
fields = ['id', 'user', 'gamesession', 'created', 'score', 'tags_to_compare']
def get_tags_to_compare(self, round):
taggings = round.tags
return taggings
def to_representation(self, data):
data = super().to_representation(data)
return data
In the view I have a get request which first chooses a random resource, then I am trying to filter the game rounds to only include the ones where this resource was involved and then I am trying to retrieve a random game round.
views.py
class GameroundView(APIView):
"""
API endpoint for game rounds
"""
def get(self, request, *args, **kwargs):
controller = GameViewController()
random_resource = controller.get_resource()
gameround = Gameround.objects.all().filter(taggings__resource_id=random_resource).order_by("?").first()
gameround_serializer = GameroundSerializer(gameround)
return Response(gameround_serializer.data)
This does not seem to be working since I keep getting the error "The response content must be rendered before it can be iterated over."
I have also tried creating an id variable and passing it on as the resource_id like this:
# id of the random Resource for the game round
random_resource_id = random_resource.get(random_resource.id)
gameround = Gameround.objects.all().filter(taggings__resource_id=random_resource_id).order_by("?").first()
This leads to the 'Response' object has no attribute 'id' error when I reload the page in the browser.
Does anyone know how I can solve this issue?
Thank you in advance!
Below also the Gameviewcontroller that is inside the views.py file
class GameViewController:
def get_random_object(self, MyModel):
random_object = None
object_count = MyModel.objects.all().count() 1
while not MyModel.objects.all().filter(id=random_object).exists():
for obj in range(object_count):
n = random.randint(1, object_count)
if MyModel.objects.all().filter(id=n).exists():
random_object = n
return random_object
def get_random_id(self, MyModel):
"""Method for large querysets"""
random_object = None
object_count = MyModel.objects.all().count() 1
for obj in range(object_count):
n = random.randint(1, object_count)
while not MyModel.objects.all().filter(id=n).exists():
alt = random.randint(1, object_count)
if MyModel.objects.all().filter(id=alt).exists():
random_object = n
return random_object
def get_resource(self):
random_resource_id = self.get_random_object(Resource)
current_resource = Resource.objects.all().filter(id=random_resource_id)
resource_serializer = ResourceSerializer(current_resource, many=True)
data = {'resource': resource_serializer.data}
return Response(data, status=status.HTTP_200_OK)
def get_gameround_matching_resource(self, random_resource):
"""Checks if a previously played game round exists for a randomly chosen resource"""
current_gameround = Gameround.objects.all().filter(ressource__in=random_resource).order_by('?').first()
if current_gameround.exists():
gameround_serializer = GameroundSerializer(current_gameround)
data = {'gameround': gameround_serializer.data}
return Response(data, status=status.HTTP_200_OK)
def timer(self, start):
"""Start a new timer as soon as a gameround has been selected"""
start_time = start
elapsed_time = None
if start_time is not None:
start_time = time.perf_counter()
"""Stop the timer, and return the elapsed time"""
if start_time is None:
elapsed_time = time.perf_counter() - start_time
return elapsed_time
def get_gamesession(self):
"""Retrieves a randomly chosen gamesession object"""
current_gamesession = Gamesession.objects.all().order_by('?').first()
gamesession_serializer = GamesessionSerializer(current_gamesession)
data = {'gameround': gamesession_serializer.data}
return Response(data, status=status.HTTP_200_OK)
CodePudding user response：
I finally managed to solve it by rewriting the get request like this:
def get(self, request, *args, **kwargs):
random_resource = Resource.objects.all().order_by('?').first()
resource_serializer = ResourceSerializer(random_resource) # Response is a serialized JSON object
random_resource_id = random_resource.id # id of the random Resource for the game round
gameround = Gameround.objects.all().filter(taggings__resource_id=random_resource_id).order_by("?").first()
gameround_serializer = GameroundSerializer(gameround)
return Response({
'resource to coordinate': resource_serializer.data,
'gameround': gameround_serializer.data,
})