create invoice part 2 view

viewsxx.py

@login_required
def createBuildInvoice(request, slug):
    #fetch that invoice
    try:
        invoice = Invoice.objects.get(slug=slug)
        pass
    except:
        messages.error(request, 'Something went wrong')
        return redirect('invoices')

    #fetch all the products - related to this invoice
    products = Product.objects.filter(invoice=invoice)


    context = {}
    context['invoice'] = invoice
    context['products'] = products

    if request.method == 'GET':
        prod_form  = ProductForm()
        inv_form = InvoiceForm(instance=invoice)
        client_form = ClientSelectForm(initial_client=invoice.client)
        context['prod_form'] = prod_form
        context['inv_form'] = inv_form
        context['client_form'] = client_form
        return render(request, 'invoice/create-invoice.html', context)

    if request.method == 'POST':
        prod_form  = ProductForm(request.POST)
        inv_form = InvoiceForm(request.POST, instance=invoice)
        client_form = ClientSelectForm(request.POST, initial_client=invoice.client, instance=invoice)

        if prod_form.is_valid():
            obj = prod_form.save(commit=False)
            obj.invoice = invoice
            obj.save()

            messages.success(request, "Invoice product added succesfully")
            return redirect('create-build-invoice', slug=slug)
        elif inv_form.is_valid and 'paymentTerms' in request.POST:
            inv_form.save()

            messages.success(request, "Invoice updated succesfully")
            return redirect('create-build-invoice', slug=slug)
        elif client_form.is_valid() and 'client' in request.POST:

            client_form.save()
            messages.success(request, "Client added to invoice succesfully")
            return redirect('create-build-invoice', slug=slug)
        else:
            context['prod_form'] = prod_form
            context['inv_form'] = inv_form
            context['client_form'] = client_form
            messages.error(request,"Problem processing your request")
            return render(request, 'invoice/create-invoice.html', context)


    return render(request, 'invoice/create-invoice.html', context)