rodney.py

from django.db import models

class ProcessorMake(models.Model):
    name = models.CharField(max_length=20)

    def __unicode__(self):
        return self.name

class ProcessorLine(models.Model):
    processormake = models.ForeignKey(ProcessorMake)
    name = models.CharField(max_length=20)

    def __unicode__(self):
        return self.name

class ProcessorModel(models.Model):
    processormodel = models.ForeignKey(ProcessorLine)
    name = models.CharField(max_length=20)

    def __unicode__(self):
        return self.name

initial_data.yaml

- model: paq.ProcessorMake
    pk: 1
    fields:
        name: AMD
- model: paq.ProcessorMake
    pk: 2
    fields:
        name: Intel

- model: paq.ProcessorLine
pk: 1
fields:
processormake: 1
name: FX
- model: paq.ProcessorLine
pk: 2
fields:
processormake: 1
name: A-Series
- model: paq.ProcessorLine
pk: 3
fields:
processormake: 1
name: Phenom II
- model: paq.ProcessorLine
pk: 4
fields:
processormake: 1
name: Athlon II
- model: paq.ProcessorLine
pk: 5
fields:
processormake: 1
name: Sempron


views.py

from django.shortcuts import render
from models import ProcessorMake, ProcessorLine, ProcessorModel
from forms import ProcessorMakeForm, ProcessorLineForm, ProcessorModelForm

def chooseprocessor(request):
    make = request.session.get('make', None)
    line = request.session.get('line', None)
    model = request.session.get('model', None)
    if 'make' in request.session and 'line' in request.session and 'model' in request.session:
        pass

    if 'make' in request.session and 'line' in request.session:
        make=ProcessorMake.objects.get(id=reques­t.session['make'])
        line=ProcessorLine.objects.get(id=reques­t.session['line'])

    if request.method == 'GET':
        pass

    elif request.method == 'POST':
        pass

    # User chose Make just now or sometime in the past
    if 'make' in request.session:
        make=ProcessorMake.objects.get(id=reques­t.session['make'])

    # User left and came back
    if request.method == 'GET':
        form = ProcessorLineForm()
        form.fields["name"]=ProcessorL­ine.objects.filter(processormake__id=mak­e.pk)
        return render(request, 'chooseprocessorline.html', { 'form': form, 'make': make.name })

    # User just chose Line on the previous screen
    elif request.method == 'POST':
        form = ProcessorLineForm(request.POST)
    if form.is_valid():
        line=ProcessorLine.objects.get(name=form­.cleaned_data['name'])
        request.session['line']=line.pk
        form = ProcessorModelForm()
        form.fields["name"]=ProcessorM­odel.objects.filter(processorline__id=li­ne.pk)

        return render(request, 'chooseprocessormodel.html', { 'form': form, 'make': make.name, 'line': line.name })
    else:
        return render(request, 'chooseprocessorline.html', { 'form': form, 'make': make.name })


    # User either newly here or cookies were deleted
    if request.method == 'GET':
        form = ProcessorMakeForm()

        return render(request, 'chooseprocessormake.html', { 'form': form, })

    if request.method == 'POST': # User just chose Make
        form = ProcessorMakeForm(request.POST)
    if form.is_valid():
        make=ProcessorMake.objects.get(name=form­.cleaned_data['name'])
        request.session['make']=make.pk
        form = ProcessorLineForm()
        form.fields["name"]=ProcessorL­ine.objects.filter(processormake__id=mak­e.pk)

        return render(request, 'chooseprocessorline.html', { 'form': form, 'make': make.name })

    return render(request, 'chooseprocessormake.html', { 'form': form, })

def chooseprocessorbak(request):
    if request.method == 'POST':
        form = ProcessorMakeForm(request.POST)
    if form.is_valid():
        primarykey=ProcessorMake.objects.get(nam­e=form.cleaned_data['name'])
        request.session['make']=primarykey
        request.session['started']=True

        return render(request, 'paqsuccess.html', { 'form': form.cleaned_data, 'primarykey': primarykey.pk })
    else:
        form = ProcessorMakeForm()

        return render(request, 'paq.html', { 'form': form, })