django-constance generic view

from operator import itemgetter

from django.utils.formats import localize
from django.views.generic.edit import FormView
from django.utils.translation import ugettext_lazy as _

from constance import settings, LazyConfig
from constance.admin import ConstanceForm


config = LazyConfig()


class ConstanceConfigView(FormView):
    form_class = ConstanceForm
    template_name = 'dashboard/constance/config.html'

    def __init__(self, *args, **kwargs):
        if 'fields' in kwargs:
            self.fields = kwargs.pop('fields')
        else:
            self.fields = settings.CONFIG.keys()
        super(ConstanceConfigView, self).__init__(*args, **kwargs)

    def get_context_data(self, **kwargs):
        context = super(ConstanceConfigView, self).get_context_data(**kwargs)
        context['config'] = []
        form_class = self.get_form_class()
        form = self.get_form(form_class)
        initial = self.get_initial()
        for name, (default, help_text) in settings.CONFIG.items():
            value = initial.get(name)
            if value is None:
                value = getattr(config, name)
            context['config'].append({
                'name': name,
                'default': localize(default),
                'help_text': _(help_text),
                'value': localize(value),
                'modified': value != default,
                'form_field': form[name],
            })
        context['config'].sort(key=itemgetter('name'))
        return context

    def get_initial(self):
        data = super(ConstanceConfigView, self).get_initial()
        default_initial = ((name, default) for name, (default, help_text) in settings.CONFIG.items() if name in self.fields)
        initial = dict(default_initial, **dict(config._backend.mget([k for k in settings.CONFIG.keys() if k in self.fields])))
        data.update(initial)
        return data

    def form_valid(self, form):
        form.save()
        return super(ConstanceConfigView, self).form_valid(form)