Question

给出以下模型

class Camp(models.Model):
    camp_id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=45)
    LEVEL_CHOICES = (
        ("junior", "Junior"),
        ("adventure", "Adventure"),
    )
    level = models.CharField(choices=LEVEL_CHOICES, max_length=9)
    CAPACITY_CHOICES = [(i, i) for i in range(1, 101, 1)]
    capacity = models.IntegerField(choices=CAPACITY_CHOICES)
    start_date = models.DateField()
    end_date = models.DateField()
    open_date = models.DateField()
    closed_date = models.DateField()
    fee = models.FloatField()

    def size(self):
        """Returns the number of registrations for this camp"""
        size = Camp.objects
               .filter(registration__camp_id=self.camp_id)
               .count()
        return size

    def is_full(self):
        """Returns False if size of this camp is less than its capacity,
        otherwise returns True"""
        is_full = False if self.size() < self.capacity else True
        return is_full

    def is_open(self):
        """Returns True if the camp is open for registration,
        otherwise returns False"""
        is_open = True if self.open_date 
                          <= timezone.now().date() 
                          < self.closed_date 
                       else False
        return is_open

    def is_active(self):
        """Returns True if the camp is currently in session,
        otherwise returns False"""
        is_active = True if self.start_date 
                            <= timezone.now().date()
                            <= self.end_date 
                         else False
        return is_active

    def __str__(self):
        name = self.name + " " + self.level
        return name

class Registration(models.Model):
    registration_id = models.AutoField(primary_key=True)
    # other fields omitted
    camp = models.ForeignKey(Camp)
    creation_date = models.DateTimeField(auto_now_add=True, editable=False)

    def __str__(self):
        return str(self.registration_id)

以下表格

class RegistrationForm(forms.ModelForm):
    class Meta:
        model = Registration
        fields = ['camp']

是否可以使用各种Camp模型方法（例如is_full，is_open等）来选择在RegisterForm实例所在的模板中呈现哪些复选框？有没有办法通过视图的上下文或模板中的RegistrationForm对象访问这些方法？

理想情况下，我想隐藏is_open（）返回false的任何Camp实例。我还想为Camp实例上的输入标记呈现HTML类属性“waitlisted”，为is_full（）返回true。像

这样的东西

<input type="checkbox" class="waitlisted" ...>Camp Week 10</input>

Answer 1

知道了！

您可以使用表单字段的.field.queryset属性访问模型实例的QuerySet和方法，如下所示。

{% for camp in registration_form.camp.field.queryset %}
    <p{% if camp.is_full %} class="waitlisted"{% endif %}>
        <label>{{ camp }}</label>
        <input type="checkbox" name="camps" />
    </p>
{% endfor %}

我相信这只适用于需要零参数的模型方法，但足以满足我的需求。

我可以在使用该模型作为外键的表单中呈现模型属性吗？

1 个答案: