We have different pieces in place: the Post model is defined in models.py, we have post_list in views.py and the template added. But how will we actually make our posts appear in our HTML template? Because that is what we want: take some content (models saved in the database) and display it nicely in our template, right?
This is exactly what views are supposed to do: connect models and templates. In our post_list view we will need to take models we want to display and pass them to the template. So basically in a view we decide what (model) will be displayed in a template.
OK, so how will we achieve it?
We need to open our blog/views.py. So far post_list view looks like this:
from django.shortcuts import render
def post_list(request):
return render(request, 'blog/post_list.html', {})
Remember when we talked about including code written in different files? Now it is the moment when we have to include the model we have written in models.py. We will add this line from .models import Post like this:
from django.shortcuts import render
from .models import Post
Dot after from means current directory or current application. Since views.py and models.py are in the same directory we can simply use . and the name of the file (without .py). Then we import the name of the model (Post).
But what's next? To take actual blog posts from Post model we need something called QuerySet.
You should already be familiar with how QuerySets work. We talked about it in Django ORM (QuerySets) chapter.
So now we are interested in a list of blog posts that are published and sorted by published_date, right? We already did that in QuerySets chapter!
Post.objects.filter(published_date__isnull=False).order_by('published_date')
Now we put this piece of code inside the post_list file, by adding it to the function def post_list(request):
from django.shortcuts import render
from .models import Post
def post_list(request):
posts = Post.objects.filter(published_date__isnull=False).order_by('published_date')
return render(request, 'blog/post_list.html', {})
Please note that we create a variable for our QuerySet: posts. Treat this as the name of our QuerySet. From now on we can refer to it by this name.
The last missing part is passing the posts QuerySet to the template (we will cover how to display it in a next chapter).
In the render function we already have parameter with request (so everything we receive from the user via the Internet) and a template file 'blog/post_list.html'. The last parameter, which looks like this: {} is a place in which we can add some things for the template to use. We need to give them names (we will stick to 'posts' right now :)). It should look like this: {'posts': posts}. Please note that the part before : is wrapped with quotes ''.
So finally our blog/views.py file should look like this:
from django.shortcuts import render
from .models import Post
def post_list(request):
posts = Post.objects.filter(published_date__isnull=False).order_by('published_date')
return render(request, 'blog/post_list.html', {'posts': posts})
That's it! Time to go back to our template and display this QuerySet!
If you want to read a little bit more about QuerySets in Django you should look here: https://docs.djangoproject.com/en/1.6/ref/models/querysets/