Django-tables2:如何使用order_by访问器 [英] Django-tables2: how to order_by accessor
问题描述
假设我们有一列,例如:
Say we have a column like:
num_member = tables.Column(accessor = 'members.count', verbose_name = 'number of members' )
当我尝试在模板中对它进行排序时,它会引发:
When I tried to sort this in the template, it raises:
Field Error: Cannot resolve keyword u'count' into field
我阅读了文档,并说我们可以通过传入某种 accessor
来使用 order_by
,但是请问究竟如何做到这一点?
I read the document and it says we can use order_by
by passing in some sort of accessor
, but how exactly do we do this please?
推荐答案
对于类似于Model的property方法的函数,您可以使用 accessor
直接访问它.例如:
For function like Model's property method, you can access it directly using accessor
. For example:
Class MyModel(models.Model):
data= models.CharField(max_length=255)
@property
def print_function(self):
return 'hello world'
#Table class
class MyTable(tables.Table):
data= tables.Column(accessor='print_function')
class Meta:
model = MyModel
fields = ('data')
使用上述方法,您可以使用访问器在表中显示不同种类的数据:
Using the above method, you can show different kinds of data in table using accessor:
Class SomeModel(models.Model):
some_data= models.CharField(max_length=255)
data= models.ManyToManyField(MyModel)
@property
def count_function(self):
some_data= self.data.objects.count() #returns count of the objects
return some_data
#Table class
class SomeTable(tables.Table):
data= tables.Column(accessor='count_function')
class Meta:
model = SomeModel
fields = ('data')
访问器可用于直接访问相关外键模型的字段值,例如:
And accessor can be used for directly accessing related foreignkey model's field value like:
Class SomeModel(models.Model):
somedata= models.ForeignKey(MyModel)
#Table class
class MyTable(tables.Table):
data= tables.Column(accessor='somedata.data')
class Meta:
model = SomeModel
fields = ('data')
编辑
让我们举一个例子说明如何使用 order_by
:
Lets give an example of how order_by
can be used:
#Class Based view, I am subclassing ListView and SingleTableView here for example
class MyView(ListView, SingleTableView):
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['table'].order_by = '-last_updated' #last_updated is a datetimefield in model
return context
在上面的代码中,我所做的是,我正在更改上下文中表数据的顺序,该顺序稍后将在模板中呈现.
In the above code, what I have done is that, I am changing the order of the table data in context which will later be rendered in template.
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