Retrieving models from form with ModelMultipleChoiceField - django

Question

I am having difficulties with forms, specifically ModelMultipleChoiceField.
I've pieced together this code from various examples, but it sadly doesn't work.
I would like to be able to:
Search for some Works on work_search.html
Display the results of the search, with checkboxes next to each result
Select the Works I want, via the checkboxes
After pressing Add, display which works were selected.
I believe everything is okay except the last part. The page simply displays "works" :(
Here is the code - sorry about the length.
Models.py
class Work(models.Model):
title = models.CharField(max_length=200)
artist = models.CharField(max_length=200)
writers = models.CharField(max_length=200)
def __unicode__(self):
return self.title + ' - ' + self.artist
forms.py
class WorkSelectForm(forms.Form):
def __init__(self, queryset, *args, **kwargs):
super(WorkSelectForm, self).__init__(*args, **kwargs)
self.fields['works'] = forms.ModelMultipleChoiceField(queryset=queryset, widget=forms.CheckboxSelectMultiple())
views.py
def work_search(request):
query = request.GET.get('q', '')
if query:
qset = (
Q(title__icontains=query) |
Q(artist__icontains=query) |
Q(writers__icontains=query)
)
results = Work.objects.filter(qset).distinct()
form = WorkSelectForm(results)
return render_to_response("work_search.html", {"form": form, "query": query })
else:
results = []
return render_to_response("work_search.html", {"query": query })
def add_works(request):
#if request.method == POST:
form = WorkSelectForm(request.POST)
#if form.isvalid():
items = form.fields['works'].queryset
return render_to_response("add_works.html", {"items":items})
work_search.html
{% extends "base.html" %}
{% block content %}
<h1>Search</h1>
<form action="." method="GET">
<label for="q">Search: </label>
<input type="text" name="q" value="{{ query|escape }}">
<input type="submit" value="Search">
</form>
{% if query %}
<h2>Results for "{{ query|escape }}":</h2>
<form action="add_works" method="post">
<ul>
{% if form %}
{{ form.as_ul }}
{% endif %}
</ul>
<input type="submit" value="Add">
</form>
{% endif %}
{% endblock %}
add_works.html
{% extends "base.html" %}
{% block content %}
{% if items %}
{% for item in items %}
{{ item }}
{% endfor %}
{% else %}
<p>Nothing selected</p>
{% endif %}
{% endblock %}

Answer 1

In add_works, you're not constructing your WorkSelectForm the right way. It's expecting as a first parameter the queryset of possible/authorized choices, then the POST data.
Also, you're not accessing the selected works correctly from the form. You have to use is_valid method on the form, then use cleaned_data as described in the doc.
From what I see in your work_search view, there's no restriction on which Work objects you can search then add to the result, so you could do simply:
def add_works(request):
#if request.method == POST:
form = WorkSelectForm(Work.objects.all(), request.POST)
if form.is_valid():
# the items are in form.cleaned_data['works']
items = form.cleaned_data['works']
return render_to_response("add_works.html", {"items":items})
else:
# handle error case here
...