同时验证两个字段 [英] Validating two fields at the same time

问题描述

我正在看这篇文档：

https://docs.djangoproject.com/en/1.8/ref/forms/validation/#cleaning-和验证字段 - 依赖于每个其他

该文档说明了字段依赖关系如何完成，但我有一点点不同问题：

说我有一个有两个字段的模型：

 类MyModel（models.Model）：
 field1 = models.CharField（max_length = 200）
 field2 = models.CharField（max_length = 200）
  

并且说这两个字段之一是隐藏的，所以modelform看起来像这样：

  class MyModelForm（forms.ModelForm）：
 class Meta：
 ... 
 
 widgets = {'field2'：forms.HiddenImput（） 
  

现在，当用户填写ou表格，然后（在 clean_field1 ）也填写 field2 。现在，我想报告 field2 发生的任何错误，作为关于 field1 的错误。这是因为目前用户不知道他做错了什么！

我试图做的是在ModelForm定义中：

  def clean（self）：
 cleaning_data = super（MyModelForm，self）.clean（）
＃ $ b return clean_data 
  

这是Django页面上呈现的内容。但是，问题是当执行 clean 方法时，字典 self.errors 是空的，所以我不知道该怎么办...

解决方案

我不知道我的答案。但是，假设您正在使用 field1 数据，以生成 field2 值。您可以使用自定义方法生成它，并将其分配给 __ init __ 方法中的字段。这将给你一个很好的方法来清理这两个领域。

  class MyModelForm（forms.ModelForm）：
 
 def __init __（self，* args，** kwargs）
 super（MyModelForm，self）.__ init __（* args，** kwargs）
 
＃现在可以使用field1数据生成field2数据
 self.data [ 'field2'] = self.field [1] * 154220 
 
 class Meta：
 widgets = {'field2'：forms.HiddenInput（）} 
 
 
 def clean_field1（self）：
 ##这里您只能对field1进行验证。 
 ##这样做不像field2不是现在的。 
 
 
 def clean_field2（self）：
 ##这里只能对field2进行验证。 
 ##这样做不像field1没有exisited。 
 
 def clean（self）：

在这里你可以验证两个字段
 raise ValidationError如果看到有什么问题
例如，如果你想确保field1！= field2 

 field1 = self.cleaned_data ['field1'] 
 field2 = self.cleaned_data ['field2'] 
 
如果field1 == field2：
 raise ValidationError（错误消息，不会告诉用户field2是错误的。）
 
返回clean_data 
  

---

更新

如果您希望 clean 方法在特定字段中引发错误：

请注意，您的Form.clean（）覆盖引起的任何错误都不会与任何字段特别相关联的
。他们进入一个特殊的
字段（称为全部），如果需要，您可以通过
non_field_errors（）方法访问。如果要将错误
附加到表单中的特定字段，则需要调用add_error（）。

所以从Django文档可以使用 add_error（）来做你想要实现的内容。

代码可以这样

  def clean（self ）

在这里你可以验证两个字段
 raise ValidationError如果你看到任何错误的话
例如，如果你想确保field1！= field2 

 field1 = self.cleaned_data ['field1'] 
 field2 = self.cleaned_data ['field2'] 
 
 if field1 == field2： 
＃这会引发field1错误的错误。不是所有的形式
 self.add_error（field1，你的错误消息）
 
返回clean_data 
  

请注意，上述方法是Django 1.7及更高版本的新方法。

https://docs.djangoproject.com/en/dev/ref/forms/api/#django.forms.Form.add_error

I am looking at this piece of documentation:

https://docs.djangoproject.com/en/1.8/ref/forms/validation/#cleaning-and-validating-fields-that-depend-on-each-other

The documentation explains how field dependency can be done, but I have a slightly different problem:

Say I have a model with two fields:

class MyModel(models.Model):
    field1 = models.CharField(max_length=200)
    field2 = models.CharField(max_length=200)

And say that one of the two fields is hidden, so the modelform looks like so:

class MyModelForm(forms.ModelForm):
    class Meta:
        ...

        widgets = {'field2': forms.HiddenImput()}

Now, when the user fills out the form, I then (on clean_field1) also fill field2. Now, I want to report any error that happens to field2 as an error about field1. This is because at the moment, the user does not know what he did wrong!

What I tried to do was, in the ModelForm definition:

def clean(self):
    cleaned_data = super(MyModelForm, self).clean()
    # Do something here
    return cleaned_data

As this is what is presented on the Django page. However, the problem is that when the clean method is executed, the dictionary self.errors is empty, so I don't know what to do...

解决方案

I am not sure about my answer. However, let's assume that you are using the field1 data in order to generate field2 value. You can generate it using a custom method and assign it to the field in the __init__ method. Which will give you a good way to cleaning the two fields later.

class MyModelForm(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        super(MyModelForm, self).__init__(*args, **kwargs)

        # now lets generate field2 data using field1 data.. 
        self.data['field2'] = self.field[1] * 154220

    class Meta:
        widgets = {'field2': forms.HiddenInput()}    


    def clean_field1(self):
        ## Here you can do validation for field1 only.
        ## Do it like field2 is not exisited. 


    def clean_field2(self):
        ## Here you can do validation for field2 only.
        ## Do it like field1 is not exisited. 

    def clean(self):
        """
        In here you can validate the two fields
        raise ValidationError if you see anything goes wrong. 
        for example if you want to make sure that field1 != field2
        """
        field1 = self.cleaned_data['field1']
        field2 = self.cleaned_data['field2']

        if field1 == field2:
            raise ValidationError("The error message that will not tell the user that field2 is wrong.")

        return cleaned_data

---

Update

In case you want the clean method to raise the error in a specific field:

Note that any errors raised by your Form.clean() override will not be associated with any field in particular. They go into a special "field" (called all), which you can access via the non_field_errors() method if you need to. If you want to attach errors to a specific field in the form, you need to call add_error().

So from Django documentation you can use add_error() to do what you want to achieve.

The code can be in this way

def clean(self):
    """
    In here you can validate the two fields
    raise ValidationError if you see anything goes wrong. 
    for example if you want to make sure that field1 != field2
    """
    field1 = self.cleaned_data['field1']
    field2 = self.cleaned_data['field2']

    if field1 == field2:
        # This will raise the error in field1 errors. not across all the form
        self.add_error("field1", "Your Error Message")

    return cleaned_data

Note that the above method is new with Django 1.7 and above.

https://docs.djangoproject.com/en/dev/ref/forms/api/#django.forms.Form.add_error

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