Django : HTML form action directing to view (or url?) with 2 arguments

Question

Started learning django about a week ago and ran into a wall. Would really appreciate any enlightenment...

models.py

class data(models.Model):
    course = models.CharField(max_length = 250)

    def __str__(self):
        return self.course

html

Converted the objects in models.course to schlist

<link rel="stylesheet" type="text/css" href="{% static '/chosen/chosen.css' %}" />
<form action={% views.process %}  method="GET">
      <div>
        <h4 style="font-family:verdana;">First Course: </h4>
        <select data-placeholder="Course" style="width:350px;" class="chosen-select" tabindex="7">
          <option value=""></option>
          {% for item in schlist %}
          <option> {{ item }} </option>
          {% endfor %}
        </select>
      </div>
      </br>
      <div>
        <h4 style="font-family:verdana;">Second Course:</h4>
        <select data-placeholder="Course" style="width:350px;" class="chosen-select" tabindex="7">
          <option value=""></option>
          {% for item in schlist %}
          <option> {{ item }} </option>
          {% endfor %}
        </select>
      </div>
      </br>
  <input type="submit" value="Compare!" />
</form>

urls.py (having my doubts if this works..)

urlpatterns = [
    url(r'^(\d+)/(\d+)$',views.process, name = 'process'),
]

view.py

def process(request,q1 ,q2):
    obj1= get_object_or_404(Schdata, course = q1)
    obj2= get_object_or_404(Schdata, course = q2)
 ........

Was wondering if it is possible for the form action to direct the action to

(1) view.py or (2) url.py (and eventually to a view.py) with 2 arguments selected?

If so how should the form action be? {{view ?}} or {{url ?}}. Am I missing out the definition of my arguments in my HTML?

Directing to views.py:

User input is CharField, could use get_object_or_404 to get the model pk. However when defining my urls.py I would get a Noreverse error as my url arguments is the primary key.

Directing to urls.py:

Url arguments is primary key. From the way I see it, I need to magically convert my User input Charfield to a pk before passing it to urls.py

Is there a (or) function for get() in django? E.g get_object_or_404(pk = q1 or course = q1)?

Would really appreciate any advice. Been staring at this for hours.

Did you find a suitable solution for the above problem yet? – Abijith Mg Mar 05 '17 at 03:54 — Abijith Mg, Mar 05 '17 at 03:54

score 32 · Accepted Answer · answered Feb 24 '17 at 14:27

You are trying to use the reverse resolution of urls in Django.

In your html file correct form action url to the following and method should be POST:

<form action={% url 'process' %}  method="POST">

In case you are trying to pass parameters along then use this:

<form action={% url 'process' request.user.id 4 %}  method="POST">

Reference: https://docs.djangoproject.com/en/1.10/topics/http/urls/

score 13 · Answer 2 · answered Feb 19 '20 at 06:37

Yes i'm late but it can help others for better understanding how Django processes the request.

Django 3.0 pattern

How Django processes the request

Basic :

First Django check the matching URL.
If URL is matched then calling the defined view to process the request. (Success)
If URL not matched/found the Django invokes error Page Not Found

In detail reading :

Official Django Documentations How Django processes a request

These are your URL patterns :

urlpatterns = [ path('profile/edit/<int:pk>/',views.editprofile, name='editprofile'),]

Third argument in urlpatterns is for if you want to change the url pattern from current to this :

urlpatterns = [ url('profile/edit/user/id/<int:pk>',views.editprofile, name = 'editprofile'),]

You don't need to redefine url pattern in all Templates where you using url name.

For Example :

This is my template profile.html where i used the url name instead of hard coded url.

<a class="item" href="{% url 'editprofile' user.id %}" >Edit profile </a>

Solution of your problem :

.html

Only use url name instead of hard coded url in your templates and pass arguments.

<form action={% process no_of_arguments  %}  method="POST">

views.py

Here you can process your request

def process(request,no_of_arguments):

Become good django developer

You can also use Django ModelForms for your model. Using model forms or simple form you can do multiple things

Modular approach
Write server side validation in related form instead of doing in views.py
Readable code - Clean code

Django : HTML form action directing to view (or url?) with 2 arguments

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