Form操作之错误信息操作
1. 用户发送请求过来
2. for 循环对字段进行正则表达式的验证 fields.clean(value)
3. 自定义clean_字段() 进行名字段值正确性的校验
4. 自定义clean()的内容校验,会进行异常信息的捕捉
5. post_clean()方法的校验,不允许抛出异常,self.add_error(进行校验)
注意 self.add_error(None, ValidatorError(‘’)) 这里虽然写的是None,但实际上会转换为__all__
Django内部会进行转换的:self.add_error(‘__all__’, ValidatorError(‘’))
settings.py
INSTALLED_APPS = [
...
'app01', # 注册app
]
STATICFILES_DIRS = (os.path.join(BASE_DIR, "statics"),) # 现添加的配置,这里是元组,注意逗号
TEMPLATES = [
...
'DIRS': [os.path.join(BASE_DIR, 'templates')],
]
urls.py
from django.contrib import admin
from django.urls import path
from django.conf.urls import url, include
from app01 import views
urlpatterns = [
url('fm/', views.fm),
]
views.py
from django.shortcuts import render, redirect, HttpResponse
from app01 import models,fields
class Fm(forms.Form):
username = fields.CharField(max_length=32, label='用户名')
email = fields.EmailField(label='邮箱') # 这里是对username字段的内容进行验证的
def _clean_username(self):
data = self.cleaned_data['username']
if (data == 'root'):
return data # 验证通过,返回一个结果给forms.py中full_clean()方法的调用处
else:
from django.core.exceptions import ValidationError
# 这里的异常也是forms.py中full_clean()的异常捕获
raise ValidationError("请使用root用户登录...") # 这里实际上是调用 _clean_form(self)里的clean()进行错误拓展
def clean(self):
data = self.cleaned_data['username']
email = self.cleaned_data['email']
if (data == 'root' and email == 'root@live.com'):
pass # 因为父级别的_post_clean也是什么都不操作
else:
from django.core.exceptions import ValidationError
# 这里的异常是forms._clean_form()的异常捕获
raise ValidationError("用户名或email错误...")
return self.cleaned_data # _post_clean和_clean_form里面的clean()效果同,所以这里隐去
# 这里是个_post_clean里面的Hook,里面的方法体为空
# def _post_clean(self):
# data = self.cleaned_data['username']
# email = self.cleaned_data['email']
# if (data == 'root' and email == 'root@live.com'):
# pass # 因为父级别的_post_clean也是什么都不操作
# else:
# from django.core.exceptions import ValidationError
# # 这里的异常是forms._clean_form()的异常捕获
# raise ValidationError("用户名或email错误...") def fm(request):
if request.method == "GET":
obj = Fm()
return render(request, 'fm.html', {"obj": obj})
else:
obj = Fm(request.POST)
obj.is_valid()
# data = obj.clean() 因为Fm()里面覆写了该方法,所以直接调用cleaned_data获取值即可
data = obj.cleaned_data
error = obj.errors
print('错误信息',error)
print('正确信息:',data)
return render(request, 'fm.html', {"obj": obj})
templates/fm.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
</head>
<body>
{# 模版语言一: 逐个输出内容#}
<h5>模版语言,逐个输出</h5>
{{ obj.username }}
{{ obj.email }}
<hr>
{# 模版语言二: 一次性输出全部内容,如果是as_p,则是在P标签内,as_ul是ul标签 #}
<h5>模版语言,一次性配合lable标签输出全部字段</h5>
{{ obj.as_p }}
{{ obj.as_ul }}
<table>{{ obj.as_table }}</table>
<hr>
<form action="/fm/" method="post">
{{ obj.as_p }}
<input type="submit" value="提交"/>
</form>
</body>
</html>
页面显示;
初始化数据库
python manage.py makemigrations
python manage.py migrate
Form操作之is_valid()源码解析
进入full_clean()方法
full_clean()方法:
_clean_fields()
add_error(name,e)
_clean_form():
_post_form()
Form操作之前台下拉框实时显示数据库内容
问题现象:无法获取数据库内最新的数据
解决一: 调用父类的构造方法,每次调用函数之前重新获取数据
class Fm(forms.Form):
username = fields.CharField(max_length=32, label='用户名')
email = fields.EmailField(label='邮箱')
user_type=fields.ChoiceField(choices=models.UT.objects.values_list('id', 'caption')) def __init__(self, *args, **kwargs):
super(Fm, self).__init__(*args, **kwargs)
self.fields['user_type'].widget.choices = models.UT.objects.all().values_list('id', 'caption')
最终显示内容:
附完整源码:
settings.py
INSTALLED_APPS = [
...
'app01', # 注册app
]
STATICFILES_DIRS = (os.path.join(BASE_DIR, "statics"),) # 现添加的配置,这里是元组,注意逗号
TEMPLATES = [
...
'DIRS': [os.path.join(BASE_DIR, 'templates')],
]
urls.py
from django.contrib import admin
from django.urls import path
from django.conf.urls import url, include
from app01 import views
urlpatterns = [
url('fm/', views.fm),
]
views.py
from django.shortcuts import render, redirect, HttpResponse
from app01 import models
class Fm(forms.Form):
username = fields.CharField(max_length=32, label='用户名')
email = fields.EmailField(label='邮箱')
user_type=fields.ChoiceField(choices=models.UT.objects.values_list('id', 'caption'))
# 方案一:
def __init__(self, *args, **kwargs):
super(Fm, self).__init__(*args, **kwargs)
self.fields['user_type'].widget.choices = models.UT.objects.all().values_list('id', 'caption')
# 方案二:
from django.forms import models as filed_models
# 这里的all()返回的是一个对象,前台页面显示的始终是object,但是看源码又有value值
# 同时这里的limit_choices_to并无明显效果显示,在ModelForm里面效果显著
user_type2 = filed_models.ModelChoiceField(queryset=models.UT.objects.all(),
to_field_name='caption',
limit_choices_to={'id':'(1,3)'},)
# 多选框
user_type3 = filed_models.ModelMultipleChoiceField(queryset=models.UT.objects.all(),
to_field_name='caption',
limit_choices_to={'id': '(1,3)'}, ) def fm(request):
if request.method == "GET":
obj = Fm()
return render(request, 'fm.html', {"obj": obj})
models.py
from django.db import models
class U(models.Model):
id = models.AutoField(primary_key=True) # AutoField必须是主键,才能自定义该列
name = models.CharField(max_length=32)
email = models.CharField(max_length=32)
userType = models.ForeignKey("UT", on_delete=True) # 1对多[无法用自定义,有约束关系] class UT(models.Model):
caption = models.CharField(max_length=32)
def __str__(self):
return self.caption
templates/fm.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
</head>
<body>
{# 模版语言一: 逐个输出内容#}
<h5>模版语言,逐个输出</h5>
{{ obj.username }}
{{ obj.email }}
<hr>
{# 模版语言二: 一次性输出全部内容,如果是as_p,则是在P标签内,as_ul是ul标签 #}
<h5>模版语言,一次性配合lable标签输出全部字段</h5>
{{ obj.as_p }}
{{ obj.as_ul }}
<table>{{ obj.as_table }}</table>
<hr>
<form action="/fm/" method="post">
{{ obj.as_p }}
<input type="submit" value="提交"/>
</form>
</body>
</html>
页面显示;
初始化数据库
python manage.py makemigrations
python manage.py migrate
Form操作更多参考 :http://www.cnblogs.com/wupeiqi/articles/6144178.html