Django Form Is Valid 不产生任何错误但返回 False答案

【问题标题】：Django Form Is Valid not producing any errors but returning FalseDjango Form Is Valid 不产生任何错误但返回 False
【发布时间】：2020-10-07 15:31:26
【问题描述】：

我正在尝试使用表单更新现有模型行（将选项添加到具有先前条目的现有 ManyToMany 字段），但是当我使用 is_valid() 它返回 false 时，我已经通过几种方式检查了错误但是没有显示错误我在我的模板中使用过：

{% if form.errors %}
{% for field in form %}
    {% for error in field.errors %}
        <div class="errorlogin">
            <strong>{{ error|escape }}</strong>
        </div>
    {% endfor %}
{% endfor %}
{% for error in form.non_field_errors %}
    <div class="errorlogin">
        <strong>{{ error|escape }}</strong>
    </div>
{% endfor %}
{% endif %}

在我看来，在 is_valid 之后和 is_valid 函数被调用之前：

print(form.errors)

我的代码如下：视图.py

def lessonRecord(request,id):
if request.method == "POST":
    id = Lessons.objects.get(id=id)
    form = forms.LessonAddForm(request.POST,instance=id)
    if form.is_valid():
        form.save()
        return redirect('lessons:lessonsView')
    else:
        print(form.errors)
else:
    id = Lessons.objects.get(id=id)
    form = forms.LessonAddForm(instance=id , user=request.user)
return render(request,'lessons/lesson_record.html',{'id':id,'form':form})

forms.py

class LessonAddForm(forms.ModelForm):
def __init__(self, user,*args, **kwargs):
    super(LessonAddForm, self).__init__(*args, **kwargs)
    self.fields['attendees'].queryset = CustomUser.objects.filter(
        Q(username=user) |
        Q(customuser__username=user)
    )
class Meta:
    model = models.Lessons
    fields = ['attendees']

【问题讨论】：

标签： django django-views

【解决方案1】：

问题在于视图和表单。我没有通过发布请求传递用户

def lessonRecord(request,id):
if request.method == "POST":
    id = Lessons.objects.get(id=id)
    form = forms.LessonAddForm(request.POST,user=request.user,instance=id)
    if form.is_valid():
        form.save()
        return redirect('lessons:lessonsView')

forms.py

class LessonAddForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
    user = kwargs.pop('user', None)
    super(LessonAddForm, self).__init__(*args, **kwargs)
    self.fields['attendees'].queryset = CustomUser.objects.filter(
        Q(username=user) |
        Q(customuser__username=user)
    )

【讨论】：