Django: Page not found (404) when posting form data - django

Question

I am trying to create a form to submit a blog post on an author detail page, so that the blog post will automatically use the current author as its "blog_author" foreign key. I'm aware that this approach isn't "secure" - it's a project site, and I'm trying to learn a new design pattern.
The Django docs recommended using 1 parent view and 2 subviews to handle get and post respectively (https://docs.djangoproject.com/en/3.0/topics/class-based-views/mixins/).
The page renders fine with the get, but the post gives me an error reading "Page not found (404) - no blog post found matching the query." The exception is raised by my parent view (blog.views.AuthorDetail), but there is no traceback.
Edit: Form should have been a ModelForm from the beginning
Here are my views:
class BlogAuthorDetailView(generic.DetailView):
model = BlogAuthor
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['form'] = BlogSubmitForm()
return context
class BlogSubmit(SingleObjectMixin, FormView):
template_name = 'blogauthor_detail.html'
form_class = BlogSubmitForm
model = BlogPost
def post(self, request, *args, **kwargs):
if not request.user.is_authenticated:
return HttpResponseForbidden()
self.object = self.get_object()
#Should I be overriding form_valid() to use the line above? Not sure if I'm doing my data
#handling in the right place
return super().post(request, *args, **kwargs)
def form_valid(self, form):
blogpost = form.save(commit=False)
blogpost.blog_author = self.object
blogpost.save()
return redirect('blog_author-detail', pk=self.object.id)
class AuthorDetail(View):
def get(self, request, *args, **kwargs):
view = BlogAuthorDetailView.as_view()
return view(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
view = BlogSubmit.as_view()
return view(request, *args, **kwargs)
URLs:
urlpatterns = [
path('', views.index, name='index'),
path('blogs/', views.BlogPostListView.as_view(), name='blogs'),
path('blog/<int:pk>', views.BlogPostDetailView.as_view(), name='blogpost-detail'),
path('bloggers/', views.BlogAuthorListView.as_view(), name='bloggers'),
path('blogger/<int:pk>', views.AuthorDetail.as_view(), name='blog_author-detail'),
path('blog/<int:pk>/create', views.BlogCommentCreate.as_view(), name='comment_create')
]
the template:
{% extends "base_generic.html" %}
{% block content %}
<h1>Title: {{ blogauthor.title }}</h1>
<p><strong>Author:</strong> {{ blogauthor }}</p>
<p><strong>Biography:</strong> {{ blogauthor.biography }}</p>
<p><strong>User:</strong> {{ blogauthor.user }}</p>
<p><strong>Posts:</strong>
{% for blog in blogauthor.blogpost_set.all %}
<p> {{ blog.title }} </p>
{% endfor %} </p>
<form action="" method="post">
{% csrf_token %}
<table>
{{ form.as_table }}
</table>
<input type="submit" value="Submit">
</form>
<div style="margin-left:20px;margin-top:20px">
<h4>Comments: Coming Soon!</h4>
{% endblock %}
Model:
class BlogPost(models.Model):
date_created = models.DateField(blank=False, default = date.today)
blog_author = models.ForeignKey('BlogAuthor', on_delete = models.SET_NULL, null=True)
title = models.TextField(max_length=70)
content = models.TextField(max_length=400, null=False)
class Meta:
ordering = ['date_created']
def get_absolute_url(self):
"""Returns the url to access a particular blog post instance."""
return reverse('blogpost-detail', args=[str(self.id)])
def __str__(self):
return self.title
And the forms.py:
class BlogSubmitForm(forms.Form):
title = forms.CharField()
content = forms.CharField(widget=forms.Textarea(attrs={'cols': 40, 'rows': 8}))
date_created = forms.DateField()
At this point, I suspect that the problem is related to my redirect() call in the form_valid override.
The things I have tried include:
Changing the form’s action from blank to the same URL as in my URL paths (possible I did this wrong)
Changing the code in form_valid() to read form.instance.blog_author = self.object (same exact error message, so I don’t think it’s this)
Fiddling with the form_valid()’s redirect call, including: using self.object instead or a URL, using a hardcoded url, getting rid of the second argument, and changing the 2nd arg to pk=, slug=.
Adding a get_success_url override (don’t really know why this would work)
edit: one of the excepted post calls that showed up in my local server went to blog/blogger/4, which is the url I want. Not sure what the issue is.

Answer 1

This is confusing on how you are using the template. Anyway, I think the simplest solution here is to get the BlogAuthor data from request.user and that is most logical, otherwise, anyone can post anything from another user as long as they can predict their primary key(which is a security hole). Here is how you can try:
from django.contrib.auth.mixins import LoginRequiredMixin
class BlogSubmit(LoginRequiredMixin, CreateView):
template_name = 'blogauthor_detail.html'
form_class = BlogSubmitForm
model = BlogPost
def get_success_url(self):
return reverse('blog_author-detail', pk=self.object.id)
def form_valid(self, form):
form.blog_author = self.request.user.blogauthor # assuming BlogAuthor has OneToOne relation with User
return super(BlogSubmit, self).form_valid(form)
Update
Purpose of FormView is to collect data from Forms, where CreateView is to store and create a new instance. Anyway, you need to change your code like this to make it work:
class BlogSubmit(LoginRequiredMixin, SingleObjectMixin, FormView):
template_name = 'blogauthor_detail.html'
form_class = BlogSubmitForm
model = BlogAuthor
def get_success_url(self):
return reverse('blog_author-detail', pk=self.object.id)
def form_valid(self, form):
self.object = self.get_object()
form.blog_author = self.object
form.save()
return super(BlogSubmit, self).form_valid(form)
Also update the form:
class BlogSubmitForm(forms.ModelForm):
class Meta:
model = BlogPost
fields = ['title', 'date_created', 'content']
FYI, to make SingleObjectMixin work, you need to change the model from BlogPost to BlogAuthor