带过滤器参数的django自定义管理器

Question

我想添加一个可以从模板调用的自定义管理器,但不会影响整个模型(例如管理员视图),并且会监听请求中的参数集(user_profile).

以下是我到目前为止的情况:

models.py:

class CurrentQuerySet(models.query.QuerySet):
    def current(self):
            return self.filter(id=1) ## this simplified filter test works..
class CurrentManager(models.Manager):
    use_for_related_fields = True
    def get_query_set(self):
            return CurrentQuerySet(self.model)
    def current(self, *args, **kwargs):
            return self.get_query_set().current(*args, **kwargs)

对于模型B定义:

    objects = CurrentManager()

模板调用:

{% for b in a.b_set.current %}

但是一旦我尝试将参数传递给该过滤器(在这种情况下是存储在用户配置文件中的日期),该方法就不会返回任何结果.

例如:

models.py

class CurrentQuerySet(models.query.QuerySet):
    def current(self,my_date): 
            return self.filter(valid_from__lte=my_date) 

showA.html

{% for b in a.b_set.current(request.user.get_profile.my_date) %}

我没有从模板中传递参数,而是尝试在view.py中设置它

@login_required
def showA(request,a_id):
    my_date = request.user.get_profile().my_date
    a = A.objects.get(id=a_id)
    t = loader.get_template('myapp/showA.html')
    c = RequestContext(request,{'a':a,'my_date':my_date,})
    return HttpResponse(t.render(c))

我在这里错过(或误解)哪一部分？

谢谢

[R

编辑

这里的模型.如上所述,在这个例子中,它是一个简单的1:n关系,但在其他情况下也可以是m:n.

class A(models.Model):
    #objects = CurrentManager()
    a = models.CharField(max_length=200)
    description = models.TextField(null=True,blank=True)
    valid_from = models.DateField('valid from')
    valid_to = models.DateField('valid to',null=True,blank=True)
    def __unicode__(self):
            return self.a

class B(models.Model):
    #objects = models.Manager()
    objects = CurrentManager()
    a = models.ForeignKey(A)
    b = models.CharField(max_length=200)
    screenshot = models.ManyToManyField("Screenshot",through="ScreenshotToB")
    description = models.TextField(null=True,blank=True)
    valid_from = models.DateField('valid from')
    valid_to = models.DateField('valid to',null=True,blank=True)
    def __unicode__(self):
            return self.b

编辑-2

接受的答案适用于至少一种关系.
如果是更嵌套的数据模型,此方法似乎无法提供预期的结果:

models.py

class C(models.Model):
    objects = CurrentManager()
    b = models.ForeignKey(A)
    c = models.CharField(max_length=200)
    description = models.TextField(null=True,blank=True)
    valid_from = models.DateField('valid from')
    valid_to = models.DateField('valid to',null=True,blank=True)
    def __unicode__(self):
            return self.c

views.py

@login_required
def showA(request,a_id):
    a = A.objects.get(id=a_id)
    my_date = request.user.get_profile().my_date
    b_objects = a.b_set.current(my_date)
    c_objects = b_objects.c_set.current(my_date)
    t = loader.get_template('controltool2/showA.html')
    c = RequestContext(request,{'a':a,'b_objects':b_objects,'c_objects':c_objects,})
    return HttpResponse(t.render(c))

这会返回错误:'QuerySet' object has no attribute 'c_set'.

Answer 1

我简化了它:

class CurrentManager(models.Manager):
    def current(self, my_date):
        return super(CurrentManager, self).get_query_set().filter(valid_from__lte=my_date) 

然后像这样使用它:

a = A.objects.get(id=a_id)
my_date = request.user.get_profile().my_date
b_objects = a.b_set.objects.current(my_date)

然后只需将a传递给模板,因为过滤后的对象使用以下方法访问它们:

{% for b in b_objects %}

希望这可以帮助!

编辑(按请求者):

我必须按如下方式调整它以使其工作:

a = A.objects.get(id=a_id)
my_date = request.user.get_profile().my_date
b_objects = a.b_set.current(my_date)

这引发了一个错误:"'RelatedManager'对象没有属性'对象'"

a.b_set.objects.current(my_date)