Django的/没有反向匹配

Question

I'm trying to make a picture the url to the post the picture represents, and I must be doing something wrong, but I don't know what.

I am getting this error when trying to visit the home page of my site.

Error during template rendering

In template .../home.html, error at line 48

Reverse for 'view_post' with keyword arguments '{'post_id': ''}' not found. 1 pattern(s) tried: ['post/(?P[0-9]+)/$']

and the code it showcases

<a href="{% url 'view_post' post_id=post.post_id %}"><img src="media/{{ item.image }}"></a>

Also this is my view

def view_post(request, post_id):
    post = get_object_or_404(Post,id=post_id)
    return render(request,'gram/view_post.html',{'post': post})

And url

url(r'^post/(?P<post_id>[0-9]+)/$', views.view_post, name='view_post'),

Thank you for your help.

Answer 1

I make some assumptions based on your code examples. This line:

post = get_object_or_404(Post,id=post_id)

says that the class Post has a property id . However in your template you call post.post_id . Assuming that post is an object instance of the class Post , it should have the property id . Probably there is no such property like post_id in the class Post .

This means that in the template post.post_id won't return an output. Your urls, which are not shown here, expect an integer ['post/(?P[0-9]+)/$'] . Therefore the error is thrown.

Try this snippet:

{% url 'view_post' post_id=post.id %}

and check what happens.

As I said, this is based on some presumptions and I don't guarantee success.

Answer 2

Turned out I'm just stupid and made it hard for myself. The problem was I've done <a href in my home.html and home view didn't know what post.id is - obviously. The problem is fixed.