A select multiple widget that allows for filtering and lazy loading. It is inspired by Django's FilteredSelectMultiple widget, but with a few improvements:

• Lazy loading and asynchronous loading for the initial choices make it quicker to work with very large data sets.
• The ability to specify the field and lookup types the filter is being applied on.
• Easy to use both inside the admin and out since all of the required javascript and (minimal) css are included in the widget.

django-fsm-widget requires Django 1.5 or later.

To install the latest version of django-fsm-widget:

pip install git+git://github.com/DirectEmployers/django-fsm-widget.git@master

To use the widget in a form, specify the widget when creating the field:

from django import forms
from django.core.urlresolvers import reverse_lazy
from example.models import Meatball, Noodle, Spaghetti
from fsm.widget import FSM


class SpaghettiForm(forms.ModelForm):
    class Meta:
        model = Spaghetti

    meatball_widget = FSM('Meatballs', reverse_lazy('meatball_filter')
    meatballs = forms.ModelMultipleChoiceField(Meatball.objects.all(), widget=meatball_widget)

The available params for the FSM widget are:

• verbose_name (required): A name for the object that the widget is being used on that is used when describing the object. Usually the field label will work for this.
• url (required): The url used for filtering/autocomplete and lazy loading. The endpoint should be a subclass of the FSMView view class covered below.
• async (default==False): True if you want to load the initial choices after the page has loaded, otherwise False. Note: If async==True and lazy==False the initial choices will be loaded twice.
• attrs: Form element attributes. Same as most other Django widgets.
• choices: The initial choices to select from.
• lazy (default==False): Prevent loading of initial choices until filter terms have been entered by the user.

The FSMView class serves as an endpoint for the filter. There needs to be at least one subclass of FSMView for every model that's being filtered using the FSM widget. Setting up the filter endpoint is as easy as:

class MeatballFilter(FSMView):
    model = Meatball

The fields that are filtered on can be specified by adding the variable fields = ('fieldname__lookuptype', 'fieldname', ...) to the subclass.

An example of all of this can be found in the example/ directory of this project. The example project is fully functional and can be run using runserver.

MIT