How to use the rdmo.core.views.ObjectPermissionMixin function in rdmo

try:
            current_snapshot = context['project'].snapshots.get(pk=self.kwargs.get('snapshot_id'))
        except Snapshot.DoesNotExist:
            current_snapshot = None

        context.update({
            'current_snapshot': current_snapshot,
            'snapshots': list(context['project'].snapshots.values('id', 'title')),
            'answers_tree': get_answers_tree(context['project'], current_snapshot),
            'export_formats': settings.EXPORT_FORMATS
        })

        return context


class ProjectAnswersExportView(ObjectPermissionMixin, DetailView):
    model = Project
    queryset = Project.objects.all()
    permission_required = 'projects.view_project_object'

    def get_context_data(self, **kwargs):
        context = super(ProjectAnswersExportView, self).get_context_data(**kwargs)

        try:
            current_snapshot = context['project'].snapshots.get(pk=self.kwargs.get('snapshot_id'))
        except Snapshot.DoesNotExist:
            current_snapshot = None

        context.update({
            'format': self.kwargs.get('format'),
            'title': context['project'].title,
            'answers_tree': get_answers_tree(context['project'], current_snapshot)

permission_required = 'projects.rollback_snapshot_object'
    template_name = 'projects/snapshot_rollback.html'

    def get_permission_object(self):
        return self.get_object().project

    def post(self, request, *args, **kwargs):
        snapshot = self.get_object()

        if 'cancel' not in request.POST:
            snapshot.rollback()

        return HttpResponseRedirect(reverse('project', args=[snapshot.project.id]))


class MembershipCreateView(ObjectPermissionMixin, RedirectViewMixin, CreateView):
    model = Membership
    form_class = MembershipCreateForm
    permission_required = 'projects.add_membership_object'

    def dispatch(self, *args, **kwargs):
        self.project = get_object_or_404(Project.objects.all(), pk=self.kwargs['project_id'])
        return super(MembershipCreateView, self).dispatch(*args, **kwargs)

    def get_permission_object(self):
        return self.project

    def get_form_kwargs(self):
        kwargs = super(MembershipCreateView, self).get_form_kwargs()
        kwargs['project'] = self.project
        return kwargs

kwargs = super(MembershipCreateView, self).get_form_kwargs()
        kwargs['project'] = self.project
        return kwargs


class MembershipUpdateView(ObjectPermissionMixin, RedirectViewMixin, UpdateView):
    model = Membership
    queryset = Membership.objects.all()
    fields = ('role', )
    permission_required = 'projects.change_membership_object'

    def get_permission_object(self):
        return self.get_object().project


class MembershipDeleteView(ObjectPermissionMixin, RedirectViewMixin, DeleteView):
    model = Membership
    queryset = Membership.objects.all()
    permission_required = 'projects.delete_membership_object'

    def delete(self, *args, **kwargs):
        self.obj = self.get_object()

        if (self.request.user in self.obj.project.owners) or is_site_manager(self.request.user):
            # user is owner or site manager
            if is_last_owner(self.obj.project, self.obj.user):
                log.info('User "%s" not allowed to remove last user "%s"', self.request.user.username, self.obj.user.username)
                return HttpResponseBadRequest()
            else:
                log.info('User "%s" deletes user "%s"', self.request.user.username, self.obj.user.username)
                success_url = reverse('project', args=[self.get_object().project.id])
                self.obj.delete()

model = Project
    queryset = Project.objects.all()
    form_class = ProjectForm
    permission_required = 'projects.change_project_object'

    def get_form_kwargs(self):
        catalogs = Catalog.objects.filter_current_site().filter_group(self.request.user)

        form_kwargs = super().get_form_kwargs()
        form_kwargs.update({
            'catalogs': catalogs
        })
        return form_kwargs


class ProjectUpdateTasksView(ObjectPermissionMixin, RedirectViewMixin, UpdateView):
    model = Project
    queryset = Project.objects.all()
    form_class = ProjectTasksForm
    permission_required = 'projects.change_project_object'

    def get_form_kwargs(self):
        tasks = Task.objects.filter_current_site().filter_group(self.request.user)

        form_kwargs = super().get_form_kwargs()
        form_kwargs.update({
            'tasks': tasks
        })
        return form_kwargs


class ProjectUpdateViewsView(ObjectPermissionMixin, RedirectViewMixin, UpdateView):

elif self.request.user == self.obj.user:
            # user wants to remove him/herself
            log.info('User "%s" deletes himself.', self.request.user.username)
            success_url = reverse('projects')
            self.obj.delete()
            return HttpResponseRedirect(success_url)

        else:
            log.info('User "%s" not allowed to remove user "%s"', self.request.user.username, self.obj.user.username)
            return HttpResponseForbidden()

    def get_permission_object(self):
        return self.get_object().project


class ProjectAnswersView(ObjectPermissionMixin, DetailView):
    model = Project
    queryset = Project.objects.all()
    permission_required = 'projects.view_project_object'
    template_name = 'projects/project_answers.html'
    no_catalog_error_template = 'projects/project_error_no_catalog.html'

    def get(self, request, *args, **kwargs):
        self.object = self.get_object()

        if self.object.catalog is None:
            return redirect('project_error', pk=self.object.pk)
        else:
            context = self.get_context_data(object=self.object)
            return self.render_to_response(context)

    def get_context_data(self, **kwargs):

raise Http404

        try:
            context['rendered_view'] = context['view'].render(context['project'], context['current_snapshot'])
        except TemplateSyntaxError:
            context['rendered_view'] = None

        context.update({
            'snapshots': list(context['project'].snapshots.values('id', 'title')),
            'export_formats': settings.EXPORT_FORMATS
        })

        return context


class ProjectViewExportView(ObjectPermissionMixin, DetailView):
    model = Project
    queryset = Project.objects.all()
    permission_required = 'projects.view_project_object'

    def get_context_data(self, **kwargs):
        context = super(ProjectViewExportView, self).get_context_data(**kwargs)

        try:
            context['current_snapshot'] = context['project'].snapshots.get(pk=self.kwargs.get('snapshot_id'))
        except Snapshot.DoesNotExist:
            context['current_snapshot'] = None

        try:
            context['view'] = context['project'].views.get(pk=self.kwargs.get('view_id'))
        except View.DoesNotExist:
            raise Http404

class ProjectExportXMLView(ObjectPermissionMixin, DetailView):
    model = Project
    queryset = Project.objects.all()
    permission_required = 'projects.export_project_object'

    def render_to_response(self, context, **response_kwargs):
        serializer = ExportSerializer(context['project'])
        xmldata = XMLRenderer().render(serializer.data)
        response = HttpResponse(prettify_xml(xmldata), content_type="application/xml")
        response['Content-Disposition'] = 'filename="%s.xml"' % context['project'].title
        return response


class ProjectExportCSVView(ObjectPermissionMixin, DetailView):
    model = Project
    queryset = Project.objects.all()
    permission_required = 'projects.export_project_object'

    def stringify_answers(self, answers):
        if answers is not None:
            return '; '.join([self.stringify(answer) for answer in answers])
        else:
            return ''

    def stringify(self, el):
        if el is None:
            return ''
        else:
            return re.sub(r'\s+', ' ', str(el))

model = Project
    queryset = Project.objects.all()
    form_class = ProjectTasksForm
    permission_required = 'projects.change_project_object'

    def get_form_kwargs(self):
        tasks = Task.objects.filter_current_site().filter_group(self.request.user)

        form_kwargs = super().get_form_kwargs()
        form_kwargs.update({
            'tasks': tasks
        })
        return form_kwargs


class ProjectUpdateViewsView(ObjectPermissionMixin, RedirectViewMixin, UpdateView):
    model = Project
    queryset = Project.objects.all()
    form_class = ProjectViewsForm
    permission_required = 'projects.change_project_object'

    def get_form_kwargs(self):
        views = View.objects.filter_current_site().filter_catalog(self.object.catalog).filter_group(self.request.user)

        form_kwargs = super().get_form_kwargs()
        form_kwargs.update({
            'views': views
        })
        return form_kwargs


class ProjectDeleteView(ObjectPermissionMixin, RedirectViewMixin, DeleteView):

request.FILES['uploaded_file']
        except KeyError:
            return HttpResponseRedirect(self.success_url)
        else:
            tempfilename = handle_uploaded_file(request.FILES['uploaded_file'])

        tree = read_xml_file(tempfilename)
        if tree is None:
            log.info('Xml parsing error. Import failed.')
            return render(request, self.parsing_error_template, status=400)
        else:
            import_project(request.user, tree)
            return HttpResponseRedirect(self.success_url)


class SnapshotCreateView(ObjectPermissionMixin, RedirectViewMixin, CreateView):
    model = Snapshot
    form_class = SnapshotCreateForm
    permission_required = 'projects.add_snapshot_object'

    def dispatch(self, *args, **kwargs):
        self.project = get_object_or_404(Project.objects.all(), pk=self.kwargs['project_id'])
        return super(SnapshotCreateView, self).dispatch(*args, **kwargs)

    def get_permission_object(self):
        return self.project

    def get_form_kwargs(self):
        kwargs = super(SnapshotCreateView, self).get_form_kwargs()
        kwargs['project'] = self.project
        return kwargs

kwargs = super(SnapshotCreateView, self).get_form_kwargs()
        kwargs['project'] = self.project
        return kwargs


class SnapshotUpdateView(ObjectPermissionMixin, RedirectViewMixin, UpdateView):
    model = Snapshot
    queryset = Snapshot.objects.all()
    fields = ['title', 'description']
    permission_required = 'projects.change_snapshot_object'

    def get_permission_object(self):
        return self.get_object().project


class SnapshotRollbackView(ObjectPermissionMixin, RedirectViewMixin, DetailView):
    model = Snapshot
    queryset = Snapshot.objects.all()
    permission_required = 'projects.rollback_snapshot_object'
    template_name = 'projects/snapshot_rollback.html'

    def get_permission_object(self):
        return self.get_object().project

    def post(self, request, *args, **kwargs):
        snapshot = self.get_object()

        if 'cancel' not in request.POST:
            snapshot.rollback()

        return HttpResponseRedirect(reverse('project', args=[snapshot.project.id]))