How can I customize url output? - django

Question

I'm building a site using Django for equipment management. I am currently using this tutorial to help me get started.
I would like for the url displaying in the url bar in a browser to show something such as:
127.0.0.1:8000/catalog/model/model_number
But at the moment it just shows a single integer like 1, 2, 3, etc. when I click on each individual model.
Here is my urls.py:
from django.urls import path
from . import views
urlpatterns = [
path('', views.index, name='index'),
path('books/', views.BookListView.as_view(), name='books'),
path('book/<int:pk>', views.BookDetailView.as_view(), name='book-detail'),
path('models/', views.ModelListView.as_view(), name='models'),
path('model/<int:pk>', views.ModelDetailView.as_view(), name='model-detail'),
]
I know that path('model/<int:pk>'... is the part that should be changed. I've tried path('model/model.model_number>'... but this outputs the below error:
Reverse for 'model-detail' with arguments '('2',)' not found. 1 pattern(s) tried: ['catalog\\/model\\/\\<model\\.model_number\\>$']
Here is my models.py:
from django.db import models
from django.urls import reverse #Used to generate URLs by reversing the URL patterns
import uuid
import datetime
# Create your models here.
class Genre(models.Model):
"""Model representing book genre"""
name = models.CharField(max_length = 200, help_text = 'Enter book genre')
def __str__(self):
"""String for represnting model object."""
return self.name
class Book(models.Model):
"""Model representing a book (but not a specific copy of a book)"""
title = models.CharField(max_length = 200)
author = models.ForeignKey('Author', on_delete = models.SET_NULL, null = True)
# Foreign Key used because book can only have one author, but authors can have multiple books
# Author as a string rather than object because it hasn't been declared yet in the file.
summary = models.TextField(max_length = 1000, help_text = 'Enter brief descp. of book') #TextField for longer descp.
isbn = models.CharField('ISBN', max_length = 13, help_text = '13 character ISBN number')
#ManyToManyField used because genre can contain many books. Books can cover many genres.
#Genre class has already been defined so we can specify the object above.
genre = models.ManyToManyField(Genre, help_text = 'Select genre for this book') #Genre capitalized, calling model up
def __str__(self):
"""String for representing the Model object."""
return self.title
def get_absolute_url(self):
"""returns the URL to access a detail record for this book."""
return reverse('book-detail', args=[str(self.id)])
class BookInstance(models.Model):
"""Model representing a specific copy of a book"""
id = models.UUIDField(primary_key = True, default = uuid.uuid4, help_text = 'Unique ID for this book across whole library')
book = models.ForeignKey('Book', on_delete=models.SET_NULL, null = True)
imprint = models.CharField(max_length = 200)
due_back = models.DateField(null = True, blank = True) #could do date scanned (date.now())
LOAN_STATUS = ( #could be ownership! Or make more of these for location
('m', 'Maintenance'), #being worked on, cleaned after field
('o', 'On loan'), #in the field
('a', 'Available'), #ready to go
('r', 'Reserved'), #in the field, could add one for 'being tested'
)
status = models.CharField(
max_length = 1,
choices = LOAN_STATUS,
blank = True,
default = 'm',
help_text = 'Book availability',
)
class Meta:
ordering = ['due_back']
def __str__(self):
"""String for representing the Model object."""
return f'{self.id} ({self.book.title})' #Will pop up on admin page as this
class Author(models.Model):
"""Model representing an author"""
first_name = models.CharField(max_length = 100)
last_name = models.CharField(max_length = 100)
date_of_birth = models.DateField(null = True, blank = True)
date_of_death = models.DateField('Died', null = True, blank = True)
class Meta:
ordering = ['last_name', 'first_name']
def get_absolute_url(self):
"""Returns the url to access a particular author instance."""
return reverse('author-detail', args=[str(self.id)])
def __str__(self):
"""String for representing the Model object."""
return f'{self.last_name}, {self.first_name}' #Will pop up on admin page as this
class Location(models.Model):
town_city_base = models.CharField('Town/City/Base', max_length = 25, help_text="If location is classified enter CLASSIFIED in CAPS")
state = models.CharField(max_length = 25)
country = models.CharField(max_length = 25)
class Meta:
ordering = ['town_city_base', 'state', 'country']
def get_absolute_url(self):
#Returns the url to access a particular location instance
return reverse('location-detail', args=[str(self.id)])
def __str__(self):
#String for representing the Model object
return f'{self.town_city_base}, {self.state}, {self.country}'
class Category(models.Model):
category = models.CharField('Equipment Type', max_length = 50, help_text = "Enter general category of equipment")
class Meta:
verbose_name_plural = "categories" #default would have shown as "Categorys" on admin page
def __str__(self):
return self.category
class Manufacturer(models.Model):
manufacturer = models.CharField(max_length = 50, help_text = "Original manufacturer or supplier")
def __str__(self):
return self.manufacturer
class Model(models.Model):
model_number = models.CharField('Model Number', max_length = 50)
manufacturer = models.ForeignKey('Manufacturer', on_delete = models.SET_NULL, null = True)
category = models.ForeignKey('Category', on_delete = models.SET_NULL, null = True)
description = models.TextField(max_length = 1000, help_text = "Enter brief description of product", null = True) #TextField for longer descriptions
def __str__(self):
return f'{self.model_number}..........{self.description}'
def get_absolute_url(self):
#Returns the url to access a particular location instance
return reverse('model-detail', args=[str(self.id)])
class Ownership(models.Model):
ownership = models.CharField('Ownership', max_length = 50)
class Meta:
verbose_name_plural = "Owners"
def __str__(self):
return self.ownership
def get_absolute_url(self):
return reverse('ownership-detail', args=[str(self.id)])
class ModelInstance(models.Model):
asset = models.CharField('Asset Number', max_length = 50, help_text = "Enter Weston or Government I.D. Tag Number")
model = models.ForeignKey('Model', on_delete = models.SET_NULL, null = True, help_text = "Leave blank if no model number exists")
serial = models.CharField('Serial Number', max_length = 50, null = True, blank = True, help_text = "Leave blank if no serial number exists")
location = models.ForeignKey('Location', on_delete = models.SET_NULL, null = True, help_text = "Enter current location or location after manufacturing")
ownership = models.ForeignKey('Ownership', on_delete = models.SET_NULL, null = True, help_text = "Enter current owner of equipment")
STATUS = (
('M', 'Maintenance'), #being worked on, not available
('D', 'Deployed'), #in the field
('A', 'Available'), #ready to go
('R', 'Reserved'), #Being used for classified/other project
('K', 'Broken'), #Broken
)
status = models.CharField(
max_length = 1,
choices = STATUS,
blank = True,
default = 'A',
help_text = 'Equipment Availability',
)
note = models.TextField('Notes', max_length = 1000, null = True, blank = True)
date_added = models.DateField("Date Added", default=datetime.date.today)
def __str__(self):
return f'Asset Number: {self.asset}..........Serial Number: {self.serial}..........Location: {self.location}..........Ownership: {self.ownership}'

Answer 1

You don't use the url to access the model's fields so
model.model_number>
is not going to help you.
If you want this url:
/catalog/model/model_number
You have to code it literally as it is:
path('catalog/model/model_number/<int:pk>/', views.ModelDetailView.as_view(), name='model-detail'),
]
It is good practice to add a backlash to the end.
Bear in mind that if the app name is catalog it is not necessary to add it to the path.
Now the pk of course is necessary to be passed to the view to retrieve the object you want, so you'll have this url in the browser:
127.0.0.1:8000/catalog/model/model_number/1/