6. Sessions framework - LiVanych/locallibrary GitHub Wiki

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Sessions were enabled automatically when we created the skeleton website.

The configuration is set up in the INSTALLED_APPS and MIDDLEWARE sections of the project file (locallibrary/locallibrary/settings.py), as shown below:

INSTALLED_APPS = [
    ...
    'django.contrib.sessions',
    ....

MIDDLEWARE = [
    ...
    'django.contrib.sessions.middleware.SessionMiddleware',
    ....

As a simple real-world example we'll update our library to tell the current user how many times they have visited the LocalLibrary home page.

Open /locallibrary/catalog/views.py, and make the changes shown below.

def index(request):
    ...

    num_authors = Author.objects.count()  # The 'all()' is implied by default.
    ... 
    # Number of visits to this view, as counted in the session variable.
    num_visits = request.session.get('num_visits', 0)
    request.session['num_visits'] = num_visits + 1

    context = {
        ...
        ...
        'num_visits': num_visits,
    }
    
    # Render the HTML template index.html with the data in the context variable.
    return render(request, 'index.html', context=context)

Add the line seen at the bottom of the following block to your main HTML template (/locallibrary/catalog/templates/index.html) at the bottom of the "Dynamic content" section to display the context variable:

<h2>Dynamic content</h2>

<p>The library has the following record counts:</p>
<ul>
  <li><strong>Books:</strong> {{ num_books }}</li>
  <li><strong>Copies:</strong> {{ num_instances }}</li>
  <li><strong>Copies available:</strong> {{ num_instances_available }}</li>
  <li><strong>Authors:</strong> {{ num_authors }}</li>
</ul>

<p>You have visited this page {{ num_visits }}
   {% if num_visits == 1 %} 
    time
   {% else %} 
    times
  {% endif %}.
</p>

Save your changes and restart the test server. Every time you refresh the page, the number should update.

That's All!

How to use sessions (Django docs)

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