Login / Autos CRUD

This assignment is to build a fully working CRUD (Create, Read, Update, and Delete) application to manage automobiles and their makes (i.e. Ford, Hyundai, Toyota, Tata, Audi, etc.).

This application will be based on this folder in the samples repo:

https://github.com/csev/dj4e-samples/tree/master/autos

Do not clone this repository for this assignment. You will make a new project and application in your django_projects folder and use this application as sample code.

This application will be similar to:

https://crud.dj4e.com

The login information is as follows:

Account: dj4e-crud
Password: dj4e_nn_!

The 'nn' is a 2-digit number that by now, you should be able to easily guess.

Making a New Application

Activate any virtual environment you need (if any) and go into your django_projects folder and start a new application in your mysite project (this project already should have the 'hello' application from a previous assignment).

workon django3  # as needed
cd ~/django_projects/mysite
python manage.py startapp autos

Extending the home (i.e. main) page

Since we will build a number of applications in this project, we will use the home application to provide convienent urls to switch between applications.

And you should have a file mysite/home/templates/home/main.html that has the text for the top-level page. You can keep the "Hello World" text in the page somewhere.

Add a link to the "/autos" url in mysite/home/templates/home/main.html and anything else the autograder needs:

<li><a href="/autos">Autos CRUD</a>

It is a list because we will be adding more applications in future assignments. :)

Building the Autos Application

The essense of this task is to adapt the code from:

https://github.com/csev/dj4e-samples/tree/master/autos

and make it work in your autos project. As always there is a lot of code in dj4e-samples - be careful copying - and only copy code when you know why you are copying it. Go slowly.

Here are some tasks:

• Go into your dj4e-samples folder and do a git pull to get the latest version of the samples code.

• Create mysite/home/templates and mysite/home/templates/registration folders using mkdir and copy the (login.html) template from dj4e-samples into mysite/home/templates/registration/login.html.

• Copy the file from dj4e-samples/home/templates/base_bootstrap.html into your mysite/home/templates - this will be used in your autos/templates and make our HTML look better by applying the Bootstrap and other styling libraries.

• Edit mysite/mysite/settings.py add the autos application to the list of INSTALLED_APPS. You can follow the pattern of the HomeConfig line in that file.

• Edit mysite/mysite/urls.py and add the accounts/ path so you can use the Django built in login features. (Authentication Views). Also edit mysite/mysite/urls.py to route autos/ urls to autos/urls.py file.

  path('accounts/', include('django.contrib.auth.urls')),  # Add
  path('autos/', include('autos.urls')),                   # Add

• Edit the autos/urls.py file to add routes for the list, edit, and delete pages for both autos and makes

• Edit the autos/views.py file to add views for the list, edit, and delete pages for both autos and makes. It will make things a lot simpler in the long run if you convert the Make views to the shorter form like the Auto views. (Example)

• In your views.py file, you should not simply use the code for the Make views. You should rewrite the Make views using the same patterns as the Auto views. If you don't use the generic edit views on your Make views you will need to define the appropriate MakeForm in your forms.py just like in the sample code. The best approach is to build your views.py without using a forms.py - but you can do it either way.

• Run the python manage.py check until you see no errors

• Edit the autos/models.py file to add Auto and Makes models with a foreign key from Autos to Makes.

• Run the python manage.py makemigrations until it has no errors. If you find that the migrations have partially completed and seems ot be confused, you can always start the migrations over by typing:

  rm */migrations/00*.py

• Run the python manage.py migrate to create the database.

• Edit autos/admin.py to add the Auto and Make models to the Django administration interface.

• Run the python manage.py check until you see no errors

• Create a superuser so you can test the admin interface and log in to the application.

• Create the necessary template files in autos/templates/autos to support your views. Note that the the second sub folder under templates is there to make sure that templates are not inadvertently shared across multiple applications within a Django project.

• Find the line in your base_bootstrap.html that looks like this:

  <meta name="dj4e-code" content="99999999">

  and change the 9999999 to be "missing"

Make sure to check the autograder for additional markup requirements.

Things that can go wrong

If you ever get a 405 error on a Django page it probably means that you have defined a view class that does not have a get() method. For example if you meant to say this:

class AutoUpdate(LoginRequiredMixin, UpdateView):
    model = Auto
    fields = '__all__'
    success_url = reverse_lazy('autos:all')

But instead you did:

class AutoUpdate(LoginRequiredMixin, View):
    model = Auto
    fields = '__all__'
    success_url = reverse_lazy('autos:all')

(i.e. you extended View instead of UpdateView) - the result is that there is no def get(self, request): in your view. So you get the 405 HTTP status code (invalid method) when you navigate to the URL that forwards to the view.

References

• Autos CRUD Sample Code

• Installing Django Locally

• Using ngrok to turn in your assignments

• Embedding SVG in Markdown