Django formset is not getting saved - django

Question

I have a formset and I am trying to save it back. But, when I try to check if formset.is_valid() and save, validation always fails even if nothing in the formset has been changed. I am displaying already existing data using formset and trying to edit it. I don't know where I am going wrong. Can someone please help? :(
views.py
def product(request, product_id):
product = get_object_or_404(Product, pk=product_id)
productform = ProductForm(instance=product)
itemformset = modelformset_factory(Item, form = ItemForm, extra=0)
items = itemformset(queryset = Item.objects.filter(Product=product_id), prefix='items', )
if request.method == 'POST':
productform = ProductForm(request.POST, instance=product)
items = itemformset(request.POST, queryset = Item.objects.filter(Product=product_id), prefix='items', )
if productform.is_valid():
productform.save()
if items.is_valid():
items.save()
else:
print("fail")
context = {
'productform':productform,
'product_id': product_id,
'items':items,
}
return render(request, 'product.html', context )
.html
{% bootstrap_form productform %}
<div class="panel panel-default">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" data-parent="#accordion" href="#Items"> Items List </a>
</h4>
</div>
<div id="Items" class="panel-collapse collapse">
<table class="table table-bordered">
<thead>
<tr>
<th>Name</th>
<th>Tag</th>
</tr>
<thead>
<tbody>
{{ items.management_form }}
{% for form in items %}
<tr>
{{ form.id}}
<td> {{ form.Name }} </td>
<td> {{ form.Tag }} </td>
</tr>
{% endfor %}
</tbody>
</table>
</div>
</div>

Answer 1

You are rendering the form fields individually, but not displaying the errors. First, allow Django to render the forms and get the view working. Once you've done that, you can customise the template if required.
<tbody>
{{ items.management_form }}
{% for form in items %}
{{ form }}
{% endfor %}
</tbody>
See the docs on using formsets in templates rendering form fields manually for more information.
Doing it this way should allow you to see errors in the template. Another option is to print or log productform.errors and items.errors. Your current print("fail") tells you there is a problem, but not what the problem is.