Django: How can I create a multiple select form?

Question

I'm beginner in Django/Python and I need to create a multiple select form. I know it's easy but I can't find any example. I know how to create a CharField with a widget but I get confused of all the options inside fields.py.

For example I don't know which one of the followings is best for a multiple select form.

'ChoiceField', 'MultipleChoiceField',
'ComboField', 'MultiValueField',
'TypedChoiceField', 'TypedMultipleChoiceField'

And here is the form I need to create.

        <form action="" method="post" accept-charset="utf-8">
        <select name="countries" id="countries" class="multiselect" multiple="multiple">
            <option value="AUT" selected="selected">Austria</option>
            <option value="DEU" selected="selected">Germany</option>
            <option value="NLD" selected="selected">Netherlands</option>
            <option value="USA">United States</option>
        </select>
        <p><input type="submit" value="Continue &rarr;"></p>
    </form>

EDIT:

One more small question. If I want to add to each option one more attribute like data:

 <option value="AUT" selected="selected" data-index=1>Austria</option>

How can I do it?

Thanks for any help!

Answer 1

I think CheckboxSelectMultiple should work according to your problem.

In your forms.py, write the below code:

from django import forms


class CountryForm(forms.Form):
    OPTIONS = (
        ("AUT", "Austria"),
        ("DEU", "Germany"),
        ("NLD", "Neitherlands"),
    )
    Countries = forms.MultipleChoiceField(widget=forms.CheckboxSelectMultiple,
                                          choices=OPTIONS)

In your views.py, define the following function:

def countries_view(request):
    if request.method == 'POST':
        form = CountryForm(request.POST)
        if form.is_valid():
            countries = form.cleaned_data.get('countries')
            # do something with your results
    else:
        form = CountryForm

    return render_to_response('render_country.html', {'form': form},
                              context_instance=RequestContext(request))

In your render_country.html:

<form method='post'>
    {% csrf_token %}
    {{ form.as_p }}
    <input type='submit' value='submit'>
</form>

Answer 2

I did it in this way :

forms.py

class ChoiceForm(ModelForm):
    class Meta:
        model = YourModel

    def __init__(self, *args, **kwargs):
        super(ChoiceForm, self).__init__(*args, **kwargs)
        self.fields['countries'] =  ModelChoiceField(queryset=YourModel.objects.all()),
                                             empty_label="Choose a countries",)

urls.py

from django.conf.urls.defaults import * 
from django.views.generic import CreateView
from django.core.urlresolvers import reverse

urlpatterns = patterns('',
    url(r'^$',CreateView.as_view(model=YourModel, get_success_url=lambda: reverse('model_countries'),
        template_name='your_countries.html'), form_class=ChoiceForm, name='model_countries'),)

your_countries.html

<form action="" method="post">
    {% csrf_token %}
    {{ form.as_table }}
    <input type="submit" value="Submit" />
</form> 

It is works fine in my example, If you need something more, just ask me!!

Answer 3

Regarding to my second question this is the solution. An extending class:

from django import forms
from django.utils.encoding import force_unicode
from itertools import chain
from django.utils.html import escape, conditional_escape

class Select(forms.Select):
    """
    A subclass of Select that adds the possibility to define additional 
    properties on options.

    It works as Select, except that the ``choices`` parameter takes a list of
    3 elements tuples containing ``(value, label, attrs)``, where ``attrs``
    is a dict containing the additional attributes of the option.
    """
    def render_options(self, choices, selected_choices):
        def render_option(option_value, option_label, attrs):
            option_value = force_unicode(option_value)
            selected_html = (option_value in selected_choices) and u' selected="selected"' or ''
            attrs_html = []
            for k, v in attrs.items():
                attrs_html.append('%s="%s"' % (k, escape(v)))
            if attrs_html:
                attrs_html = " " + " ".join(attrs_html)
            else:
                attrs_html = ""
            return u'<option value="{0}"{1}{2}>{3}</option>'.format(
                escape(option_value), selected_html, attrs_html, 
                conditional_escape(force_unicode(option_label))
                )
            '''
            return u'<option value="%s"%s%s>%s</option>' % (
                escape(option_value), selected_html, attrs_html,
                conditional_escape(force_unicode(option_label)))
            '''
        # Normalize to strings.
        selected_choices = set([force_unicode(v) for v in selected_choices])
        output = []
        for option_value, option_label, option_attrs in chain(self.choices, choices):
            if isinstance(option_label, (list, tuple)):
                output.append(u'<optgroup label="%s">' % escape(force_unicode(option_value)))
                for option in option_label:
                    output.append(render_option(*option))
                output.append(u'</optgroup>')
            else:
                output.append(render_option(option_value, option_label,
                    option_attrs))
        return u'\n'.join(output)

class SelectMultiple(forms.SelectMultiple, Select):
    pass

Example:

OPTIONS = [
        ["AUT", "Australia", {'selected':'selected', 'data-index':'1'}],
        ["DEU", "Germany", {'selected':'selected'}],
        ["NLD", "Neitherlands", {'selected':'selected'}],
        ["USA", "United States", {}]
    ]

Answer 4

ModelMultipleChoiceField is your friend. A CharField is capable of storing one selection, but not multiple, without some extra work, which I would recommend against.

API doc for ModelMultipleChoiceField

Answer 5

You can also define countries field in your form class as

Countries = forms.MultipleChoiceField(widget=forms.SelectMultiple,
                                             choices=OPTIONS_TUPPLE)

I don't know which one is better in SelectMultiple and CheckboxSelectMultiple but it also works.

For more details you can use django documentation about widgets.

Answer 6

Working with widget=forms CheckboxSelectMultiple is quite difficult when you want to select multiple values. (Remember Multiple select is for ManytoMany key Field)

In this condition SelectMultiple is better as you can select multiple items with ctrl or select all items with ctrl+a.

class MyModalForm(forms.ModelForm):
    class Meta:
    model = MyModel
        widgets = {            
            'products': forms.SelectMultiple(attrs={'required': True})
        }

if you wants dynamic values for multiple select you can do this with init

class MyModalForm(forms.ModelForm):
    class Meta:
    model = MyModel
        widgets = {            
            'products': forms.SelectMultiple(attrs={'required': True})
        }
    def __init__(self, *args, **kwargs):
        selected_products = kwargs.pop('selected_products', None)   ##queryset returned from function
        self.fields['products'].queryset = selected_products
        self.fields['orders'].queryset = OrderModal.objects.filter(pk=2)