django - TypeError 如何从用户实例中获取外键实例答案

【问题标题】：django - TypeError how to get instance of a foreignkey from the user instancedjango - TypeError 如何从用户实例中获取外键实例
【发布时间】：2018-04-25 16:22:08
【问题描述】：

我收到以下类型错误，这是由于查看此实例所致。您可以在下面看到的模型中，Employee 是与 User 的一对一关系，Company 是 Employee 的外键。我如何通过获取 company 实例来解决这个问题？或者是什么问题。

这就是问题所在：

companysetting_form = CompanySettingEdit(instance = request.user.employee.company)

下面是类型错误

TypeError at /employee/companysettings/    
__init__() got an unexpected keyword argument 'instance'

Request Method: GET
Request URL:    http://127.0.0.1:8000/employee/companysettings/
Django Version: 1.11.7
Exception Type: TypeError
Exception Value:    
__init__() got an unexpected keyword argument 'instance'
Exception Location: /Users/megasap/Documents/project/railercom/railercomapp/views.py in employee_companysettings, line 83
Python Executable:  /Users/megasap/Documents/project/myvirtualenv/railercom/bin/python
Python Version: 3.6.3
Python Path:    
['/Users/megasap/Documents/project/railercom',
 '/Library/Frameworks/Python.framework/Versions/3.6/lib/python36.zip',
 '/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6',
 '/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/lib-dynload',
 '/Users/megasap/Documents/project/myvirtualenv/railercom/lib/python3.6/site-packages']

下面是我的代码：

https://gitlab.com/firdausmah/railercom/blob/master/railercomapp/views.py

@login_required(login_url='/employee/sign-in/')
def employee_companysettings(request):

companysetting_form = CompanySettingEdit(instance = request.user.employee.company)  <---- this is the problem

if request.method == "POST":
    companysetting_form = CompanySettingEdit(request.POST, instance = request.user.employee.company)

    if companysetting_form.is_valid():
        companysetting_form.save()

return render(request, 'employee/account.html', {
    "companysetting_form":companysetting_form
    })

https://gitlab.com/firdausmah/railercom/blob/master/railercomapp/forms.py

class CompanySettingEdit(forms.Form):
    name = forms.CharField(max_length=50, required=False)
    tel = forms.CharField(max_length=50, required=False)
    address_1 = forms.CharField(max_length=50, required=False)
    address_2 = forms.CharField(max_length=50, required=False)
    address_zip = forms.CharField(max_length=50, required=False)
    address_city = forms.CharField(max_length=50, required=False)
    address_state = forms.CharField(max_length=50, required=False)
    address_country = forms.CharField(max_length=50, required=False)

    class Meta:
        model = Company
        fields = ("name", "tel", "address_1", "address_2", "address_zip",
                  "address_city","address_state","address_country")

https://gitlab.com/firdausmah/railercom/blob/master/railercomapp/templates/employee/companysettings.html

      <form method="POST" enctype="multipart/form-data">
        {% csrf_token %}
        {% bootstrap_form companysetting_form %}
        <button type="submit" class="btn btn-pink">Update</button>
      </form>

https://gitlab.com/firdausmah/railercom/blob/master/railercomapp/models.py

class Company(models.Model):
    name = models.CharField(max_length=50)
    tel = models.CharField(max_length=15, blank=True)
    address_1 = models.CharField(max_length=50, blank=True)
    address_2 = models.CharField(max_length=50, blank=True)
    address_zip = models.CharField(max_length=20, blank=True)
    address_city = models.CharField(max_length=20, blank=True)
    address_state = models.CharField(max_length=20, blank=True)
    address_country = models.CharField(max_length=20, blank=True)

    logo = models.ImageField(upload_to='company_logo/', blank=False)

    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    def __str__(self):
        return self.name

【问题讨论】：

forms.Form 的构造函数似乎不接受 instance 关键字参数。
感谢您的评论，您能给一些指导吗？此表单有效，但我需要将表单数据保存到模型中。我需要在表单构造函数中有 init 并做一些事情吗？谢谢。 gist.github.com/anonymous/db51370aaf0ce759ab51cb24fc390633

标签： python django view foreign-keys instance

【解决方案1】：

这个问题与外键无关。

Plain Form 子类对模型一无所知，忽略内部 Meta 类，没有 save 方法，也不接受 instance 参数。

要启用所有这些功能，您的表单需要继承 forms.ModelForm。

作为奖励，一旦完成，您可以删除类本身中的所有字段定义，因为它们将从模型定义中获取。

【讨论】：