Passing data back to Django view - django

Question

Inside of a table in my template I have the following which works great:
<tbody>
{% for item in items %}
<tr>
<td>{{ item.id }}</td>
<td>{{ item.name }}</td>
<td>{{ item.status }}</td>
<td>{{ item.start_time }}</td>
<td>{{ item.end_time }}</td>
</tr>
</tbody>
I would like to add a form that posts the items to a view. I've tried this:
<form align="center" action="{% url 'app:doit' %}" method="post" ><b></b>
{% csrf_token %}
<input type="hidden" name="items" value="{{ items}}" />
<input type="submit" name="export" value="Export" >
</form>
but that doesn't work as I expected it would. The data comes into the view as a sequence of characters, something like this, ",..." How do I pass {{items}} back to a view so I can process the items as python objects?
The export method in my view contains this:
if 'items' in request.POST:
my_items = request.POST['items']

Answer 1

You cannot POST a QuerSet back to a view. HTML form cannot understand a Django QuerySet. That would be nice, though!
What you can do is to create a custom template tag that would generate this:
<input type="hidden" name="items" value="{% my_items items %}" />
to this:
<input type="hidden" name="items" value="1,2,5,7,8" />
where these numbers are the id of each item. You can also use the name field if you like, since it's not very secure to expose the ids.
Then, once POSTed, inside the view I would do:
if 'items' in request.POST:
# my_item_values is a str
my_item_values = request.POST['items']
try:
my_item_values = my_item_values.split(',')
except TypeError:
# Handle error of conversion from string to list here
else:
# typecast succedded. Get your items!
items = Item.objects.filter(id__in=my_item_values) # This is a QuerySet
# or this (if you used the names)
items = Item.objects.filter(name__in=my_item_values) # This is a QuerySet
The custom template tag would look like this:
#register.simple_tag()
def my_items(items):
return ','.join([item.name for item in items])