Allow to filter by borrower in item admin listing view

        return False

class BorrowerFilter(admin.SimpleListFilter):

    title = 'détenteur actuel'

    parameter_name = 'user'

    def _filter_loans(self, items_queryset, user_pk=None):

        qs = Loan.objects.running().filter(item__in=items_queryset)

        if user_pk is not None:

            qs.filter(user=user_pk)

        return qs

    def lookups(self, request, model_admin):

        # Get relevant (and authorized) users only

        relevant_items = model_admin.get_queryset(request)

        users = set()

        for loan in self._filter_loans(relevant_items):

            users.add((loan.user.pk, loan.user))

        return users

    def queryset(self, request, queryset):

        if self.value():

            loans_qs = self._filter_loans(queryset).filter(

                user__pk=self.value(),

            )

            return queryset.filter(loans__in=loans_qs)

        else:

            return queryset

@admin.register(Item)

class ItemAdmin(admin.ModelAdmin):

    list_display = (

    )

    list_filter = (

        AvailabilityFilter, 'type', 'storage',

        'buy_date', OwnerFilter)

        'buy_date', BorrowerFilter, OwnerFilter)

    search_fields = (

        'designation', 'mac_address', 'serial',

        'owner__email', 'owner__nickname',