如何重构Django1.9中基于类的视图中的重复方法

Question

我有一个基于类的视图叫做PalletContentProductionView

@method_decorator(PermissionManager.production_worker_required, name='dispatch')
class PalletContentProductionView(APIView):
    """
    Update a Pallet Content count and/or product
    """
    def put(self, request, pk):
        pallet_content = QuickFind.get_pallet_content_or_404(pallet_content_id=pk)

        def validate_pending_and_created_by_user(pallet_content, user=request.user):
            if not pallet_content.pending():
                raise PermissionDenied("Non-Pending pallet content cannot be updated by production worker")
            EntryFormHelper.throw_403_when_not_created_by_user(pallet_content=pallet_content, user=user)
        return update_pallet_content(request, pallet_content, validate_pending_and_created_by_user)

    """
    Delete pallet only if pallet content is pending and creater by user
    """
    def delete(self, request, pk):
        pallet_content = QuickFind.get_pallet_content_or_404(pallet_content_id=pk)

        def validate_pending_and_created_by_user(pallet_content, user=request.user):
            if pallet_content.pending() is False:
                raise PermissionDenied("Non-Pending pallet content cannot be updated by production worker")
            EntryFormHelper.throw_403_when_not_created_by_user(pallet_content=pallet_content, user=user)
        return delete_pallet_content(request, pallet_content, validate_pending_and_created_by_user)

我想知道如何重构以避免四行重复？你知道吗

这四条线是：

def validate_pending_and_created_by_user(pallet_content, user=request.user):
        if not pallet_content.pending():
            raise PermissionDenied("Non-Pending pallet content cannot be updated by production worker")
        EntryFormHelper.throw_403_when_not_created_by_user(pallet_content=pallet_content, user=user)

我试着把它拉出来，放在PalletContentProductionView内，并与put和delete方法相邻，但这是错误的。你知道吗

Answer 1

只需创建一个生成相应函数的方法：

@method_decorator(PermissionManager.production_worker_required, name='dispatch')
class PalletContentProductionView(APIView):
    def put(self, request, pk):
        pallet_content = self.get_pallet_content(pk)
        return update_pallet_content(
            request, pallet_content,
            self.generate_callback(request, pk)
        )

    def delete(self, request, pk):
        pallet_content = self.get_pallet_content(pk)
        return delete_pallet_content(
            request, pallet_content,
            self.generate_callback(request, pk)
        )

    def get_pallet_content(self, pallet_content_pk):
        return QuickFind.get_pallet_content_or_404(pallet_content_id=pk)

    def generate_callback(self, request, pallet_content):
        def validate_pending_and_created_by_user(pallet_content, user=request.user):
            if not pallet_content.pending():
                raise PermissionDenied("Non-Pending pallet content cannot be updated by production worker")
            EntryFormHelper.throw_403_when_not_created_by_user(pallet_content=pallet_content, user=user)
        return validate_pending_and_created_by_user

注意，这里我们还使用get_pallet_content来避免QuickFind.get_pallet_content_or_404(pallet_content_id=pk)的重复。你知道吗

另外，请注意您应该使用if not something:而不是if something is False:。你知道吗