Question

我正在如下所示的模型中创建对象。我想要做的是使用UpdateView更新“ class_list”。该更新似乎回溯到我对象的模型窗体，该模型窗体中包含一个干净的例程，这会导致问题。

class ClassroomForm(ModelForm):
    class Meta:
        model = Classroom
        fields = ['course_name', 'course_block','class_list']

    def clean(self):
        try:
            Classroom.objects.get(course_block=self.cleaned_data['course_block'])
            self.redirect = True
            raise forms.ValidationError("Exists already")
        except Classroom.DoesNotExist:
            pass
        return self.cleaned_data

我现在正在为同一模型实现UpdateView。视图很简单：

class BlockUpdateView(UpdateView):
    model = Classroom
    fields = ['class_list']
    success_url = reverse_lazy('classroom:blocklist')

update_classroom_view = BlockUpdateView.as_view()

这是从下面的模板代码调用的：

{% for block in classroom_blocks %}
    <li>{{ block.get_course_block_display }}<a href ="{% url 'classroom:blockUpdate' block.id %}" class="button">EDIT</a><a href ="{% url 'classroom:blockDelete' block.id %}" class="button">DELETE</a></li>
{% empty %}
    <li>No classes set up yet.</li>
{% endfor %}

我成功进入了可以更新模型的视图。进行编辑后，按Submit，然后出现以下错误：

Exception Type:     KeyError
Exception Value: 'course_block'
Exception Location:     C:\Users\dwsmith\mysite\classroom\models.py in clean, line 59

line 59: Classroom.objects.get(course_block=self.cleaned_data['course_block'])

我想知道在这种情况下是否以及如何使用UpdateView。但是，情况还有一个问题。 “ class_list”是我随后解析并迭代以在Student类中创建新对象的名称的列表。由于我正在编辑class_list并提交新列表，因此我认为可能必须先删除所有现有的Student对象，然后再通过分析已编辑的class_list创建新的Student对象。下面显示了“课堂”和“学生”模型以及我如何解析class_list。

class Classroom(models.Model):
    COURSE_NAME = (
        ('MA8', 'Math 8'),
        ('SC10', 'Science 10'),
        ('PH11', 'Physics 11'),
        ('PH12', 'Physics 12'),
    )
    BLOCK_NUMBER = (
        ('11', 'Block 1-1'),
        ('12', 'Block 1-2'),
        ('13', 'Block 1-3'),
        ('14', 'Block 1-4'),
        ('21', 'Block 2-1'),
        ('22', 'Block 2-2'),
        ('23', 'Block 2-3'),
        ('24', 'Block 2-4'),
    )
    class_list = models.TextField()
    course_name = models.CharField(max_length=20, choices=COURSE_NAME)
    course_block = models.CharField(max_length=10, choices=BLOCK_NUMBER)
    group_size = models.IntegerField(default=3)

    def __str__(self):
        return self.get_course_block_display()

    def save(self, *args, **kwargs):
        super(Classroom, self).save(*args, **kwargs)
        # overrides the default save function to parse the class list
        studentList = []
        studentList = self.class_list.split('\n')

        for line in studentList:
            line = line.strip('\r')
            s = Student.objects.create(nickname = line, attend = True, classroom = self)

class Student(models.Model):
    classroom = models.ForeignKey(Classroom, on_delete=models.CASCADE)
    student_first = models.CharField(default='John', max_length=30)
    student_last = models.CharField(default='Smith', max_length=30)
    nickname = models.CharField(default='JohnS', max_length=31)
    attend = models.BooleanField(default=True)

I have a 35 second view that shows the use and intended use of UpdateView.

UpdateView为KeyError提供cleaned_data

0 个答案: