Django: Getting "Page not found" Error While Using Slug in URL - django

Question

I am a beginner learning Django through a building an app, called PhoneReview. It will store reviews related to the latest mobile phone. It will also display phone brands, along with the associated phone models and their reviews.
Right now, I am facing an error just after I have added codes to use slug in the URLs. When I go to http://127.0.0.1:8000/index, I see this page:
When I click on "Samsung," I get this error:
Page not found (404)
Request Method: GET
Request URL: http://127.0.0.1:8000/index/samsung/
Raised by: PhoneReview.views.ModelView
No phone model found matching the query
You're seeing this error because you have DEBUG = True in your Django settings file. Change that to False, and Django will display a standard 404 page.
I have successfully performed migration. But still, I am facing the issue.
Here are my codes of models.py located inside PhoneReview folder:
from django.db import models
from django.template.defaultfilters import slugify
# Create your models here.
class Brand(models.Model):
brand_name = models.CharField(max_length=100)
origin = models.CharField(max_length=100)
manufacturing_since = models.CharField(max_length=100, null=True, blank=True)
slug = models.SlugField(unique=True, max_length=150)
def __str__(self):
return self.brand_name
def save(self, *args, **kwargs):
self.slug = slugify(self.brand_name)
super().save(*args, **kwargs)
class PhoneModel(models.Model):
brand = models.ForeignKey(Brand, on_delete=models.CASCADE)
model_name = models.CharField(max_length=100)
launch_date = models.CharField(max_length=100)
platform = models.CharField(max_length=100)
slug = models.SlugField(unique=True, max_length=150)
def __str__(self):
return self.model_name
def save(self, *args, **kwargs):
self.slug = slugify(self.model_name)
super().save(*args, **kwargs)
class Review(models.Model):
phone_model = models.ManyToManyField(PhoneModel, related_name='reviews')
review_article = models.TextField()
date_published = models.DateField(auto_now=True)
slug = models.SlugField(max_length=150, null=True, blank=True)
link = models.TextField(max_length=150, null=True, blank=True)
def __str__(self):
return self.review_article
Here are my codes of urls.py located inside PhoneReview folder:
from . import views
from django.urls import path
app_name = 'PhoneReview'
urlpatterns = [
path('index', views.BrandListView.as_view(), name='brandlist'),
path('index/<slug:slug>/', views.ModelView.as_view(), name='modellist'),
path('details/<slug:slug>/', views.ReviewView.as_view(), name='details'),
]
Here are my codes of views.py located inside PhoneReview folder:
from django.shortcuts import render
from django.views import generic
from .models import Brand, PhoneModel, Review
class BrandListView(generic.ListView):
template_name = 'PhoneReview/index.html'
context_object_name = 'all_brands'
def get_queryset(self):
return Brand.objects.all()
class ModelView(generic.DetailView):
model = PhoneModel
template_name = 'PhoneReview/phonemodel.html'
context_object_name = 'phonemodel'
class ReviewView(generic.DetailView):
model = Review
template_name = 'PhoneReview/details.html'
Here are my codes of apps.py located inside PhoneReview folder:
from django.apps import AppConfig
class PhonereviewConfig(AppConfig):
name = 'PhoneReview'
Here are my codes of index.html located inside templates folder:
{% extends 'PhoneReview/base.html' %}
{% load static %}
{% block title%}
Brand List
{% endblock %}
{% block content %}
<!--Page content-->
<h1>This is Brand List Page</h1>
<h2>Here is the list of the brands</h2>
<ul>
{% for brand in all_brands %}
<!-- <li>{{ brand.brand_name }}</li>-->
<li>{{ brand.brand_name }}</li>
{% endfor %}
</ul>
<img src="{% static "images/brandlist.jpg" %}" alt="Super Mario Odyssey" /> <!-- New line -->
{% endblock %}
Here are my codes of phonemodel.html located inside templates folder:
{% extends 'PhoneReview/base.html' %}
{% load static %}
{% block title%}
Phone Model Page
{% endblock %}
{% block content %}
<!--Page content-->
<h1>This is Phone Model Page</h1>
<h2>Here is the phone model</h2>
<ul>
<li>{{ phonemodel.model_name }}</li>
</ul>
<img src="{% static "images/brandlist.jpg" %}" alt="Super Mario Odyssey" /> <!-- New line -->
{% endblock %}
Here are my codes of details.html located inside templates folder:
{% extends 'PhoneReview/base.html' %}
{% load static %}
<html>
<link rel="stylesheet" type="text/css" href="{% static "css/style.css" %}">
<html lang="en">
{% block title%}Details{% endblock %}
{% block content %}
<h1>This is the Details Page</h1>
<h2>Review:</h2>
<p>{{ review.review_article }}</p>
<h2>News Link:</h2>
<p>{{ review.link }}</p>
{% endblock %}
</html>
I feel that I have made a mistake on either index.html or phonemodel.html. But being a beginner, I can't catch it.
How can I fix the issue?
Update: I added the following codes in phonemodel.html to loop over phone models, as suggested by #c.grey :
<ul>
{% for model_name in all_model_name %}
<li>{{ phonemodel.model_name }}</li>
{% endfor %}
</ul>
Also, I added this line in index.html:
<li>{{ brand.brand_name }}</li>
Moreover, I added these codes in views.py:
class ModelView(generic.ListView):
template_name = 'PhoneReview/phonemodel.html'
context_object_name = 'all_model_name'
def get_queryset(self):
return PhoneModel.objects.all()
But now, I am getting this error:
django.urls.exceptions.NoReverseMatch: Reverse for 'modellist' with arguments '('',)' not found. 1 pattern(s) tried: ['index/(?P<slug>[-a-zA-Z0-9_]+)/$']
Here is the link to my project files:
https://github.com/shawnmichaels583583/phoneradar

Answer 1

Basically you are passing Brand model slug to get PhoneModel model data.
To get details from PhoneModel you need to pass PhoneModel slug to get data

Answer 2

Your error is that your link points to brand.slug (here samsung) but it seems to me that you don't have any phone model whose name is just samsung, do you?
You mix up brands and phone models