Question

I’m currently trying to learn Django from the book and I read most of it and am now trying to write a webapp of my own. I just really can’t figure out how they all interact and how they aren’t fitting together.

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My urls.py file reads like this…

from django.conf.urls.defaults import patterns, include, url
from users.views import homepageview, submitted, referral_create

urlpatterns = patterns('',
(r'^$', homepageview),
(r'^submitted/$', referral_create),

the views.py file looks like this…

  # Create your views here.
from django.shortcuts import render_to_response
from django import forms
from datreferral.users.forms import ReferralCode

def homepageview(request):
    now = 'your damn referral code'
    return render_to_response('datreferraltemplate.html', {'now': now})

def referral_create(request):
    if request.method == 'POST':
        form = ReferralCode(request.POST)
        if form.is_valid():
            new_code = form.save()
            return HttpResponseRedirect(reverse(contact_details, args=(new_contact.pk,)))
    else:
        form = ReferralCode()

The form.py file looks like

from django import forms

class ReferralCode(forms.Form):
    referralcode = forms.CharField()

and the template looks like this…

{% extends "base.html" %}

{% block title %}
Enter your referral codes!
{% endblock %}

{% block content %}
<h1>Enter your code</h1>

    {% if errors %}
        <ul>
            {% for error in errors %}
            <li>{{ error }}</li>
            {% endfor %}
        </ul>
    {% endif %}

    <form action="" method="POST">
        <p>Subject: <input type="text" name="subject" value="{{ referralcode }}"></p>
        <input type="submit" value="Submit">
    </form>
{% endblock %}

Hopefully that’s enough info.

I am looking for two things. First off, when I try to view the page after submitting the form i get no where because I assume that the “if request.method == ‘POST’:” is not triggering. Obviously its something pretty obvious but I’m in one of those modes where I can find the bug for the life of me.

The second question I have is basically is plea for help. somehow after reading through those chapters multiple times I can’t seem to nail down how all of the pieces interact with each other. I know that the template and the urls.py and the views.py interact and I get (I think) but I can’t really grasp how the database and forms interact with each other and with the views/templates. like say I just wanted to a simple form where whatever the use inputted is written into the database… How would you do that? I’m using postgres if that matters.

Note: the form and the in the template is a modified version of code i found on here and tried to manipulate to meet my needs but failed so don’t be overly thrown off if that doesn’t make sense I wasn’t able to mess with that part that much yet because of these problems.

As I’m new to web development I really appreciate any one willing to help me or point me in the right direction.

Answer 1

1. You don’t return anything in you else clause. A views must always return a response, which can be pretty much anything, but in most cases you will return a instance of a (sub)-class of HttpResponse (I really like the render shortcut). It is a good idea to have a default return at the bottom of you view, add some early returns for “special” responses and otherwise let the execution reach the default return – this way you never have the case where you return nothing.

2. You have to use a Model to save data (have you work through the tutorial?). Usually the excution model is the following:

   1. you app gets a request and the urls.py is searched for a view that should be called
   2. the request is passed through the middleware
   3. you view is called and “does” something. I.e. it fetches data from the database (again using a model) or stores something in the db (or saves a uploaded file, sends a mail, etc. – aview can really do anything)
   4. you view returns “something”
   5. the returned “something” is passed through the middleware and will eventually be tranformed in a stream of data that is passed to the browser

Thats it. This is a bit simplified but it pretty much covers all important parts.