I have a post model that represents a normal post with images and possibly a video. I have a post reply model that represents comments or replies to a post.
Here is the models.py file:
class Category(models.Model):
name = models.CharField(max_length=100, verbose_name="name")
slug = AutoSlugField(populate_from=["name"])
description = models.TextField(max_length=300)
parent = models.ForeignKey(
"self", on_delete=models.CASCADE, blank=True, null=True, related_name="children"
)
created_at = models.DateTimeField(auto_now_add=True, verbose_name="created at")
updated_at = models.DateTimeField(auto_now=True, verbose_name="updated at")
class Meta:
verbose_name = "category"
verbose_name_plural = "categories"
ordering = ["name"]
db_table = "post_categories"
def __str__(self):
return self.name
def get_absolute_url(self):
return self.slug
def video_directory_path(instance, filename):
return "{0}/posts/videos/{1}".format(instance.user.id, filename)
def post_directory_path(instance, filename):
return "posts/{0}/images/{1}".format(instance.post.id, filename)
def reply_directory_path(instance, filename):
return "replies/{0}/images/{1}".format(instance.reply.id, filename)
def reply_videos_directory_path(instance, filename):
return "{0}/posts/{1}/replies/{2}/videos/{3}".format(instance.user.id, instance.post.id, instance.reply.id, filename)
class Post(models.Model):
EV = "Everybody"
FO = "Followers"
FR = "Friends"
AUDIENCE = [
(EV, "Everybody"),
(FO, "Followers"),
(FR, "Friends"),
]
category = models.ForeignKey(Category, on_delete=models.SET_DEFAULT, default=1)
body = models.TextField("content", blank=True, null=True, max_length=5000)
slug = AutoSlugField(populate_from=["category", "created_at"])
video = models.FileField(upload_to=video_directory_path, null=True, blank=True)
can_view = models.CharField(max_length=10, choices=AUDIENCE, default=EV)
can_comment = models.CharField(max_length=10, choices=AUDIENCE, default=EV)
user = models.ForeignKey(
User, on_delete=models.CASCADE, verbose_name="user", related_name="user"
)
published = models.BooleanField(default=False)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
class Meta:
verbose_name = "post"
verbose_name_plural = "posts"
db_table = "posts"
ordering = ["created_at"]
def __str__(self):
return self.body[0:30]
def get_absolute_url(self):
return self.slug
class PostImage(models.Model):
post = models.ForeignKey(Post, on_delete=models.CASCADE, related_name="images")
image = models.FileField(
upload_to=post_directory_path, default="posts/default.png", null=True
)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
class Meta:
db_table = "post_images"
ordering = ["post"]
def __str__(self):
return self.post
def image_tag(self):
return mark_safe(
'<img src="/storage/%s" width="50" height="50" />' % (self.image)
)
image_tag.short_description = "Image"
class Reply(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
post = models.ForeignKey(Post, on_delete=models.CASCADE)
video = models.FileField(
upload_to=reply_videos_directory_path, null=True, blank=True
)
body = models.TextField(max_length=256, default=None)
parent = models.ForeignKey(
"self", on_delete=models.CASCADE, null=True, blank=True, related_name="replies"
)
created_at = models.DateTimeField(auto_now_add=True, verbose_name="Created at")
updated_at = models.DateTimeField(auto_now=True, verbose_name="Updated at")
class Meta:
verbose_name = "post reply"
verbose_name_plural = "post replies"
db_table = "post_reply"
def __str__(self):
return self.reply[0:30]
I have the following serializers to deal with the posts and the replies:
class PostImageSerializer(serializers.ModelSerializer):
class Meta:
model = PostImage
fields = ["id", "image", "post"]
extra_kwargs = {
"post": {"required": True},
}
class PostSerializer(serializers.ModelSerializer):
images = PostImageSerializer(many=True, read_only=True, required=False)
profile = serializers.SerializerMethodField()
class Meta:
model = Post
fields = [
"id",
"can_view",
"can_comment",
"category",
"body",
"images",
"video",
"profile",
"published",
"created_at",
"updated_at",
]
depth = 1
def get_profile(self, obj):
profile_obj = Profile.objects.get(id=obj.user.profile.id)
profile = ShortProfileSerializer(profile_obj)
return profile.data
def create(self, validated_data):
user = User.objects.get(id=self.context['request'].data.get('user'))
category = Category.objects.get(id=self.context['request'].data.get('category'))
new_post = Post.objects.create(**validated_data, category=category, user=user)
images = dict((self.context['request'].FILES).lists()).get('images', None)
if images:
for image in images:
PostImage.objects.create(
image=image, post=new_post
)
return new_post
def update(self, id):
breakpoint()
post = Post.object.all().filter(id=id)
class ReplyImageSerializer(serializers.ModelSerializer):
class Meta:
model = ReplyImage
fields = ["id", "image", "reply"]
extra_kwargs = {
"reply": {"required": True},
}
class ReplySerializer(serializers.ModelSerializer):
images = ReplyImageSerializer(many=True, read_only=True, required=False)
profile = serializers.SerializerMethodField()
post_images = serializers.SerializerMethodField(many=True)
class Meta:
model = Reply
fields = [
"id",
"post",
"post_images",
"video",
"images",
"body",
"parent",
"profile",
"created_at",
"updated_at",
]
depth = 1
def get_profile(self, obj):
profile_obj = Profile.objects.get(id=obj.user.profile.id)
profile = ShortProfileSerializer(profile_obj)
return profile.data
def get_post_images(self, obj):
post_obj = PostImage.objects.get(post=obj.post.id)
post_images = ShortProfileSerializer(post_obj)
return post_images.data
def create(self, validated_data):
new_reply = Reply.objects.create(**validated_data)
images = dict((self.context['request'].FILES).lists()).get('images', None)
if images:
for image in images:
ReplyImage.objects.create(
image=image, reply=new_reply
)
return new_reply
I use the following view to see a specific reply to a post but the related images are missing and I would like to get the related images into the endpoint. I would also like to get the category name and display that instead of the id, but images for now are more important.
I have added a serializer method field to the reply serializer to get the post images into the end point and it gets the images but it gives me an error:
get() returned more than one PostImage -- it returned 4!
Is there something I can do to get multiple objects from a serializer method field, to include in the endpoint or should I use a different approach?
Also how can I get the post category name instead of the ID?
Thank you
CodePudding user response：
Use filter() method instead of get(), and pass the resulting QuerySet object to the serializer class with many=True
class ReplySerializer(serializers.ModelSerializer):
...
post_images = serializers.SerializerMethodField()
class Meta:
model = Reply
fields = [
"...",
"post_images",
]
depth = 1
def get_post_images(self, obj):
images = PostImage.objects.filter(post=obj.post.id)
serializer = PostImageSerializer(images, many=True)
return serializer.data