SearchView wrapper for haystack to bring it in line with Django 1.3+ CBV

generic.py

from functools import update_wrapper

from django.conf import settings
from django.utils.decorators import classonlymethod
from django.views.generic.base import TemplateResponseMixin

from haystack.query import SearchQuerySet
from haystack.forms import FacetedSearchForm
from haystack.views import FacetedSearchView as HaystackFacetedSearchView


class FacetedSearchView(TemplateResponseMixin, HaystackFacetedSearchView):
    template_name = None
    facets = None
    filter_models = None
    order_by = None
    paginate_by = getattr(settings, 'HAYSTACK_SEARCH_RESULTS_PER_PAGE', 20)
    form_class = FacetedSearchForm

    def __init__(self, *args, **kwargs):
        form_class = kwargs.get('form_class', self.form_class)
        super(FacetedSearchView, self).__init__(*args, **kwargs)
        # Needed to switch out the default form class.
        self.form_class = form_class
        if not self.results_per_page and self.paginate_by:
            self.results_per_page = self.paginate_by

    def get_context_data(self):
        return {}

    def extra_context(self):
        ctx = super(FacetedSearchView, self).extra_context()
        ctx.update(self.get_context_data())
        return ctx

    def get_facets(self):
        if not self.facets:
            return []
        return self.facets

    def get_filter_model(self, models=None):
        if models:
            return (models + self.filter_models)
        return self.filter_models

    def get_order_by_fields(self):
        return self.order_by

    def get_extra_filters(self):
        return {}

    def get_search_queryset(self, queryset=None, models=None):
        searchqueryset = queryset or self.searchqueryset or SearchQuerySet()
        searchqueryset = searchqueryset.filter(
            **self.get_extra_filters()
        )
        for facet_field in self.get_facets():
            searchqueryset = searchqueryset.facet(facet_field)
        # check we should filter by model
        filter_models = self.get_filter_model(models)
        if filter_models:
            searchqueryset = searchqueryset.models(*filter_models)
        # check for defined order by list
        if self.get_order_by_fields():
            searchqueryset = searchqueryset.order_by(
                *self.get_order_by_fields()
            )
        return searchqueryset

    @property
    def template(self):
        """ Provide property to be backwards compatible with haystack. """
        template_names = self.get_template_names()
        if template_names:
            return template_names[0]
        return None

    def get(self, request, *args, **kwargs):
        self.searchqueryset = self.get_search_queryset()
        return super(FacetedSearchView, self).__call__(request)

    def __call__(self, request, *args, **kwargs):
        self.request = request
        self.kwargs = kwargs
        return self.get(request, *args, **kwargs)

    @classonlymethod
    def as_view(cls, *initargs, **initkwargs):
        def view(request, *args, **kwargs):
            return cls(*initargs, **initkwargs)(request, *args, **kwargs)
        update_wrapper(view, cls, updated=())
        return view