How can I take the choice in drop-down list and redirect to another page?

Using Django
1

I’m currently just learning Django and I’m doing electronic grade book. I have tried everything, have read all the documentation, but nothing helps. It seems I miss a simple logic somewhere. I need to make two pages:

The first one “teacher_interface” is a simple inteface for the teacher with just one drop-down list, teacher chooses the necessary class (i.e 1C, 2B, 4C) and the button “Students”, which should somehow take the chosen class from drop-down list input and redirect to the second page “class_students”.

The second “class_students” is alike the “teacher_interface”, but with the table of students of the chosen class.

I have the One-to-many relation between classes Student and Class:

Firstly, I tried redirecting from “teacher_interface” to “class_students”, using in template:

{% url "name" %}

Parts of code: 1) models.py dpaste/eqxm (Python) 2) urls.py dpaste/eUEO (Python) 3) views.py dpaste/ap8D (Python) 4) template teacher_interface.html dpaste/v4m9 (HTML + Django/Jinja) 5) template class_students.html dpaste/0gXK (HTML + Django/Jinja)

But it shows me: Reverse for ‘class_students’ with no arguments not found. 1 pattern(s) tried: [‘school/teacher/(?P<class_id>[0-9]+)/class/$’]

I tried everything, but nothing helped, this and the similar: Django - getting Error “Reverse for ‘detail’ with no arguments not found. 1 pattern(s) tried:” when using {% url “music:fav” %} I understood maybe this two options of redirect will not work in my case:

{% url 'class_students' class.id %}

{% url 'class_students' class_id %}

I also don’t know if it’s possible to do on the same page.

So I decided to redirect using redirect from django.shortcuts. I changed my teacher_interface view, so that it took the id of the chosen by the teacher class if request method is POST and redirected. I also made this change in my template “teacher_interface.html”:

from

action="{% url 'class_students' %}"

to

action=""

Changed view:

def teacher_interface(request):
class_queryset = Class.objects.order_by("class_number", "group")
class_id = None
if request.method == "POST":
    class_id = Class.objects.get("id")
    return redirect("class_students", class_id)
context = {
    "class_queryset": class_queryset,
    "class_id": class_id,
}
return render(request, "teacher_interface.html", context)

But when I choose the class and click the “Students” button, it shows me: Cannot resolve keyword ‘i’ into field. Choices are: class_number, curriculum, discipline, group, id, student, task, type_of_class, type_of_class_id. Id is certainly is a key, but it tries to resolve only “i”.

I tried/read everything here, but nothing works.

I even wrote the default like this:

class_id = Class.objects.get("id", "default")

I am sure I just don’t understand properly how to get teacher’s choice, pass it to another or the same function and redirect, saving this information. I will be really grateful for you help, even if you just advise what I can read to figure it out.

2

If you need further assistance, please post your relevant code here. The links you included in your post appear like they will expire in about a week, doing no good for those coming along later.

You probably want to do this using a Form. (See Working with Forms).
Yes, this form will have one field, the ChoiceField, and a Submit button with the label “Students”.
Your POST method will then validate the form, and allow you to redirect to the right page. (See The view.)

3

Thanks a lot, I think I managed finally to find the an answer even without using forms, but I will definitely try doing like on this link soon!