(Django)修剪charField的空格

Question

如何从Django中的charField末尾删除空格(trim)？

这是我的模型,你可以看到我已经尝试过使用干净的方法,但这些方法永远不会运行.

我也尝试过name.strip(),models.charField().strip()但这些都不起作用.

有没有办法强制charField自动修剪？

谢谢.

from django.db import models
from django.forms import ModelForm
from django.core.exceptions import ValidationError
import datetime

class Employee(models.Model):
    """(Workers, Staff, etc)"""
    name                = models.CharField(blank=True, null=True, max_length=100)

    def save(self, *args, **kwargs):
        try:
            # This line doesn't do anything??
            #self.full_clean()
            Employee.clean(self)
        except ValidationError, e:
            print e.message_dict

        super(Employee, self).save(*args, **kwargs) # Real save

    # If I uncomment this, I get an TypeError: unsubscriptable object
    #def clean(self):
    #   return self.clean['name'].strip()

    def __unicode__(self):
        return self.name

    class Meta:
        verbose_name_plural = 'Employees'

    class Admin:pass


class EmployeeForm(ModelForm):
    class Meta:
        model = Employee

    # I have no idea if this method is being called or not  
    def full_clean(self):       
        return super(Employee), self.clean().strip()
        #return self.clean['name'].strip()

编辑:更新了我最新版本的代码.我不确定我做错了什么,因为它仍然没有剥离空白(修剪)名称字段.

Answer 1

当您使用ModelForm实例创建/编辑模型时,可以保证调用模型的clean()方法.因此,如果要从字段中删除空格,只需向模型添加clean()方法(无需编辑ModelForm类):

class Employee(models.Model):
    """(Workers, Staff, etc)"""
    name = models.CharField(blank=True, null=True, max_length=100)

    def clean(self):
        if self.name:
            self.name = self.name.strip()

我发现以下代码片段很有用 - 它修剪了所有模型字段的空白,这些字段是CharField或TextField的子类(因此这也捕获了URLField字段),而无需单独指定字段:

def clean(self):
    for field in self._meta.fields:
        if isinstance(field, (models.CharField, models.TextField)):
            value = getattr(self, field.name)
            if value:
                setattr(self, field.name, value.strip())

有人正确地指出你不应该在名称声明中使用null = True.最佳做法是避免字符串字段为null = True,在这种情况下,上述内容简化为:

def clean(self):
    for field in self._meta.fields:
        if isinstance(field, (models.CharField, models.TextField)):
            setattr(self, field.name, getattr(self, field.name).strip())

Answer 2

必须调用模型清理(它不是自动的),所以self.full_clean()在你的保存方法中放置一些.
http://docs.djangoproject.com/en/dev/ref/models/instances/#django.db.models.Model.full_clean

至于表单,您需要返回已剥离的已清理数据.

return self.cleaned_data['name'].strip()

不知何故,我认为你只是试图做一堆不起作用的东西.请记住,表单和模型是两个非常不同的东西.

查看有关如何验证表单的表单文档 http://docs.djangoproject.com/en/dev/ref/forms/validation/

super(Employee), self.clean().strip() makes no sense at all!

这是您的代码修复:

class Employee(models.Model):
    """(Workers, Staff, etc)"""
    name = models.CharField(blank=True, null=True, max_length=100)

    def save(self, *args, **kwargs):
        self.full_clean() # performs regular validation then clean()
        super(Employee, self).save(*args, **kwargs)


    def clean(self):
        """
        Custom validation (read docs)
        PS: why do you have null=True on charfield? 
        we could avoid the check for name
        """
        if self.name: 
            self.name = self.name.strip()


class EmployeeForm(ModelForm):
    class Meta:
        model = Employee


    def clean_name(self):
        """
        If somebody enters into this form ' hello ', 
        the extra whitespace will be stripped.
        """
        return self.cleaned_data.get('name', '').strip()

Answer 3

Django 1.9 提供了一种简单的方法来实现这一点。通过使用strip默认为 True的参数，您可以确保修剪前导和尾随空格。您只能在表单字段中执行此操作，以确保修剪用户输入。但这仍然不能保护模型本身。如果您仍然想这样做，您可以使用上述任何一种方法。

有关更多信息，请访问https://docs.djangoproject.com/en/1.9/ref/forms/fields/#charfield

Answer 4

如果要修剪这么多数据字段,为什么不尝试扩展CharField？

from django.db import models
from django.utils.translation import ugettext_lazy as _

class TrimCharField(models.CharField):
   description = _(
       "CharField that ignores leading" 
       " and trailing spaces in data")

   def get_prep_value(self, value)
       return trim(super(TrimCharField, self
           ).get_prep_value(value))

   def pre_save(self, model_instance, add):
       return trim(super(TrimCharField, self
           ).pre_save(model_instance, add))

更新:对于Django版本<= 1.7,如果你想扩展字段,你将使用models.SubfieldBase元类.所以这里会是这样的:

class TrimCharField(six.with_metaclass(
    models.SubfieldBase, models.CharField)):