Django how to set a class based view queryset with function return

Question

im trying to make endless pagination with filtered data and im geting the data with get request.

views.py:

class ProductsView(ListView):
    
    paginate_by = 20
    context_object_name = 'products'
    template_name = "urunler.html"
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        renkler = Renk.objects.all()
        beden = Varyasyon.objects.all()
        katagori = Grub.objects.all()
        order = self.request.GET.get('order')
        filtered = Stok.objects.all().order_by('-urun_id__kayit_tarihi','foto').distinct('urun_id__kayit_tarihi','foto')
        checked_var = self.request.GET.getlist('varyasyon_id__in')
        checked_renk = self.request.GET.getlist('renk_id__in')
        checked_kat = self.request.GET.getlist('grub_id__in')
        if self.request.GET.getlist("varyasyon_id__in"):
            filtered = filtered.filter(
                Q(varyasyon_id__in = self.request.GET.getlist("varyasyon_id__in"))
            )
        if self.request.GET.getlist("renk_id__in"):
            filtered = filtered.filter(
                Q(renk_id__in = self.request.GET.getlist("renk_id__in"))
            )
        if self.request.GET.getlist("grub_id__in"):
            filtered = filtered.filter(
                Q(grub_id__in = self.request.GET.getlist("grub_id__in"))
            )
        
        if order == "date":
            filters = filtered.filter(
            Q(urun_id__yayin = True) & Q(stok_adet__gt = 0)
        )
        elif order == "sale":
            filters = filtered.filter(
            Q(urun_id__yayin = True) & Q(stok_adet__gt = 0) & Q(indirim = True)
        )
        elif order == "tesettur":
            filters = filtered.filter(
            Q(urun_id__yayin = True) & Q(stok_adet__gt = 0) & Q(urun_id__tesettur = True)
        )
        else:
            filters = filtered.filter(
            Q(urun_id__yayin = True) & Q(stok_adet__gt = 0)
        )
        
        context = {"renkler":renkler,"bedenler":beden,"katagoriler":katagori,'filtered':filters,'checkedvar':checked_var,'checkedrenk':checked_renk,'checkedkat':checked_kat}
        self.queryset = context
        return context
    queryset = get_context_data()

i want to set the queryset from get_context_data's return but it asks for self argument.

error

TypeError: ProductsView.get_context_data() missing 1 required positional argument: 'self'

when i define queryset on the top it says that get_context_data is not defined.

Answer 1

try to override get_queryset() like this and then override your context using get_context_data i tried it and it worked for me.

class ProductsView(ListView):
paginate_by = 12
context_object_name = 'filtered'
template_name = 'urunler.html'

def get_queryset(self):
    order = self.request.GET.get('order')
    filtered = Stok.objects.all().order_by('-urun_id__kayit_tarihi','foto').distinct('urun_id__kayit_tarihi','foto')
    checked_var = self.request.GET.getlist('varyasyon_id__in')
    checked_renk = self.request.GET.getlist('renk_id__in')
    checked_kat = self.request.GET.getlist('grub_id__in')
    if self.request.GET.getlist("varyasyon_id__in"):
        filtered = filtered.filter(
            Q(varyasyon_id__in = self.request.GET.getlist("varyasyon_id__in"))
        )
    if self.request.GET.getlist("renk_id__in"):
        filtered = filtered.filter(
            Q(renk_id__in = self.request.GET.getlist("renk_id__in"))
        )
    if self.request.GET.getlist("grub_id__in"):
        filtered = filtered.filter(
            Q(grub_id__in = self.request.GET.getlist("grub_id__in"))
        )
    
    if order == "date":
        filters = filtered.filter(
        Q(urun_id__yayin = True) & Q(stok_adet__gt = 0)
    )
    elif order == "sale":
        filters = filtered.filter(
        Q(urun_id__yayin = True) & Q(stok_adet__gt = 0) & Q(indirim = True)
    )
    elif order == "tesettur":
        filters = filtered.filter(
        Q(urun_id__yayin = True) & Q(stok_adet__gt = 0) & Q(urun_id__tesettur = True)
    )
    else:
        filters = filtered.filter(
        Q(urun_id__yayin = True) & Q(stok_adet__gt = 0)
    )
    return filters

def get_context_data(self, **kwargs):
    context = super().get_context_data(**kwargs)

    renkler = Renk.objects.all()
    beden = Varyasyon.objects.all()
    katagori = Grub.objects.all()
    order = self.request.GET.get('order')
    
    filtered = Stok.objects.all().order_by('-urun_id__kayit_tarihi','foto').distinct('urun_id__kayit_tarihi','foto')
    checked_var = self.request.GET.getlist('varyasyon_id__in')
    checked_renk = self.request.GET.getlist('renk_id__in')
    checked_kat = self.request.GET.getlist('grub_id__in')
    if self.request.GET.getlist("varyasyon_id__in"):
        filtered = filtered.filter(
            Q(varyasyon_id__in = self.request.GET.getlist("varyasyon_id__in"))
        )
    if self.request.GET.getlist("renk_id__in"):
        filtered = filtered.filter(
            Q(renk_id__in = self.request.GET.getlist("renk_id__in"))
        )
    if self.request.GET.getlist("grub_id__in"):
        filtered = filtered.filter(
            Q(grub_id__in = self.request.GET.getlist("grub_id__in"))
        )

    
    if order == "date":
        filters = filtered.filter(
        Q(urun_id__yayin = True) & Q(stok_adet__gt = 0)
    )
    elif order == "sale":
        filters = filtered.filter(
        Q(urun_id__yayin = True) & Q(stok_adet__gt = 0) & Q(indirim = True)
    )
    elif order == "tesettur":
        filters = filtered.filter(
        Q(urun_id__yayin = True) & Q(stok_adet__gt = 0) & Q(urun_id__tesettur = True)
    )
    else:
        filters = filtered.filter(
        Q(urun_id__yayin = True) & Q(stok_adet__gt = 0)
    )
    context.update({"renkler":renkler,"bedenler":beden,"katagoriler":katagori,'checkedvar':checked_var,'checkedrenk':checked_renk,'checkedkat':checked_kat})
    return context

Answer 2

Maybe you should override get_queryset method. A queryset is not a context dict:

class ProductsView(ListView):

    paginate_by = 20
    context_object_name = 'products'
    template_name = "urunler.html"

    def get_queryset(self):
        queryset = super().get_queryset()

        # do stuff here to change queryset dynamically
        ...

        return queryset

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)

        # do stuff here to update your context dict
        ...

        return context

Answer 3

First - why your code fails. You override get_context_data , then make invalid call to it (you don't pass self to it at all), and finally all this happens during class creation, not instantiation, so get_context_data isn't aware about request when you call it on last line. And context_data is not same thing as queryset . Here's what you can do instead to get paginated content of filtered queryset:

class ProductsView(ListView):
    paginate_by = 20
    context_object_name = 'filtered'
    template_name = 'urunler.html'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context.update({
            'renkler': Renk.objects.all(),
            'bedenler': Varyasyon.objects.all(),
            'katagoriler': Grub.objects.all(),
            'checkedvar':  self.request.GET.getlist('varyasyon_id__in'),
            'checkedrenk': self.request.GET.getlist('renk_id__in'),
            'checkedkat': self.request.GET.getlist('grub_id__in'),
        })
        return context

    def get_queryset(self):
        filtered = Stok.objects.all().order_by('-urun_id__kayit_tarihi','foto').distinct('urun_id__kayit_tarihi','foto')
        
        checked_var = self.request.GET.getlist('varyasyon_id__in')
        checked_renk = self.request.GET.getlist('renk_id__in')
        checked_kat = self.request.GET.getlist('grub_id__in')
        if checked_var:
            filtered = filtered.filter(varyasyon_id__in=checked_var)
        if checked_renk:
            filtered = filtered.filter(renk_id__in=checked_renk)
        if checked_cat:
            filtered = filtered.filter(grub_id__in=checked_cat)
        
        filtered = filtered.filter(urun_id__yayin=True, stok_adet__gt=0)
        order = self.request.GET.get('order')
        if order == "sale":
            filtered = filtered.filter(indirim=True)
        elif order == "tesettur":
            filtered = filtered.filter(urun_id__tesettur=True)
        
        return filtered