django forms and filtering

So i have this jobs select form that should allow a user to:

1) select a filterBy set of radio buttons. This lets the user select which method he wants to filter a list by. (this will perform a GET with a 'filterBy' query string

2) allow a user to filter the list by an object from a comobox that is the result of #1. This form performs a POST with the 'filter' set to the pk of a filterBy object

Here is the code i have:

selectForm = JobSelectForm()
filterByForm = FilterByForm()
filterForm = FilterForm()

if request.method == 'POST':
    #this works just fine
    if 'job' in request.POST:
        return HttpResponseRedirect("/portal/jobs/%s/"%(request.POST['job']))

    if 'filter' in request.POST:
        filterForm = FilterForm(initial = {'filter': request.POST['filter']})

        ###### The Problem is below here
        ###### I cant get the 'filterBy' query string 
        ###### because this is a POST and not a GET
        ###### Is there a better way to write this filtering?

        if request.GET['filterby'] == 'G':
            obj = Group.objects.get(pk=request.POST['filter'])
            selectForm.fields['job'].queryset = Job.objects.filter(group=obj).order_by('name')
        elif request.GET['filterby'] == 'H':
            obj = Host.objects.get(pk=request.POST['filter'])
            selectForm.fields['job'].queryset = Job.objects.filter(host=obj).order_by('name')
        elif request.GET['filterby'] == 'L':
            obj = Location.objects.get(pk=request.POST['filter'])
            selectForm.fields['job'].queryset = Job.objects.filter(colo=obj).order_by('name')

###### All of this works fine too
eli开发者_开发百科f request.method == 'GET':
    if request.GET.has_key('filterby'):
        if request.GET['filterby']:
            filterByForm = FilterByForm(initial = {'filterby': request.GET['filterby']})
            if request.GET['filterby'] == 'G':
                filterForm.fields['filter'].queryset = Group.objects.all().order_by('name')
            elif request.GET['filterby'] == 'H':
                filterForm.fields['filter'].queryset = Host.objects.all().order_by('name')
            elif request.GET['filterby'] == 'L':
                filterForm.fields['filter'].queryset = Location.objects.all().order_by('name')

Use request.REQUEST (see: Django Request and Response Objects). It holds the values of both request.POST and request.GET.

Also, when using dictionaries in Python, you should always verify that the key you're trying to access exists. This can be done in one of two ways:

1) Explicitly test for key in dictionary

if request.GET.has_key('filterby') and request.GET['filterby'] == 'G':
    obj = Group.objects.get(pk=request.POST['filter'])
    selectForm.fields['job'].queryset = Job.objects.filter(group=obj).order_by('name')

2) Use the dictionary's get method

if request.GET.get('filterby') == 'G':
    obj = Group.objects.get(pk=request.POST['filter'])
    selectForm.fields['job'].queryset = Job.objects.filter(group=obj).order_by('name')

With dict.get you can also pass a default value:

if request.GET.get('filterby', valueIfKeyDoesntExist) == 'G':
    obj = Group.objects.get(pk=request.POST['filter'])
    selectForm.fields['job'].queryset = Job.objects.filter(group=obj).order_by('name')

You should place your problematic code in form's overrided __init__ method.