CreateView that can return other Model data

Using Django Forms & APIs
1

Hi
I have this view, which is working fine but I want to display info from another Model (Books) on the top of the form in the same template.
What is the best way of doing it?

    model = Posts
    fields = ['title', 'content']

    def form_valid(self, form):
        form.instance.posted_by = self.request.user
        form.instance.bookid_id = self.kwargs['pk']
        form.save()
        return super().form_valid(form)```

```class Books(models.Model):
    sessaoid = models.ForeignKey(Sessoes, on_delete=models.CASCADE)
    book_name = models.CharField(max_length=100)
    author = models.CharField(max_length=50, default='Autor')
    description = models.CharField(max_length=250)
    sinopse = models.TextField()
    image = models.ImageField(upload_to='books/')
    presented_by = models.ForeignKey(User, on_delete=models.CASCADE)

    def __str__(self):
        return self.book_name

    def get_absolute_url(self):
        return reverse('book:detalhe_livro', kwargs={'pk': self.pk})

class Posts(models.Model):
    bookid = models.ForeignKey(Books, on_delete=models.CASCADE)
    title = models.CharField(max_length=100)
    content =models.TextField()
    date_posted = models.DateTimeField(default=timezone.now)
    posted_by = models.ForeignKey(User, on_delete=models.CASCADE)

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse('book:index')````

Thanks in advance
2

I’m guessing you’re using a CBV given you’re showing a form_valid method. If so, what you’re looking for is the get_context_data method to add additional data to the context to be rendered.

3

Hi Ken
Yes I am, the first line for some reason didn’t show up, here it is:

class PostsCreateView(CreateView):

I’ve tried that but I’m not getting any data or errors. I’m using a different Model on the get_context_data, could that be the reason?

4

Nope, absolutely not. You would use get_context_data to add any data to the context to be rendered.

Please show the complete view. We’re probably also going to need to see the template as well.

Side note: The three backticks (```) used to markup your code must be lines by themselves. They must not be the beginning or end of any of the code being fenced.

5

Ok, here is the view and the template

class PostsCreateView(CreateView):
    model = Posts
    fields = ['title', 'content']
    context_object_name = 'thebook'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context ['book'] = Books.objects.get(pk=self.kwargs['pk'])
        return context

    def form_valid(self, form):
        form.instance.posted_by = self.request.user
        form.instance.bookid_id = self.kwargs['pk']
        form.save()
        return super().form_valid(form)

and the template

{% extends "books/base.html" %}
{% load crispy_forms_tags %}

{% block content %}
    {% for b in thebookk %}
        <div>
            <h2>Este é o livro que está a comentar: {{ b.book_name }}</h2>
        </div>
    {% endfor %}

    <div class="content-section">
        <form method="POST">
            {% csrf_token %}
            <fieldset class="form-group">
                <legend class="border-bottom mb-4">Criar Post</legend>
                {{ form|crispy }}
            </fieldset>
            <div class="form-group">
                <button class="btn btn-outline-info" type="submit">Criar</button>
            </div>
        </form>
    </div>
{% endblock content%}
6

Two things.

  • The name of the object in the context is book, not thebookk.

  • You’re using the get method, which returns a single item, not an iterable. You can reference the fields directly from book.

Side note: CreateView is designed to render a blank form. There’s no value in defining context_object_name in this class - it’s never going to be used.

1 Like
7

You are, as always, absolutely right. I’ve made the changes and it’s working. Here they are.
Thank you very much Ken!

class PostsCreateView(CreateView):
    model = Posts
    fields = ['title', 'content']

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context ['book'] = Books.objects.get(pk=self.kwargs['pk'])
        return context

    def form_valid(self, form):
        form.instance.posted_by = self.request.user
        form.instance.bookid_id = self.kwargs['pk']
        form.save()
        return super().form_valid(form)
```

```
{% block content %}
        <div>
            <h2>Este é o livro que está a comentar: {{ book.book_name }}</h2>
        </div>

    <div class="content-section">
        <form method="POST">
            {% csrf_token %}
            <fieldset class="form-group">
                <legend class="border-bottom mb-4">Criar Post</legend>
                {{ form|crispy }}
            </fieldset>
            <div class="form-group">
                <button class="btn btn-outline-info" type="submit">Criar</button>
            </div>
        </form>
    </div>
{% endblock content%}
```