一：什么是ModelForm呢？
Model + Form ==> ModelForm。model和form的结合体，所以有以下功能：
- 数据验证
- 数据库操作
model有操作数据库的字段，form验证也有那几个字段，虽然耦合度降低，但是代码是有重复的。如果利用model里的字段，那是不是form里的字段就不用写了。
二：下面是一个简单是例子：
from django.db import models class CustomerInfo(models.Model):
"""客户表"""
name = models.CharField(max_length=)
contact_type_choices = ((,'QQ'),(,'微信'),(,'手机'))
contact_type = models.SmallIntegerField(choices=contact_type_choices)
contact = models.CharField(max_length=,unique=True,verbose_name="联系方式")
source_choices = ((,'QQ群'),(,'51CTO'),(,'百度推广'),(,'知乎'),(,'转介绍'),(,'其它'))
source = models.SmallIntegerField(choices=source_choices,verbose_name="客户来源")
referral_from = models.ForeignKey("self",blank=True,null=True,verbose_name="转介绍",on_delete=models.CASCADE)
consult_courses = models.ManyToManyField("Course",verbose_name="咨询课程")
consult_content = models.TextField(verbose_name="咨询内容")
status_choices = ((, '未报名'), (, '已报名'), (, '已退学'))
status = models.SmallIntegerField(choices=status_choices,verbose_name="状态")
consultant = models.ForeignKey("UserProfile",verbose_name="课程顾问",on_delete=models.CASCADE)
date = models.DateField(auto_now_add=True)
def __str__(self):
return self.name
models.py
from django.forms import ModelForm
from crm import models
from django import forms class CustomerForm(ModelForm):
class Meta:
model = models.CustomerInfo
fields = '__all__'
exclude = ['consult_content', 'status', 'consult_courses']
readonly_fields = ['contact_type','contact','consultant','referral_from','source'] #并不是真正的设置可读模式，而是用于自定制 def __new__(cls, *args, **kwargs): # cls 就是实例(self)
for field_name in cls.base_fields:
field_obj = cls.base_fields[field_name]
field_obj.widget.attrs.update({'class':'form-control'})
if field_name in cls.Meta.readonly_fields:
field_obj.widget.attrs.update({'disabled':'true'})
# print(cls.Meta)
# print(cls.Meta.exclude)
return ModelForm.__new__(cls) def clean(self):
"""对数据进行验证，此方法需要在form.is_valid()后才能生效"""
# print("cleaned_dtat:", self.cleaned_data)
if self.errors: # 表单级别的错误
raise forms.ValidationError(("Please fix errors before re-submit."))
for field in self.Meta.readonly_fields:
old_field_val = getattr(self.instance,field)
new_form_val = self.cleaned_data[field]
if old_field_val != new_form_val:
self.add_error(field,"Readonly Field: field should be '{value}' ,not '{new_value}' ".\
format(**{'value':old_field_val,'new_value':new_form_val}))
forms
def enrollment(request,enrollment_id):
"""②学员确认信息"""
customer_form = forms.CustomerForm(instance=enrollment_obj.customer) if request.method == "POST":
customer_form = forms.CustomerForm(instance=enrollment_obj.customer,data=request.POST)
if customer_form.is_valid():
customer_form.save()
return HttpResponse('合同正在审核中，请等候...') return render(request,'crm/enrollment.html',locals())
views
注意我们如何在POST和GET情况下传递实例（instance）。
三、Meta的作用：
- ModelForm 通过 Meta 把 db.Field 自动转化为 forms.Field，其中涉及到几步转化
- validators 不变
- 添加 widget 属性，即前端的渲染方式
- 修改 Model 包含的字段，通过 fields 来拿指定字段或者通过 exclude 来排除指定字段
- 修改错误信息
class Meta:
model = models.UserInfo
fields = '__all__'
# fields = ['username','email']
# exclude = ['username']
labels = {
'username': '用户名',
'email': '邮箱',
}
help_texts = {
'username': '...'
}
widgets = {
'username': Fwidgets.Textarea(attrs={'class': 'c1'})
}
error_messages = {
'__all__':{ },
'email': {
'required': '邮箱不能为空',
'invalid': '邮箱格式错误..',
}
}
field_classes = {
# 'email': Ffields.URLField
} # localized_fields=('ctime',)
Meta的另一个例子