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tried to connect a ModelForm

i am reciving a "value error"
because of "ModelForm has no model class specified."
i tried to check the : models.py forms.py and views.py but all looks pretty good for me
views.py :
class CreatePostView(LoginRequiredMixin,CreateView):
login_url='/login/'
redirect_field_name='Myblog/post_detail.html'
form_class = PostForm
model = Post
models.py:
class Post(models.Model):
author = models.ForeignKey('auth.User',on_delete=models.CASCADE)
title = models.CharField(max_length=200)
text = models.TextField()
created_date = models.DateTimeField(default=timezone.now)
published_date = models.DateTimeField(blank=True,null=True)
forms.py:
class PostForm(ModelForm):
class meta:
model = Post
fields = ('author','title','text')
from app.urls.py
url(r'^post/new/$',views.CreatePostView.as_view(),name='post_new'),

Meta is with an uppercase, according to PEP-8 the names of classes all start with an uppercase. In your form, you should write:
# app/forms.py
class PostForm(ModelForm):
class Meta:
model = Post
fields = ('author','title','text')
Since you wrote it as meta, Django indeed did not understand what model you were using.
If you however do not write a form with specific items, you can - like #DanielRoseman says, just define this at the CreateView [Django-doc]:
class CreatePostView(LoginRequiredMixin,CreateView):
login_url='/login/'
redirect_field_name='Myblog/post_detail.html'
model = Post
fields = ('author', 'title', 'text')
Django can construct a form class through the modelform_factory [Django-doc].

Django rest framework displaying specific field of a model

In my model:
from django.contrib.auth.models import User
class Restaurant(models.Model):
manager = models.ForeignKey(User, on_delete=models.PROTECT,
null=True, blank=False, related_name="manager")
in my serializers.py
class RestaurantSerializer(CoreHyperlinkedModelSerializer):
class Meta:
model = Restaurant
in my views.py
class RestaurantViewSet(viewsets.ModelViewSet):
queryset = Restaurant.objects.order_by('id').all()
serializer_class = RestaurantSerializer
on my list:
the manager is displaying as <rest_framework.relations.PKOnlyObject object at 0x9f7040xbc208>
How can I display it as normal data like its username?

You want to use a 'SlugRelatedField'.

There are a few ways you can go, but if you just want to show a username, all you need is this
from rest_framework import serializers
class RestaurantSerializer(serializers.ModelSerializer):
manager = serializers.CharField(source="manager.username")
class Meta:
model = Restaurant
if you inherit from ModelSerializer and skip the manager field, it will use user PK as the value of the manager field by default.
a slightly more involved way would be to define a separate serializer for User and then embed it in RestaurantSerializer.
from rest_framework import serializers
class UserSerializer(serializers.ModelSerializer):
class Meta:
model = User
class RestaurantSerializer(serializers.ModelSerializer):
manager = UserSerializer()
class Meta:
model = Restaurant
And if you really want to use hyperlinked serializer, you need to do quite a bit of work. You need to read this part carefully http://www.django-rest-framework.org/api-guide/serializers/#how-hyperlinked-views-are-determined

ForiegnKey field serializer in Django Rest framework

Before posting this question I've read few questions on SOF. but they are from 2012 and very confusing as well.
for e.g Django Rest Framework - Get related model field in serializer
my question is very straight forward
models.py
class User(models.Model):
username = models.CharField(max_length=100,unique=True)
password = models.CharField(max_length=100,null=False,blank=False)
class Car(models.Model):
user = models.ForeignKey(User)
car_name = models.CharField(max_length=100,null=True,blank=True)
serializers.py
class UserSerializer(serializers.ModelSerializer):
class Meta:
model = User
fields = ('username','password' )
class CarSerializer(serializers.ModelSerializer):
#user = ?? what should I write or is there any better approach for serializing Car objects
class Meta:
model = Car
fields = ('user','car_name')
views.py
class UserViewSet(viewsets.ModelViewSet):
queryset = User.objects.all()
serializer_class = UserSerializer
class CarViewSet(viewsets.ModelViewSet):
queryset = Car.objects.all()
serializer_class = CarSerializer
Please suggest all possible approaches.
1 more query. which one is better ModelSerializer or HyperlinkModelSerializer. as I saw different different answers containing these two.

You just need to do:
class CarSerializer(serializers.ModelSerializer):
user = UserSerializer()
class Meta:
model = Car
fields = ('user','car_name')
that is all.
Also, you should take a look to the kindnesses of serializers.Field and serializers.SerializerMethodField, you can play with them and customize your response data as much as you wish.
As to the question around HyperlinkedModelSerializer-ModelSerializer, very clear here:
The HyperlinkedModelSerializer has the following differences from ModelSerializer:
It does not include the pk field by default.
It includes a url field, using HyperlinkedIdentityField.
Relationships use HyperlinkedRelatedField, instead of PrimaryKeyRelatedField.
Hope that helps.

Django rest framework auto-populate filed with user.id

I cant find a way to auto-populate the field owner of my model.I am using the DRF .If i use ForeignKey the user can choose the owner from a drop down box , but there is no point in that.PLZ HELP i cant make it work.The views.py is not include cause i think there is nothing to do with it.
models.py
class Note(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
cr_date = models.DateTimeField(auto_now_add=True)
owner = models.CharField(max_length=100)
# also tried:
# owner = models.ForeignKey(User, related_name='entries')
class Meta:
ordering = ('-cr_date',)
def __unicode__(self):
return self.title
serializers.py
class UserSerializer(serializers.ModelSerializer):
class Meta:
model = User
fields = ('id', "username", 'first_name', 'last_name', )
class NoteSerializer(serializers.ModelSerializer):
owner = request.user.id <--- wrong , but is what a need.
# also tried :
# owner = UserSerializer(required=True)
class Meta:
model = Note
fields = ('title', 'body' )

Django Rest Framework provides a pre_save() method (in generic views & mixins) which you can override.
class NoteSerializer(serializers.ModelSerializer):
owner = serializers.Field(source='owner.username') # Make sure owner is associated with the User model in your models.py
Then something like this in your view class:
def pre_save(self, obj):
obj.owner = self.request.user
REFERENCES
http://www.django-rest-framework.org/tutorial/4-authentication-and-permissions#associating-snippets-with-users
https://github.com/tomchristie/django-rest-framework/issues/409#issuecomment-10428031

Django Admin: Ordering of ForeignKey and ManyToManyField relations referencing User

I have an application that makes use of Django's UserProfile to extend the built-in Django User model. Looks a bit like:
class UserProfile(models.Model):
user = models.ForeignKey(User, unique=True)
# Local Stuff
image_url_s = models.CharField(max_length=128, blank=True)
image_url_m = models.CharField(max_length=128, blank=True)
# Admin
class Admin: pass
I have added a new class to my model:
class Team(models.Model):
name = models.CharField(max_length=128)
manager = models.ForeignKey(User, related_name='manager')
members = models.ManyToManyField(User, blank=True)
And it is registered into the Admin:
class TeamAdmin(admin.ModelAdmin):
list_display = ('name', 'manager')
admin.site.register(Team, TeamAdmin)
Alas, in the admin inteface, when I go to select a manager from the drop-down box, or set team members via the multi-select field, they are ordered by the User numeric ID. For the life of me, I can not figure out how to get these sorted.
I have a similar class with:
class Meta:
ordering = ['name']
That works great! But I don't "own" the User class, and when I try this trick in UserAdmin:
class Meta:
ordering = ['username']
I get:
django.core.management.base.CommandError: One or more models did not validate:
events.userprofile: "ordering" refers to "username", a field that doesn't exist.
user.username doesn't work either. I could specify, like image_url_s if I wanted to . . . how can I tell the admin to sort my lists of users by username? Thanks!

This
class Meta:
ordering = ['username']
should be
ordering = ['user__username']
if it's in your UserProfile admin class. That'll stop the exception, but I don't think it helps you.
Ordering the User model as you describe is quite tricky, but see http://code.djangoproject.com/ticket/6089#comment:8 for a solution.

One way would be to define a custom form to use for your Team model in the admin, and override the manager field to use a queryset with the correct ordering:
from django import forms
class TeamForm(forms.ModelForm):
manager = forms.ModelChoiceField(queryset=User.objects.order_by('username'))
class Meta:
model = Team
class TeamAdmin(admin.ModelAdmin):
list_display = ('name', 'manager')
form = TeamForm

This might be dangerous for some reason, but this can be done in one line in your project's models.py file:
User._meta.ordering=["username"]

For me, the only working solution was to use Proxy Model. As stated in the documentation, you can create own proxy models for even built-in models and customize anything like in regular models:
class OrderedUser(User):
class Meta:
proxy = True
ordering = ["username"]
def __str__(self):
return '%s %s' % (self.first_name, self.last_name)
After that, in your model just change Foreign Key to:
user = models.OneToOneField(OrderedUser, unique=True)
or even more suitable
user = models.OneToOneField(OrderedUser, unique = True, parent_link = True)