How to add categories at my django blog

Question

I developed a django blog application using djangogirls.com tutorial. I am trying to add a blog category but I just can't do it!

I was searching google and stackoverflow.com like crazy , but , being a newbie in python/django I couldn't successfully add categories to my blog.

My models:

from django.db import models
from django.utils import timezone 

class Post(models.Model):
    author = models.ForeignKey('auth.User')
    title = models.CharField(max_length=200)
    text = models.TextField()
    created_date = models.DateTimeField(
          default=timezone.now)
    published_date = models.DateTimeField(
          blank=True, null=True)

def publish(self):
    self.published_date = timezone.now()
    self.save()

def __str__(self):
    return self.title

My views:

from django.shortcuts import render, get_object_or_404
from django.utils import timezone
from .models import Post

def post_list(request):
posts =  Post.objects.filter(published_date__lte=timezone.now()).order_by('published_date')
return render(request, 'blog/post_list.html', {'posts': posts})

def post_detail(request, pk):
    post = get_object_or_404(Post, pk=pk)
    return render(request, 'blog/post_detail.html', {'post': post})

My urls:

from django.conf.urls import include, url
from . import views

urlpatterns = [
    url(r'^$', views.post_list, name='post_list'),
    url(r'^post/(?P<pk>\d+)/$', views.post_detail, name='post_detail'),
]

My post_list.html: {% extends 'blog/base.html' %}

 {% block content %}
   {% for post in posts %}
      <div class="post">
          <div class="date">
              {{ post.published_date }}
          </div>
              <h1><a href="{% url 'post_detail' pk=post.pk %}">{{post.title }}</a></h1>
        <p>{{ post.text|truncatewords:100}}</p>
    </div>
  {% endfor %}
{% endblock %}

My post_detail.html:

{% extends 'blog/base.html' %}

{% block content %}
    <div class="post">
       {% if post.published_date %}
           <div class="date">
              {{ post.published_date }}
           </div>
      {% endif %}
      <h1>{{ post.title }}</h1>
    <p>{{ post.text|linebreaks }}</p>
 </div>
{% endblock %}

Ok. If somebody can help me out , I need to create a category model for this blog model ,I would really appreciate it ! Thanks in advance!

Answer 1

I'd go with

class Category(models.Model):
    title = models.CharField(max_length=255, verbose_name="Title")
    ...


class Post(models.Model):
    category = models.ForeignKey(Category, verbose_name="Category")
    title = models.CharField(max_length=255, verbose_name="Title")
    text = models.TextField()
    ...

When you have a post like this:

post = Post.objects.first()

you can access it's category's title with post.category.title or when you have a category like this:

category = Category.objects.first()

you can get the posts under that category with category.post_set.all().

---

I have edited your code to show how I'd write if that was a project I am working on. Here it is:

models.py

from django.db import models
from django.utils import timezone 

class Category(models.Model):
    created_at = models.DateTimeField(auto_now_add=True, verbose_name="Created at")
    updated_at = models.DateTimeField(auto_now=True, verbose_name="Updated at")
    title = models.CharField(max_length=255, verbose_name="Title")

    class Meta:
        verbose_name = "Category"
        verbose_name_plural = "Categories"
        ordering = ['title']

    def __str__(self):
        return self.title

class Post(models.Model):
    created_at = models.DateTimeField(auto_now_add=True, verbose_name="Created at")
    updated_at = models.DateTimeField(auto_now=True, verbose_name="Updated at")
    is_published = models.BooleanField(default=False, verbose_name="Is published?")
    published_at = models.DateTimeField(null=True, blank=True, editable=False, verbose_name="Published at")
    category = models.ForeignKey(Category, verbose_name="Category")
    author = models.ForeignKey('auth.User', verbose_name="Author")
    title = models.CharField(max_length=200, verbose_name="Title")
    text = models.TextField(verbose_name="Text")

    class Meta:
        verbose_name = "Post"
        verbose_name_plural = "Posts"
        ordering = ['-created_at']

    def publish(self):
        self.is_published = True
        self.published_at = timezone.now()
        self.save()

    def __str__(self):
        return self.title

views.py

from django.shortcuts import render, get_object_or_404
from django.utils import timezone
from .models import Category, Post

def category_list(request):
    categories = Category.objects.all() # this will get all categories, you can do some filtering if you need (e.g. excluding categories without posts in it)

    return render (request, 'blog/category_list.html', {'categories': categories}) # blog/category_list.html should be the template that categories are listed.

def category_detail(request, pk):
    category = get_object_or_404(Category, pk=pk)

    return render(request, 'blog/category_detail.html', {'category': category}) # in this template, you will have access to category and posts under that category by (category.post_set).

def post_list(request):
    posts =  Post.objects.filter(published_at__lte=timezone.now()).order_by('published_at')

    return render(request, 'blog/post_list.html', {'posts': posts})

def post_detail(request, pk):
    post = get_object_or_404(Post, pk=pk)

    return render(request, 'blog/post_detail.html', {'post': post})

urls.py

from django.conf.urls import include, url
from . import views

urlpatterns = [
    url(r'^category$', views.category_list, name='category_list'),
    url(r'^category/(?P<pk>\d+)/$', views.category_detail, name='category_detail'),
    url(r'^$', views.post_list, name='post_list'),
    url(r'^post/(?P<pk>\d+)/$', views.post_detail, name='post_detail'),
]

I didn't write templates, they are up to you.