Django 'QuerySet' object has no attribute 'split' using modelform

Question

I'm having a problem getting my view to update a manytomany field. It returns this after the form is submitted.

Traceback:
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
  111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/home/footbook/Ubuntu One/webapps/fb/poc/../poc/activity/views.py" in activity_save_page
  44.             group_names = form.cleaned_data['groups'].split()

Exception Type: AttributeError at /activity_save/
Exception Value: 'QuerySet' object has no attribute 'split'

Here are the files. Models.py

class Group (models.Model):
    group_nm = models.CharField(max_length=64)
    group_desc = models.CharField(max_length=250)
    created = models.DateTimeField(auto_now_add=True)
    active_yn = models.BooleanField(default=True)
    def __unicode__(self):
        return self.group_nm



class Activity(models.Model):
    activity_nm = models.CharField(max_length=60)  
    activity_desc = models.CharField(max_length=250)
    startdt = models.DateField()
    enddt = models.DateField()
    crdt = models.DateTimeField(auto_now_add=True,editable=False)
    groups =  models.ManyToManyField(Group)
    upddt = models.DateTimeField(editable=False)
    def  save(self, *args, **kwargs):
        if not self.id:
            self.crdt = datetime.date.today()
        self.upddt = datetime.datetime.today()
        super(Activity, self).save(*args, **kwargs)
    def __unicode__(self):
        return self.name     

forms.py

def make_custom_datefield(f):
    formfield = f.formfield()
    if isinstance(f, models.DateField):
        formfield.widget.format = '%m/%d/%Y'
        formfield.widget.attrs.update({'class':'datePicker', 'readonly':'true'})
    return formfield


class ActivitySaveForm(forms.ModelForm):
    formfield_callback = make_custom_datefield
    def __init__(self, *args, **kwargs):
        super(ActivitySaveForm, self).__init__(*args, **kwargs)
        self.fields['activity_nm'].label = "Activity Name"
        self.fields['activity_desc'].label = "Describe It"
        self.fields['startdt'].label = "Start Date"
        self.fields['enddt'].label = "End Date"
        self.fields['groups'].label ="Group"
    class Meta:
        model = Activity

views.py

def activity_save_page(request):
    if request.method == 'POST':
        form = ActivitySaveForm(request.POST)
        if form.is_valid():
            act, created = Activity.objects.get_or_create(
                activity_nm = form.cleaned_data['activity_nm']
            )
            act.activity_desc = form.cleaned_data['activity_desc']
            if not created:
                act.group_set.clear()
            group_names = form.cleaned_data['groups'].split()
            for group_name in group_names:
                group, dummy = Group.objects.get_or_create(group_nm=group_name)
                act.group_set.add(group)
            act.save()
            return HttpResponseRedirect('/activity/')
    else:
        form = ActivitySaveForm()
    variables = RequestContext(request, {
        'form': form
    })
    return render_to_response('activity_save.html', variables)

I think it would work if I wasn't using the modelform, but I need it to implement this datepicker. Since it's a manytomany field, I want to split them when they are entered into the database, but my queryset fails. I've tried changing this a bunch of different ways, but I'm stuck. I've seen a lot of similar questions, but they either had foreign keys or no modelform.

Thanks.

EDIT: activity_save.html

{% extends "base.html" %}
{% block title %}Save Activity{% endblock %}
{% block head %}Save Activty{% endblock %}
<input class="datePicker" readonly="true" type="text" id="id_startdt" />
<input class="datePicker" readonly="true" type="text" id="id_enddt" />
{% block content %}


<form action="{% url activity.views.activity_save_page act_id%}" method="post">{% csrf_token %}

{{ form.as_p }} 

<input type="submit" value="save it" />
</form>
{% endblock %}

Answer 1

Exactly as the error describes: a QuerySet does not have a split method. You cannot call my_qs.split().

form.cleaned_data['groups'] returns cleaned data; it has already taken care of the form string-to-python-object conversion for you, which in the case of a ManyToManyField is ultimately represented by a QuerySet in python.

A date field returns date objects, IntegerField an integer, CharFields a string, etc. in the same way via form cleaning.

If you want a list of group_names, you'd need to explicitly iterate through the objects in the QuerySet and pull their group_nm attribute.

            group_names = [x.group_nm for x in form.cleaned_data['groups']]

Answer 2

I'm not sure you need to do all that in your view. You can directly save the form in the view without manually creating the objects and manipulating them.

Also, you need to get the id of activity so that you can update existing activity instance.

Update the urls.py to have these urls to have act_id:

url(r'^activity_app/save/(?P<act_id>\d+)/$', 'activity_app.views.activity_save_page'),
url(r'^activity_app/save/$', 'activity_app.views.activity_save_page'),

I would change the view to:

def activity_save_page(request, act_id=None):
    act_inst = None
    try:
        if act_id:
           act_inst = Activity.objects.get(id=act_id)
    except Exception:
        pass
    if request.method == 'POST':
        form = ActivitySaveForm(request.POST, instance=act_inst)
        if form.is_valid():
            return HttpResponseRedirect('/activity/')
    else:
        form = ActivitySaveForm(instance=act_inst)
    variables = RequestContext(request, {
        'form': form
        })
    return render_to_response('activity_save.html', variables)