Django REST error when serializing uploaded image - django-rest-framework

Question

I'm getting a serializer error:
"Upload a valid image. The file you uploaded was either not an image
or a corrupted image"
When trying to serialize an uploaded image
My code:
Models:
class Post(models.Model):
text = models.TextField(max_length=10000)
class Image(models.Model):
post = models.ForeignKey(Post, on_delete=models.CASCADE)
image = models.ImageField(blank=False, null=False, upload_to='test')
View:
class CreateNewPostAPIView(generics.CreateAPIView):
serializer_class = serializers.NewPostSerializer
def get_serializer_context(self):
context = super().get_serializer_context()
if self.request.data.get('image', None):
context['image'] = self.request.data.pop('image', None)
return context
Serializers:
class NewPostSerializer(serializers.ModelSerializer):
def create(self, validated_data):
post = Post.objects.create(**validated_data)
image = self.context['image'][0] # working with only one image for now
# image is of type <class'django.core.files.uploadedfile.InMemoryUploadedFile'>
serializer = ImageSerializer(data={'post': post.pk, 'image': image})
is_valid = serializer.is_valid() # it's always False!
return post
class ImageSerializer(serializers.ModelSerializer):
class Meta:
model = Image
fields = ('post', 'image')
I already tried doing that without a serializer and it's working with this code:
class NewPostSerializer(serializers.ModelSerializer):
def create(self, validated_data):
post = Post.objects.create(**validated_data)
image = self.context['image']
Image.objects.create(post=post.pk, image=image)
return post
But I need to do it using a serializer.

Answer 1

The easy way for this would be like:
Models:
from django.db import models
# Create your models here.
class Post(models.Model):
text = models.TextField()
def __str__(self):
return self.text[:50]
class Image(models.Model):
post = models.ForeignKey(
Post, on_delete=models.CASCADE,
related_name='images', editable=False
)
image = models.ImageField(upload_to='images/')
def __str__(self):
return self.image.name
def delete(self, *args, **kwargs):
self.image.delete()
super().delete(*args, **kwargs)
Serializer:
from rest_framework import serializers
from .models import Post, Image
class ImageSerializer(serializers.ModelSerializer):
class Meta:
model = Image
fields = "__all__"
class PostSerializer(serializers.ModelSerializer):
class Meta:
model = Post
fields = "__all__"
class PostWithImageSerializer(serializers.ModelSerializer):
image = serializers.ImageField(write_only=True)
# This is for the GET request or the response of the POST request
# We can also work with a separate serializer for such cases
images = ImageSerializer(many=True, read_only=True)
class Meta:
model = Post
fields = "__all__"
def create(self, validated_data):
image_data = validated_data.pop('image')
post = Post.objects.create(**validated_data)
Image.objects.create(post=post, image=image_data)
return post
Views as:
from rest_framework.response import Response
from rest_framework import status
from .serializers import *
# Create your views here.
class AddPostWithAnImageView(APIView):
serializer_class = PostWithImageSerializer
def post(self, request):
serializer = self.serializer_class(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
For testing purposes, please use Postman where you can upload images with so much ease. The request form should only require the text and the image fields.

Answer 2

Thanks to #pKiran, who gave me an idea, now I have a working code for saving one or more images. It's, also, quite concise and readable. There's quite a lot going on here with so little of code. Django REST is quite confusing.
class ImageSerializer(serializers.ModelSerializer):
class Meta:
model = Image
fields = ('image', 'thumb')
class NewPostSerializer(serializers.ModelSerializer):
image = serializers.ListField(child=serializers.ImageField(), write_only=True, required=False)
def create(self, validated_data):
images = validated_data.pop('image', None)
post = Post.objects.create(**validated_data)
if images:
img_models = [Image(post=post,
image=image, thumb=make_thumb(image))
for image in images]
Image.objects.bulk_create(img_models)
return post