Querying & Displaying Models

Now we have some blog posts in our database we can update our view and template to display them. Open blog/views.py and import our Post model at the top of the file:

from .models import Post

To load our posts from the database we execute a query on the Post.objects attribute. We want all posts so we use Post.objects.all(). We then want to pass the posts into our template so we update the dictionary passed into the render function:

def posts(request):
    posts = Post.objects.all()
    return render(request, "posts.html", {"name": "Alice", "posts": posts})

Inside blog/templates/posts.html, we wish to loop over all our posts and display the title and the body of the post. We can do this in a Django template using the {% for ... %} template tag which is terminated with {% endfor %}:

<body>
    <h1>Welcome to {{ name }}'s Blog!</h1>

    {% for post in posts %}
    <h2>{{ post.title }}</h2>
    <p>{{ post.body }}</p>
    {% endfor %}
</body>

For each post in our database, this for loop will generate a heading tag containing the post title and a paragraph tag (<p>) containing the body of the post. Save this and go back to your homepage and you should see the posts that you entered in the admin interface.

Challenges

  1. We are currently showing all posts, including those where public is set to false in the database. We can get only posts where public is true with:

    Post.objects.filter(public=True)

    Update the view function so only public posts are displayed on your homepage. Use the admin interface to make some posts private and confirm they are no longer visible.

  2. If the body of a post contains multiple lines, the line breaks will not be visible on our homepage because HTML is whitespace insensitive. Fix this by ensuring line break tags are inserted into our HTML by applying the linebreaks filter to our post.body:

    {{ post.body | linebreaks }}

  3. In your browser, right-click on the page and choose View Page Source to see the actual HTML generated by the template.