尝试将会话从模型保存传递到视图

Question

我对我的一个模型进行了一些自定义验证，并根据验证失败生成错误。我想将这些错误传递给我的视图。

class TimeSheet(models.Model):

    O = "Open"
    S = "Submitted"
    A = "Approved"
    R = "Needs review"

    STATUS_CHOICES = (
    (O, "Open"),
    (S, "Submitted"),
    (A, "Approved"),
    (R, "Needs Reviewing"),
    )

    start_date = models.DateField()
    end_date = models.DateField()
    person_id = models.ForeignKey(Person)
    status = models.CharField(max_length= 50, default="Open", choices=STATUS_CHOICES)
    submitted_id = models.IntegerField(default=0)
    approved_id = models.IntegerField(default=0)
    submitted_date = models.DateTimeField(auto_now_add=True, blank=True)
    approved_date = models.DateTimeField(auto_now_add=True, blank=True)

    def get_absolute_url(self):
        return reverse('tande:timesheet', kwargs={'id': self.id})

    def save(self, *args, **kwargs):
        ok_to_continue = True
        start_date = self.start_date
        end_date = self.end_date

        if end_date < start_date:
            error = "ERROR: Start date must be before end date"
            ok_to_continue = False

        # make sure both dates are in the same month
        if start_date.month != end_date.month:
            error = "ERROR: Start and end dates must be in the same month"
            ok_to_continue = False

        # VALIDATION
        if ok_to_continue:
            super(TimeSheet, self).save(*args, **kwargs)
        else:
            print error
            self.request.session['error_from_save'] = error

但是，这会引发错误：

AttributeError: 'TimeSheet' 对象没有属性 'request'

为什么self.request.session 不起作用？还有其他方法可以将其传递回我的视图吗？

Answer 1

覆盖模型的save() 方法不是进行验证的首选方法。您应该为模型中的每个字段提供validators 属性并为它们提供custom-written validators，或者在override the clean_fieldname methods of your form 所在的（模型）表单中进行验证。

您不能从模型的 save 方法将内容传递回视图的原因是可能并不总是从视图调用 save 方法。例如，它可以从 shell 调用。所以不会总是有视图或会话可以返回。