Django REST Framework - Class UserSerializer missing "Meta.model" attribute

13,754

Solution 1

As in comment replace module to model

class UserSerializer(serializers.ModelSerializer):
    """
    Because 'snippets' is a reverse relationship on the User model,
    it will not be included by default when using the ModelSerializer class,
    so we needed to add an explicit field for it.
    """
    snippets = serializers.PrimaryKeyRelatedField(
        many=True, queryset=Snippet.objects.all())

    class Meta:
        model = User
        #^^^^^^

Solution 2

This is a common occurrence when you miss the subclass Meta: attributes, in my case it was

class RegisterSerializer(serializers.ModelSerializer):
class Meta:
model: User
    fields: ('id', 'username', 'email', 'password')
    extra_kwargs = {'password': {'write_only': True}}

I am using colon(:) instead of equals to(=) to set the subclass Meta attributes

class RegisterSerializer(serializers.ModelSerializer):
class Meta:
model = User
    fields = ('id', 'username', 'email', 'password')
    extra_kwargs = {'password': {'write_only': True}}

Attributes assign variables using (=) not (:)

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13,754
Belter
Author by

Belter

Updated on June 09, 2022

Comments

  • Belter
    Belter almost 2 years

    I am following the tutorial of Django REST Framework, all is well until part 4 - Authentication & Permissions -> Adding login to the Browsable API, I want to browser the users I have created through url http://localhost:8024/users/.

    But I get this error message:

    AssertionError at /users/
    Class UserSerializer missing "Meta.model" attribute
    Request Method: GET
    Request URL:    http://localhost:8024/users/
    Django Version: 1.10
    Exception Type: AssertionError
    Exception Value:    
    Class UserSerializer missing "Meta.model" attribute
    Exception Location: C:\Python27\lib\site-packages\rest_framework\serializers.py in get_fields, line 976
    Python Executable:  C:\Python27\python.exe
    Python Version: 2.7.11
    Python Path:    
    ['D:\\github\\py2\\dj-rest\\tutorial',
     'C:\\Windows\\system32\\python27.zip',
     'C:\\Python27\\DLLs',
     'C:\\Python27\\lib',
     'C:\\Python27\\lib\\plat-win',
     'C:\\Python27\\lib\\lib-tk',
     'C:\\Python27',
     'C:\\Python27\\lib\\site-packages']
    Server time:    Thu, 10 Aug 2017 11:41:38 +0000
    

    But I do have class Meta in my UserSerializer class as showing in "serializers.py" file, please have a look and give me a help.

    Serializer.py

    # serializers.py
    from rest_framework import serializers
    from snippets.models import Snippet
    from django.contrib.auth.models import User
    class SnippetSerializer(serializers.ModelSerializer):
        # add a new field
        owner = serializers.ReadOnlyField(source='owner.username')
    
    class Meta:
        model = Snippet
        fields = ('id', 'title', 'code', 'file',
                  'linenos', 'language', 'style', 'owner')
    
    
    class UserSerializer(serializers.ModelSerializer):
        """
        Because 'snippets' is a reverse relationship on the User model,
        it will not be included by default when using the ModelSerializer class,
        so we needed to add an explicit field for it.
        """
        snippets = serializers.PrimaryKeyRelatedField(many=True,
    
    
    queryset=Snippet.objects.all())
    
        class Meta:
            module = User
            fields = ('id', 'username', 'snippets')
    

    models.py

    from __future__ import unicode_literals
    
    from django.db import models
    from pygments.lexers import get_all_lexers, get_lexer_by_name
    from pygments.styles import get_all_styles
    from pygments.formatters.html import HtmlFormatter
    from pygments import highlight
    
    LEXERS = [item for item in get_all_lexers() if item[1]]
    LANGUAGE_CHOICES = sorted([(item[1][0], item[0]) for item in LEXERS])
    STYLE_CHOICES = sorted((item, item) for item in get_all_styles())
    
    
    # Create your models here.
    class Snippet(models.Model):
        created = models.DateTimeField(auto_now_add=True)
        title = models.CharField(max_length=100, blank=True, default='')
        code = models.TextField()
        file = models.FileField()
        linenos = models.BooleanField(default=False)
        language = models.CharField(choices=LANGUAGE_CHOICES, default='python', max_length=100)
        style = models.CharField(choices=STYLE_CHOICES, default='friendly', max_length=100)
        owner = models.ForeignKey('auth.User', related_name='snippets', on_delete=models.CASCADE)
        highlighted = models.TextField()
    
        class Meta:
            ordering = ('created',)
    
        def save(self, *args, **kwargs):
            """
            Use the `pygments` library to create a highlighted HTML
            representation of the code snippet.
            """
            lexer = get_lexer_by_name(self.language)
            linenos = self.linenos and 'table' or False
            options = self.title and {'title': self.title} or {}
            formatter = HtmlFormatter(style=self.style, linenos=linenos,
                                      full=True, **options)
            self.highlighted = highlight(self.code, lexer, formatter)
            super(Snippet, self).save(*args, **kwargs)
    

    views.py

    from snippets.models import Snippet
    from snippets.serializers import SnippetSerializer, UserSerializer
    from rest_framework import generics
    from django.contrib.auth.models import User  # for authentication and permissions
    from rest_framework import permissions
    
    class SnippetList(generics.ListCreateAPIView):
        """
        get -> list;
        post -> create;
        """
        permission_classes = (permissions.IsAuthenticatedOrReadOnly,)
        queryset = Snippet.objects.all()
        serializer_class = SnippetSerializer
    
        def perform_create(self, serializer):
            serializer.save(owner=self.request.user)
    
    
    class SnippetDetail(generics.RetrieveUpdateDestroyAPIView):
        """
        get -> retrieve;
        put -> update;
        delete -> destroy;
        """
        permission_classes = (permissions.IsAuthenticatedOrReadOnly,)
        queryset = Snippet.objects.all()
        serializer_class = SnippetSerializer
    
    
    class UserList(generics.ListAPIView):
        queryset = User.objects.all()
        serializer_class = UserSerializer
    
    
    class UserDetail(generics.RetrieveAPIView):
        queryset = User.objects.all()
        serializer_class = UserSerializer
    

    snippets/urls.py

    from django.conf.urls import url
    from rest_framework.urlpatterns import format_suffix_patterns
    from snippets import views
    
    urlpatterns = [
        url(r'^snippets/$', views.SnippetList.as_view()),
        url(r'^snippets/(?P<pk>[0-9]+)/$', views.SnippetDetail.as_view()),
        url(r'^users/$', views.UserList.as_view()),
        url(r'^users/(?P<pk>[0-9]+)/$', views.UserDetail.as_view()),
    ]
    
    # Adding optional format suffixes to our URLs
    urlpatterns = format_suffix_patterns(urlpatterns)