## 1 forms渲染错误信息

```python
1 form对象.errors 字典
2 name对象.errors

## 视图函数
def register(request):
    if request.method=='GET':
        form=myforms.MyForm()
        return render(request, 'register.html',{'form':form})
    else:
        form=myforms.MyForm(request.POST)
        if form.is_valid():
            return redirect('http://www.baidu.com')
        else:
            return render(request, 'register.html',{'form':form})
## 模板
 <form action="" method="post" novalidate>
    {% for foo in form %}
    <div class="form-group">
        <label for="">{{ foo.label }}</label>
            {{ foo }}
            <span class="text-danger pull-right">{{ foo.errors }}</span>
        </div>
    {% endfor %}
    <div class="text-center">
        <input type="submit" value="提交" class="btn btn-danger">
    </div>
</form>
```



## 2 forms组件参数配置

```python
# 定制模板中的显示样式，及配置类
# widget=widgets.PasswordInput(attrs={'class': 'form-control'})
# 错误信息中文显示
    error_messages={'min_length': '太短了小伙子'}


class MyForm(forms.Form):
    # 校验这个字段，最大长度是32，最小长度是3
    name = forms.CharField(required=False, max_length=32, min_length=3, label='用户名',
                           widget=widgets.TextInput(attrs={'class': 'form-control'}),
                           error_messages={'min_length': '太短了小伙子'})
    password = forms.CharField(required=False, max_length=32, min_length=3, label='密码',
                               widget=widgets.PasswordInput(attrs={'class': 'form-control'}),
                               error_messages={'min_length': '太短了小伙子'})
    re_password = forms.CharField(required=False, max_length=32, min_length=3, label='确认密码',
                                  widget=widgets.PasswordInput(attrs={'class': 'form-control'}),
                                  error_messages={'min_length': '太短了小伙子'})
    email = forms.EmailField(label='邮箱', error_messages={'required': '小惠子，这个必填'},
                             widget=widgets.TextInput(attrs={'class': 'form-control'}))
    age = forms.IntegerField(max_value=200, min_value=0, label='年龄',
                             widget=widgets.TextInput(attrs={'class': 'form-control'}))
    text = forms.CharField(label='个人简介', widget=widgets.Textarea(attrs={'class': 'form-control'}))
    date = forms.CharField(label='出生日期', widget=widgets.DateInput(attrs={'class': 'form-control'}))
    
    
    

```



## 3 局部钩子和全局钩子

```python
## 局部钩子的使用
    # 1 在自定义的Form类中写 clean_字段名
    # 2 取出字段的真正值，name=self.cleaned_data.get('name')
    # 3 判断自己的规则，如果判断失败，抛出ValidationError
    # 4 如果通过，return name
# 局部钩子
    def clean_name(self):
        # name对应的值，如何取到？
        name = self.cleaned_data.get('name')
        if name.startswith('sb'):
            # 不让校验通过
            raise ValidationError('不能以sb开头')
        else:
            # 校验通过，返回name
            return name
# 全局钩子
    def clean(self):
        # name=self.cleaned_data.get('name')
        # print(name)
        password = self.cleaned_data.get('password')
        re_password = self.cleaned_data.get('re_password')
        if password == re_password:
            return self.cleaned_data
            # return {'lqz':"nb"}
        else:
            raise ValidationError('两次密码不一致')
```



## 4 cookie session token

```python
1 https://www.cnblogs.com/liuqingzheng/articles/8990027.htmlp
    
2 cookie:   保存在客户端浏览器上的键值对
3 session：保存在服务端的键值对
4 token：加密的键值对，如果放在客户端浏览器上，它就叫cookie，  服务端签发的加密字符串

head.{name:lqz,age:18}.eseetsweasdca

base64加码：

asdfasfd.asdfasdf.asdfasdfaeraew

后端校验：
用这个token去查我的账户余额，向银行发请求，银行校验通过，是银行给你的，---》返回你的余额
head.{name:lqz,age:18}.eseetsweasdca

head.{name:egon,age:18}.eseetsweasdca

```

## 5 django中cookie的使用

```python
def cookie_test(request):
    # 浏览器向我这个地址发一个请求，就在浏览器写入 name = lqz

    obj=HttpResponse('ok')
    obj.set_cookie('name','egon')  # 写入到浏览器了，在http响应头里：cookie: name=lqz
    obj.set_cookie('age','19')  # 写入到浏览器了，在http响应头里：cookie: name=lqz
    return obj


def get_cookie(request):

    print(request.COOKIES)
    print(request.COOKIES.get('name'))
    return HttpResponse('我拿了你传过来的cookie')


def delete_cookie(request):


    obj=HttpResponse('我删掉了你 name 这个cookie ')
    obj.delete_cookie('name')
    return obj
```

# views.py
from django.shortcuts import render, HttpResponse, redirect
from app01 import app01_forms
# Create your views here.


def register(request):
    if request.method == 'GET':
        form = app01_forms.MyForm()
        return render(request, 'register.html', {'form': form})
    else:
        form = app01_forms.MyForm(request.POST)
        if form.is_valid():
            print(form.cleaned_data)
            return HttpResponse('校验通过。')
        else:
            error = form.errors.get('__all__')
            print(error)
            return render(request, 'register.html', {'form': form, 'error': error})


def add_cookie(request):
    obj = HttpResponse('add_cookie')
    obj.set_cookie('name','welt')       # set_cookie('key','value')   添加 或 修改 cookie
    return obj


def get_cookie(request):
    print(request.COOKIES)       # 获取cookie
    print(request.COOKIES.get('name'))       # 获取cookie
    return HttpResponse('获取cookie')


def del_cookie(request):
    obj = HttpResponse('删除cookie')
    obj.delete_cookie('name')           # HttpResponse对象.delete_cookie('key')   删除cookie
    return obj

# app01_forms.py
from django import forms
from django.forms import widgets, ValidationError


class MyForm(forms.Form):
    username = forms.CharField(max_length=32, min_length=3, required=True, label='用户名',
                               widget=widgets.TextInput(attrs={'class': 'form-control'}),
                               error_messages={'required': '用户名不能为空！', 'min_length': '长度不少于3位！'})
    # error_messages控制错误类型对应的错误信息
    # 先导入：from django.forms import widgets
    # widget 控制渲染模板时生成的输入框类型，括号中可以为标签添加属性，例：attrs={'class': 'form-control'} --> 添加一个form-control类
    password = forms.CharField(max_length=32, min_length=5, label='密码',
                               widget=widgets.PasswordInput(attrs={'class': 'form-control'}),
                               error_messages={'required': '密码不能为空！', 'min_length': '长度不少于5位！'})
    re_password = forms.CharField(max_length=32, min_length=5, label='密码',
                                  widget=widgets.PasswordInput(attrs={'class': 'form-control'}),
                                  error_messages={'required': '密码不能为空！', 'min_length': '长度不少于5位！'})
    email = forms.EmailField(max_length=32, label='邮箱', widget=widgets.TextInput(attrs={'class': 'form-control'}))
    age = forms.IntegerField(max_value=200, required=False, label='年龄',
                             widget=widgets.TextInput(attrs={'class': 'form-control'}))
    text = forms.CharField(max_length=200, label='个人简介', required=False,
                           widget=widgets.Textarea(attrs={'class': 'form-control'}))
    birthday = forms.DateField(label='出生日期', widget=widgets.DateInput(attrs={'type': 'date', 'class': 'form-control'}),
                               required=False)

    # 局部钩子（方法，方法名：clean_字段名）
    # 高级校验：例：name不能以sb开头
    def clean_username(self):
        # 只要程序能走到这个方法，则表示前面该字段的校验已经通过
        name = self.cleaned_data.get('username')  # 通过cleaned_data获取当前对象的username
        if name.startswith('sb'):
            raise ValidationError('用户名不能以sb开头！')
        else:
            return name

    # 全局钩子
    def clean(self):
        # 只要程序能走到这个方法，则表示前面的校验以及局部钩子都已经通过
        password = self.cleaned_data.get('password')
        re_password = self.cleaned_data.get('re_password')
        if password == re_password:
            return self.cleaned_data
        else:
            raise ValidationError('密码不一致！')
            # 全局钩子的raise错误通过views中的对应函数使用form.errors.get('__all__')来获取，并传到前端显示

// register.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <link rel="stylesheet" href="/static/bootstrap/css/bootstrap.min.css">
    <title>Title</title>
</head>
<body>
<hr>

<div class="container-fluid">
    <div class="row">
        <div class="col-md-6 col-md-offset-3">
            <h1>半自动渲染模板3(用的最多)</h1>
            <form action="" method="post" novalidate>           <!--novalidate取消前端校验-->
                {% for foo in form %}
                    <div class="form-group">
                        <label for="">{{ foo.label }}</label>
                        {{ foo }}
                        <span class="text-danger pull-right">{{ foo.errors }}</span>   <!--每一个foo都有自己的errors属性-->
                    </div>
                {% endfor %}
                <div class="text-center">
                    <input type="submit" value="提交" class="btn btn-danger">
                    <span class="text-primary">{{ error }}</span>
                </div>

            </form>

        </div>
    </div>
</div>


</body>
</html>