Django系列之form渲染表单后css样式丢失

最通用的form写法

我们经常看各大网站上写这样的form写法

class SYSAdminPhysicalForm(forms.ModelForm): ???‘‘‘ ???this form for idc‘s admin ???‘‘‘ ???class Meta: ???????model = models.Machinepro ???????exclude = ["m_inside_ip","m_outside_ip","order"] ???business_unit = forms.CharField(required=False,label="所属业务",disabled=True,) ???def __init__(self, *args, **kwargs): ???????super(SYSAdminPhysicalForm, self).__init__(*args, **kwargs) ???????for field_name in self.base_fields: ???????????field = self.base_fields[field_name] ???????????if field_name in ["m_ipmi_user","m_ipmi_passwd"]: ???????????????field.widget.attrs.update({‘class‘: ‘form-control‘}) ???????????else: ???????????????field.widget.attrs.update({‘class‘: ‘form-control‘,"disabled":True})

写完这个form后，你重启django后第一次通过浏览器打开这个form表单，你会发现css样式是丢失的，特别是我那个disabled属性，一旦丢失，别人就可以修改我的表单了，所以后果非常严重。所以需要采取下面的方法来纠正这个bug

方法1：__new__写法

__init__是实例初始化执行，那么我们就改成实例化的时候执行，也就是使用new

 ???def __new__(cls, *args, **kwargs): ???????obj = super(SYSAdminPhysicalForm, cls).__new__(cls,*args, **kwargs) ???????for field_name in obj.base_fields: ???????????field = obj.base_fields[field_name] ???????????if field_name in ["m_ipmi_user","m_ipmi_passwd"]: ???????????????field.widget.attrs.update({‘class‘: ‘form-control‘}) ???????????else: ???????????????field.widget.attrs.update({‘class‘: ‘form-control‘,"disabled":True})

方法2：fields 替换掉base_fields

这个最简单了，把base_fields直接用fields替换就解决了

 ???????def __init__(self, *args, **kwargs): ???????super(SYSAdminPhysicalForm, self).__init__(*args, **kwargs) ???????for field_name in self.fields: ???????????field = self.fields[field_name] ???????????if field_name in ["m_ipmi_user","m_ipmi_passwd"]: ???????????????field.widget.attrs.update({‘class‘: ‘form-control‘}) ???????????else: ???????????????field.widget.attrs.update({‘class‘: ‘form-control‘,"disabled":True}) 

任选一种方法后，任凭django重启多少回，不管你第几次打开表单页面，都不会丢失css样式啦！