api_create_blog_view.py

from blog.api.serializers import BlogPostCreateSerializer

CREATE_SUCCESS = 'created'

# Response: https://gist.github.com/mitchtabian/78d7dcbeab4135c055ff6422238a31f9
# Url: https://<your-domain>/api/blog/create
# Headers: Authorization: Token <token>
@api_view(['POST'])
@permission_classes((IsAuthenticated,))
def api_create_blog_view(request):

	if request.method == 'POST':

		data = request.data
		data['author'] = request.user.pk
		serializer = BlogPostCreateSerializer(data=data)

		data = {}
		if serializer.is_valid():
			blog_post = serializer.save()
			data['response'] = CREATE_SUCCESS
			data['pk'] = blog_post.pk
			data['title'] = blog_post.title
			data['body'] = blog_post.body
			data['slug'] = blog_post.slug
			data['date_updated'] = blog_post.date_updated
			image_url = str(request.build_absolute_uri(blog_post.image.url))
			if "?" in image_url:
				image_url = image_url[:image_url.rfind("?")]
			data['image'] = image_url
			data['username'] = blog_post.author.username
			return Response(data=data)
		return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

BlogPostCreateSerializer.py

class BlogPostCreateSerializer(serializers.ModelSerializer):


	class Meta:
		model = BlogPost
		fields = ['title', 'body', 'image', 'date_updated', 'author']


	def save(self):
		
		try:
			image = self.validated_data['image']
			title = self.validated_data['title']
			if len(title) < MIN_TITLE_LENGTH:
				raise serializers.ValidationError({"response": "Enter a title longer than " + str(MIN_TITLE_LENGTH) + " characters."})
			
			body = self.validated_data['body']
			if len(body) < MIN_BODY_LENGTH:
				raise serializers.ValidationError({"response": "Enter a body longer than " + str(MIN_BODY_LENGTH) + " characters."})
			
			blog_post = BlogPost(
								author=self.validated_data['author'],
								title=title,
								body=body,
								image=image,
								)

			url = os.path.join(settings.TEMP , str(image))
			storage = FileSystemStorage(location=url)

			with storage.open('', 'wb+') as destination:
				for chunk in image.chunks():
					destination.write(chunk)
				destination.close()

			if sys.getsizeof(image.file) > IMAGE_SIZE_MAX_BYTES:
				os.remove(url)
				raise serializers.ValidationError({"response": "That image is too large. Images must be less than 3 MB. Try a different image."})

			img = cv2.imread(url)
			dimensions = img.shape # gives: (height, width, ?)
			
			aspect_ratio = dimensions[1] / dimensions[0] # divide w / h
			if aspect_ratio < 1:
				os.remove(url)
				raise serializers.ValidationError({"response": "Image height must not exceed image width. Try a different image."})

			os.remove(url)
			blog_post.save()
			return blog_post
		except KeyError:
			raise serializers.ValidationError({"response": "You must have a title, some content, and an image."})