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 wirite 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)

EDIT : I thought of writing complete code flow So that you can understand it better. Because you might get confuse

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>

I hope this helps.Let me know if it that is what you were expecting.

Answer 2

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 3

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 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

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", {}]
    ]