Django - ModelForm - UpdateView -pk - django

Question

I would like to implement UpdateView in order to update selected objects of my Model.
Currently I have:
views.py
def fd_detail(request, fdslug):
fddetail = Fd.objects.get(slug=fdslug)
cffilter = CashFlowFilter(request.GET, queryset=CashFlow.objects.filter(feeder__slug=fdslug))
return render(request, 'fd/fd_detail.html',
{'fddetail': fddetail,
'cffilter': cffilter,
})
class CashFlowUpdate(UpdateView):
model = CashFlow
fields = ['amount', 'description']
url.py
path('<slug:fdslug>/updatecashflow/', views.CashFlowUpdate.as_view(),name = "update_cashflow"),
path('<slug:fdslug>/', views.fd_detail, name="fd_detail")
update_cashflow.html
<form method="post">
{% csrf_token %}
{{ form.as_p }}
<input type="submit" value="Update">
</form>
I get the following error : " Generic detail view CashFlowUpdate must be called with either an object pk or a slug in the URLconf." , which means i need to pass-through the primary key of the object I want to Update... What is the best way to do it? Currently all my objects are displayed via a table (see below)? i could add a column with a url link "Edit", but how to put the pk in it?
<table class="table table-bordered">
<thead>
<tr>
<th>Amount</th>
<th>Description</th>
<th>Edit</th>
</tr>
</thead>
<tbody>
{% for cashflow in cffilter.qs %}
<tr>
<td> {{cashflow.amount}} </td>
<td> {{cashflow.description}} </td>
<td> ?????? </td>
</tr>
{% empty %}
<tr>
<td colspan="5"> No cashflow matches your search criteria</td>
</tr>
{% endfor %}
</tbody>
</table>
many thanks

Answer 1

Like the error says:
Generic detail view CashFlowUpdate must be called with either an object pk or a slug in the URLconf.
An update view usually needs some kind of URL parameter to determine which object to update. It implicitly aims to check for two fields: the slug and the primary key. But here in your urls.py, you used fdslug as a URL parameter.
This can easily be resolved by specifying a slug_url_kwarg [Django-doc] yourself, like:
class CashFlowUpdate(UpdateView):
model = CashFlow
fields = ['amount', 'description']
slug_url_kwarg = 'fdslug'
As for an edit link, you can add a {% url ... %} template tag, like:
<td>edit</td>