MDN LocalLibrary

Django walkthrough by the Mozilla Developer Network to create a simulated library interface web application

Hosted online through Heroku at https://pure-lowlands-01065.herokuapp.com

Learning points

def get_absolute_url(self):  
    """Returns the url to access a detail record for this book."""
    return reverse('book-detail', args=[str(self.id)])

Used in the template to refer to individual records i.e. used in a list view to go to a detailed view

In the template:

{% for book in book_list %}
    {{ book.get_absolute_url }}
{% endfor %}

django.views.generic

from django.views import generic

class AuthorListView(generic.ListView):
    # List view
    model = Author
    template_name = 'author_list.html'

class AuthorDetailView(generic.DetailView):
    # Detail view
    model = Author
    template_name = 'author_detail.html'
    # queryset = Author.objects.filter(first_name__contains='sun')

from django.views.generic.edit import CreateView, UpdateView, DeleteView
from django.contrib.auth.mixins import PermissionRequiredMixin

class AuthorCreateView(CreateView, PermissionRequiredMixin):
    model = Author
    fields = '__all__'
    permission_required = 'catalog.some_permission'
    template_name = 'author_form.html'

class AuthorUpdateView(UpdateView, PermissionRequiredMixin):
    model = Author
    fields = ['first_name', 'last_name', 'date_of_birth', 'date_of_death']
    permission_required = 'catalog.some_permission'
    template_name = 'author_form.html'

class AuthorDelete(DeleteView, PermissionRequiredMixin):
    model = Author
    success_url = reverse_lazy('authors')
    permission_required = 'catalog.can_mark_returned'
    template_name = 'author_confirm_delete.html'

Generic views from django.views that define common functionality such as lists and individual record details so you don't have to implement that

Within the generic views, can also change functionality such as queryset, template_name, pagination (paginate_by) and context_data

Following relationships 'backwards' (reverse lookup) with FOO_set.all where FOO is the source model name (model with the foreign key)

Reverse lookup can be done using _set on the table that has the foreign key, _set returns a QuerySet that can be used with all(), filter(), etc
```
# Blog has one-to-many relationship with Entry
b = Blog.objects.get(id=1)
b.entry_set.all() # Returns all Entry objects related to Blog
```

When updating request.session, if you are updating some information within session data, then Django willl not recognise that you've made a change to the session data, therefore you have to explicitly mark the session as having been modified

# Session object not directly modified, only data within the session. Session changes not saved!
request.session['my_car']['wheels'] = 'alloy'

# Set session as modified to force data updates/cookie to be saved.
request.session.modified = True

Limiting access to logged-in users

Can use @login_required decorator for function-based views, or LoginRequiredMixin for class-based views, which is passed as an argument to the class definition

UserPassesTest Mixin to restrict access to views to a certain group of users or on a certain condition. All you have to do is override test_func(self) to return a boolean

from django.contrib.auth.mixins import UserPassesTestMixin

class MyView(UserPassesTestMixin, View):

def test_func(self):
    return self.request.user.email.endswith('@example.com')

anthonysea/moz_locallibrary

MDN LocalLibrary

Learning points