第八章

Posted hanwei999

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  1. simple_tag,filter
  2. request
  3. 数据库操作
  4. cookie
  5. session
  6. CSRF
  7. 中间件
  8. 缓存
  9. 信号
  10. Form

 

1,simple_tag,filter

https://www.cnblogs.com/zhaof/p/6253130.html

2,request

request.xxx.getlist 列表

request.Meta(..)
	request.method(POST,GET,PUT)
	requet.path_info
	request.COOKIES
	
a = ‘test‘
return HttpResPOnse(a)
return render
return redirect

a = ‘test‘
response = HttpResponse(a)
response[‘name‘] = ‘alex‘

response.set_cookie()
return response

views

request.POST(request.body)
request.FILES(request.body)

request.xxx.getlist
request.body

request.path_info
request.COOKIES
request.method

3,数据库操作

models.TB.objects.get
models.TB.objects.filter().update()
models.TB.objects.filter().first()
models.TB.objects.filter(**{})
models.TB.objects.filter(**{}).count()
models.TB.objects.filter(双下划线跨表)
models.TB.objects.filter(id__gt=1)
models.TB.objects.filter(id__lt=1)
models.TB.objects.filter(id__gte=1)
models.TB.objects.filter(id__gte=1,name=‘root‘)
models.TB.objects.exclude(id__gte=1)
models.TB.objects.filter(id__in=[1,2,3])


多对多:
	obj.set
	obj.add(1,2,3)
	obj.add([1,2,3])
	obj.remove([1,2,3])
	obj.clear()
	obj.all()
	
models.TB.objects.all()
[obj.obj]
obj.fk.name

models.TB.objects.all().order_by(‘‘)
models.TB.objects.distinct()

4,cookie

1、获取Cookie:
request.COOKIES[‘key‘]
request.get_signed_cookie(key, default=RAISE_ERROR, salt=‘‘, max_age=None)
    参数:
        default: 默认值
           salt: 加密盐
        max_age: 后台控制过期时间
        
2、设置Cookie:
rep = HttpResponse(...) 或 rep = render(request, ...)
 
rep.set_cookie(key,value,...)
rep.set_signed_cookie(key,value,salt=‘加密盐‘,...)
    参数:
        key,              键
        value=‘‘,         值
        max_age=None,     超时时间
        expires=None,     超时时间(IE requires expires, so set it if hasn‘t been already.)
        path=‘/‘,         Cookie生效的路径,/ 表示根路径,特殊的:跟路径的cookie可以被任何url的页面访问
        domain=None,      Cookie生效的域名
        secure=False,     https传输
        httponly=False    只能http协议传输,无法被javascript获取(不是绝对,底层抓包可以获取到也可以被覆盖)
      

由于cookie保存在客户端的电脑上,所以,JavaScript和jquery也可以操作cookie。

<script src=‘/static/js/jquery.cookie.js‘></script>
$.cookie("list_pager_num", 30,{ path: ‘/‘ });

5,session

session通用设置

Django中默认支持Session,其内部提供了5种类型的Session供开发者使用:

数据库(默认)
缓存
文件
缓存+数据库
加密cookie

1、数据库Session
Django默认支持Session,并且默认是将Session数据存储在数据库中,即:django_session 表中。
 
a. 配置 settings.py
 
    SESSION_ENGINE = ‘django.contrib.sessions.backends.db‘   # 引擎(默认)
     
    SESSION_COOKIE_NAME = "sessionid"                       # Session的cookie保存在浏览器上时的key,即:sessionid=随机字符串(默认)
    SESSION_COOKIE_PATH = "/"                               # Session的cookie保存的路径(默认)
    SESSION_COOKIE_DOMAIN = None                             # Session的cookie保存的域名(默认)
    SESSION_COOKIE_SECURE = False                            # 是否Https传输cookie(默认)
    SESSION_COOKIE_HTTPONLY = True                           # 是否Session的cookie只支持http传输(默认)
    SESSION_COOKIE_AGE = 1209600                             # Session的cookie失效日期(2周)(默认)
    SESSION_EXPIRE_AT_BROWSER_CLOSE = False                  # 是否关闭浏览器使得Session过期(默认)
    SESSION_SAVE_EVERY_REQUEST = False                       # 是否每次请求都保存Session,默认修改之后才保存(默认)

b. 使用
 
    def index(request):
        # 获取、设置、删除Session中数据
        request.session[‘k1‘]
        request.session.get(‘k1‘,None)
        request.session[‘k1‘] = 123
        request.session.setdefault(‘k1‘,123) # 存在则不设置
        del request.session[‘k1‘]
 
        # 所有 键、值、键值对
        request.session.keys()
        request.session.values()
        request.session.items()
        request.session.iterkeys()
        request.session.itervalues()
        request.session.iteritems()
 
 
        # 用户session的随机字符串
        request.session.session_key
 
        # 将所有Session失效日期小于当前日期的数据删除
        request.session.clear_expired()
 
        # 检查 用户session的随机字符串 在数据库中是否
        request.session.exists("session_key")
 
        # 删除当前用户的所有Session数据
        request.session.delete("session_key")
 
        request.session.set_expiry(value)
            * 如果value是个整数,session会在些秒数后失效。
            * 如果value是个datatime或timedelta,session就会在这个时间后失效。
            * 如果value是0,用户关闭浏览器session就会失效。
            * 如果value是None,session会依赖全局session失效策略。

session引擎

http://www.cnblogs.com/wupeiqi/articles/5246483.html

默认存在数据库(可以不设置)
a. 配置 settings.py
SESSION_ENGINE = ‘django.contrib.sessions.‘backends.db

2、缓存Session
 SESSION_ENGINE = ‘django.contrib.sessions.backends.cache‘  # 引擎
    SESSION_CACHE_ALIAS = ‘test‘    # 使用的缓存别名(默认内存缓存,也可以是memcache),此处别名依赖缓存的设置
    
CACHES = {
    ‘test‘ :{
        ‘BACKEND‘:‘django.core.cache.backends.memcached.MemcachedCache‘,
        ‘LOCATION‘:[
            ‘172.19.26.240:11211‘,
            172.19.26.241:11211,
        ]
    }
}
 
3、文件Session

a. 配置 settings.py
 
    SESSION_ENGINE = ‘django.contrib.sessions.backends.file‘    # 引擎
    SESSION_FILE_PATH = os.path.join(BASE_DIR,‘cache‘)
    
4、缓存+数据库Session

a. 配置 settings.py
 
    SESSION_ENGINE = ‘django.contrib.sessions.backends.cached_db‘        # 引擎


    
5、加密cookie Session

a. 配置 settings.py
     
    SESSION_ENGINE = ‘django.contrib.sessions.backends.signed_cookies‘   # 引擎

6,CSRF

POST提交和ajax提交

settings.py MIDDLEWARE 打开第四行

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>login</title>
</head>
<body>
    <form action="/login/" method="POST">
        {% csrf_token %}
        <input type="text" name="user"/>
        <input type="password" name="pwd"/>
        <input type="checkbox" name="rmb" value="1"/> 5秒免登录
        <input type="submit" value="提交"/>
        <input id="btn1" type="button" value="按钮" />
        <input id="btn2" type="button" value="按钮" />
    </form>

    <script src="/static/jquery-1.12.4.js"></script>
    <script src="/static/jquery.cookie.js"></script>
    <script>
        $(function(){
           ###发送csrf_token
            $.ajaxSetup({
                beforeSend: function(xhr,settings){
                    xhr.setRequestHeader(‘X-CSRFtoken‘, $.cookie(‘csrftoken‘));
                }
            });

            $(‘#btn1‘).click(function(){
                $.ajax({
                    url: ‘/login/‘,
                    type: "POST",
                    data: {‘user‘: ‘root‘,‘pwd‘:‘123‘},
                    // headers: {‘X-CSRFtoken‘: $.cookie(‘csrftoken‘)},
                    success:function(arg){

                    }
                })
            });
        })
    </script>
</body>
</html>
<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    {% csrf_token %}
  
    <input type="button" onclick="Do();"  value="Do it"/>
  
    <script src="/static/plugin/jquery/jquery-1.8.0.js"></script>
    <script src="/static/plugin/jquery/jquery.cookie.js"></script>
    <script type="text/javascript">
        var csrftoken = $.cookie(‘csrftoken‘);
  
        function csrfSafeMethod(method) {
             //只有post需要发送$.cookie(‘csrftoken‘);
            // these HTTP methods do not require CSRF protection
            return (/^(GET|HEAD|OPTIONS|TRACE)$/.test(method));
        }
        $.ajaxSetup({
            beforeSend: function(xhr, settings) {
                if (!csrfSafeMethod(settings.type) && !this.crossDomain) {
                    xhr.setRequestHeader("X-CSRFToken", csrftoken);
                }
            }
        });
        function Do(){
  
            $.ajax({
                url:"/app01/test/",
                data:{id:1},
                type:‘POST‘,
                success:function(data){
                    console.log(data);
                }
            });
  
        }
    </script>
</body>
</html>

7,中间件

指定函数使用中间件(默认全部)

跨站请求伪造

django为用户实现防止跨站请求伪造的功能,通过中间件 django.middleware.csrf.CsrfViewMiddleware 来完成。而对于django中设置防跨站请求伪造功能有分为全局和局部。

全局:

  中间件 django.middleware.csrf.CsrfViewMiddleware

局部:

@csrf_protect,为当前函数强制设置防跨站请求伪造功能,即便settings中没有设置全局中间件。
@csrf_exempt,取消当前函数防跨站请求伪造功能,即便settings中设置了全局中间件。
注:from django.views.decorators.csrf import csrf_exempt,csrf_protect

from django.views.decorators.csrf import csrf_exempt,csrf_protect
@csrf_protect
def index(request):
    if request.session.get(‘is_login‘,None):
        return render(request,‘index.html‘,{‘username‘:request.session[‘username‘]})
    else:
        return HttpResponse(‘gun‘)

中间件执行顺序

settings.py
from django.middleware.csrf import CsrfViewMiddleware
MIDDLEWARE = [
    ‘django.middleware.security.SecurityMiddleware‘,
    ‘django.contrib.sessions.middleware.SessionMiddleware‘,
    ‘django.middleware.common.CommonMiddleware‘,
    ‘django.middleware.csrf.CsrfViewMiddleware‘,
    ‘django.contrib.auth.middleware.AuthenticationMiddleware‘,
    ‘django.contrib.messages.middleware.MessageMiddleware‘,
    ‘django.middleware.clickjacking.XFrameOptionsMiddleware‘,
    ‘Middle.m1.Row1‘,
    ‘Middle.m1.Row2‘,
    ‘Middle.m1.Row3‘,
]

m1.py
from django.utils.deprecation import MiddlewareMixin

class Row1(MiddlewareMixin):
    #1
    def process_request(self,request):
        print(‘王森‘)
    #7
    def process_view(self, request, view_func, view_func_args, view_func_kwargs):
        print(‘张欣彤‘)
    #6
    def process_response(self, request, response):
        print(‘扛把子‘)
        return response

from django.shortcuts import HttpResponse
class Row2(MiddlewareMixin):
    #2
    def process_request(self,request):
        print(‘程毅强‘)
        # return HttpResponse(‘走‘)

    # 8
    def process_view(self, request, view_func, view_func_args, view_func_kwargs):
        print(‘张需要‘)

    #5
    def process_response(self, request, response):
        print(‘侯雅凡‘)
        return response

class Row3(MiddlewareMixin):
    #3
    def process_request(self,request):
        print(‘刘东‘)
    #9
    def process_view(self, request, view_func, view_func_args, view_func_kwargs):
        print(‘邵林‘)
    #4
    def process_response(self, request, response):
        print(‘连之泪‘)
        return response

    def process_exception(self, request, exception):
        if isinstance(exception,ValueError):
            return HttpResponse(‘出现异常》。。‘)

    def process_template_response(self,request,response):
        # 如果Views中的函数返回的对象中,具有render方法
        print(‘-----------------------‘)
        return response

8,缓存

由于Django是动态网站,所有每次请求均会去数据进行相应的操作,当程序访问量大时,耗时必然会更加明显,最简单解决方式是使用:缓存,缓存将一个某个views的返回值保存至内存或者memcache中,5分钟内再有人来访问时,则不再去执行view中的操作,而是直接从内存或者Redis中之前缓存的内容拿到,并返回。

 

Django中提供了6种缓存方式:

# 此为开始调试用,实际内部不做任何操作
    # 配置:
        CACHES = {
            ‘default‘: {
                ‘BACKEND‘: ‘django.core.cache.backends.dummy.DummyCache‘,     # 引擎
                ‘TIMEOUT‘: 300,                                               # 缓存超时时间(默认300,None表示永不过期,0表示立即过期)
                ‘OPTIONS‘:{
                    ‘MAX_ENTRIES‘: 300,                                       # 最大缓存个数(默认300)
                    ‘CULL_FREQUENCY‘: 3,                                      # 缓存到达最大个数之后,剔除缓存个数的比例,即:1/CULL_FREQUENCY(默认3)
                },
                ‘KEY_PREFIX‘: ‘‘,                                             # 缓存key的前缀(默认空)
                ‘VERSION‘: 1,                                                 # 缓存key的版本(默认1)
                ‘KEY_FUNCTION‘ 函数名                                          # 生成key的函数(默认函数会生成为:【前缀:版本:key】)
            }
        }


    # 自定义key
    def default_key_func(key, key_prefix, version):
        """
        Default function to generate keys.

        Constructs the key used by all other methods. By default it prepends
        the `key_prefix‘. KEY_FUNCTION can be used to specify an alternate
        function with custom key making behavior.
        """
        return ‘%s:%s:%s‘ % (key_prefix, version, key)

    def get_key_func(key_func):
        """
        Function to decide which key function to use.

        Defaults to ``default_key_func``.
        """
        if key_func is not None:
            if callable(key_func):
                return key_func
            else:
                return import_string(key_func)
        return default_key_func

1,配置

a,开发调试

开发调试
内存
文件
数据库
Memcache缓存(python-memcached模块)
Memcache缓存(pylibmc模块)

b,内存

# 此缓存将内容保存至内存的变量中
    # 配置:
        CACHES = {
            ‘default‘: {
                ‘BACKEND‘: ‘django.core.cache.backends.locmem.LocMemCache‘,
                ‘LOCATION‘: ‘unique-snowflake‘,
            }
        }

    # 注:其他配置同开发调试版本

c,文件

# 此缓存将内容保存至文件
    # 配置:

        CACHES = {
            ‘default‘: {
                ‘BACKEND‘: ‘django.core.cache.backends.filebased.FileBasedCache‘,
                ‘LOCATION‘: ‘/var/tmp/django_cache‘,
            }
        }
    # 注:其他配置同开发调试版本

urls.py

urlpatterns = [
    url(r‘^cache/$‘,views.cache),
]

views.py

@cache_page(10)
def cache(request):
    import time
    ctime = time.time()
    return render(request,‘cache.html‘,{‘ctime‘:ctime})
    

def cache(request):
    import time
    ctime = time.time()
    return render(request,‘cache.html‘,{‘ctime‘:ctime})

cache.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
     <h1>{{ ctime }}</h1>
     <h1>{{ ctime }}</h1>
</body>
</html>

#########
{% load cache %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
     <h1>{{ ctime }}</h1>
     <h1>{{ ctime }}</h1>
        {% cache 10 c1 %}
           <h1>{{ ctime }}</h1>
        {% endcache %}
</body>
</html>

settings.py

CACHES = {
    ‘default‘:{
        ‘BACKEND‘:‘django.core.cache.backends.filebased.FileBasedCache‘,
        ‘LOCATION‘: os.path.join(BASE_DIR,‘cache‘)
    }
}

d、数据库

# 此缓存将内容保存至数据库

    # 配置:
        CACHES = {
            ‘default‘: {
                ‘BACKEND‘: ‘django.core.cache.backends.db.DatabaseCache‘,
                ‘LOCATION‘: ‘my_cache_table‘, # 数据库表
            }
        }

    # 注:执行创建表命令 python manage.py createcachetable

e、Memcache缓存(python-memcached模块)

# 此缓存使用python-memcached模块连接memcache

    CACHES = {
        ‘default‘: {
            ‘BACKEND‘: ‘django.core.cache.backends.memcached.MemcachedCache‘,
            ‘LOCATION‘: ‘127.0.0.1:11211‘,
        }
    }

    CACHES = {
        ‘default‘: {
            ‘BACKEND‘: ‘django.core.cache.backends.memcached.MemcachedCache‘,
            ‘LOCATION‘: ‘unix:/tmp/memcached.sock‘,
        }
    }   

    CACHES = {
        ‘default‘: {
            ‘BACKEND‘: ‘django.core.cache.backends.memcached.MemcachedCache‘,
            ‘LOCATION‘: [
                ‘172.19.26.240:11211‘,
                ‘172.19.26.242:11211‘,
            ]
        }
    }

f、Memcache缓存(pylibmc模块)

    # 此缓存使用pylibmc模块连接memcache
        
        CACHES = {
            ‘default‘: {
                ‘BACKEND‘: ‘django.core.cache.backends.memcached.PyLibMCCache‘,
                ‘LOCATION‘: ‘127.0.0.1:11211‘,
            }
        }
    
        CACHES = {
            ‘default‘: {
                ‘BACKEND‘: ‘django.core.cache.backends.memcached.PyLibMCCache‘,
                ‘LOCATION‘: ‘/tmp/memcached.sock‘,
            }
        }   
    
        CACHES = {
            ‘default‘: {
                ‘BACKEND‘: ‘django.core.cache.backends.memcached.PyLibMCCache‘,
                ‘LOCATION‘: [
                    ‘172.19.26.240:11211‘,
                    ‘172.19.26.242:11211‘,
                ]
            }
        }

g. Redis缓存(依赖:pip3 install django-redis) 

    CACHES = {
        "default": {
            "BACKEND": "django_redis.cache.RedisCache",
            "LOCATION": "redis://127.0.0.1:6379",
            "OPTIONS": {
                "CLIENT_CLASS": "django_redis.client.DefaultClient",
                "CONNECTION_POOL_KWARGS": {"max_connections": 100}
                # "PASSWORD": "密码",
            }
        }
    }

    from django_redis import get_redis_connection
    conn = get_redis_connection("default")

2、应用 

    使用中间件,经过一系列的认证等操作,如果内容在缓存中存在,则使用FetchFromCacheMiddleware获取内容并返回给用户,当返回给用户之前,判断缓存中是否已经存在,如果不存在则UpdateCacheMiddleware会将缓存保存至缓存,从而实现全站缓存
    
        MIDDLEWARE = [
            ‘django.middleware.cache.UpdateCacheMiddleware‘,
            # 其他中间件...
            ‘django.middleware.cache.FetchFromCacheMiddleware‘,
        ]
    
        CACHE_MIDDLEWARE_ALIAS = ""
        CACHE_MIDDLEWARE_SECONDS = ""
        CACHE_MIDDLEWARE_KEY_PREFIX = ""
     
     
        MIDDLEWARE = [
        # ‘django.middleware.cache.UpdateCacheMiddleware‘,
        ‘django.middleware.security.SecurityMiddleware‘,
        ‘django.contrib.sessions.middleware.SessionMiddleware‘,
        ‘django.middleware.common.CommonMiddleware‘,
        ‘django.middleware.csrf.CsrfViewMiddleware‘,
        ‘django.contrib.auth.middleware.AuthenticationMiddleware‘,
        ‘django.contrib.messages.middleware.MessageMiddleware‘,
        ‘django.middleware.clickjacking.XFrameOptionsMiddleware‘,
        # ‘Middle.m1.Row1‘,
        # ‘Middle.m1.Row2‘,
        # ‘Middle.m1.Row3‘,
        # ‘django.middleware.cache.FetchFromCacheMiddleware‘,
    
    ]

g. Redis缓存(依赖:pip3 install django-redis)

CACHES = {
    "default": {
        "BACKEND": "django_redis.cache.RedisCache",
        "LOCATION": "redis://127.0.0.1:6379",
        "OPTIONS": {
            "CLIENT_CLASS": "django_redis.client.DefaultClient",
            "CONNECTION_POOL_KWARGS": {"max_connections": 100}
            # "PASSWORD": "密码",
        }
    }
}


from django_redis import get_redis_connection
conn = get_redis_connection("default")

2,应用

使用中间件,经过一系列的认证等操作,如果内容在缓存中存在,则使用FetchFromCacheMiddleware获取内容并返回给用户,当返回给用户之前,判断缓存中是否已经存在,如果不存在则UpdateCacheMiddleware会将缓存保存至缓存,从而实现全站缓存。

  MIDDLEWARE = [
        ‘django.middleware.cache.UpdateCacheMiddleware‘,
        # 其他中间件...
        ‘django.middleware.cache.FetchFromCacheMiddleware‘,
    ]

    CACHE_MIDDLEWARE_ALIAS = ""
    CACHE_MIDDLEWARE_SECONDS = ""
    CACHE_MIDDLEWARE_KEY_PREFIX = ""
 
 
    MIDDLEWARE = [
    # ‘django.middleware.cache.UpdateCacheMiddleware‘,
    ‘django.middleware.security.SecurityMiddleware‘,
    ‘django.contrib.sessions.middleware.SessionMiddleware‘,
    ‘django.middleware.common.CommonMiddleware‘,
    ‘django.middleware.csrf.CsrfViewMiddleware‘,
    ‘django.contrib.auth.middleware.AuthenticationMiddleware‘,
    ‘django.contrib.messages.middleware.MessageMiddleware‘,
    ‘django.middleware.clickjacking.XFrameOptionsMiddleware‘,
    # ‘Middle.m1.Row1‘,
    # ‘Middle.m1.Row2‘,
    # ‘Middle.m1.Row3‘,
    # ‘django.middleware.cache.FetchFromCacheMiddleware‘,

]

b. 单独视图缓存

方式一:
        from django.views.decorators.cache import cache_page

        @cache_page(60 * 15)
        def my_view(request):
            ...

    方式二:
        from django.views.decorators.cache import cache_page

        urlpatterns = [
            url(r‘^foo/([0-9]{1,2})/$‘, cache_page(60 * 15)(my_view)),
        ]

c、局部视图使用

a. 引入TemplateTag

        {% load cache %}

    b. 使用缓存

        {% cache 5000 缓存key %}
            缓存内容
        {% endcache %}

9,信号

Django中提供了“信号调度”,用于在框架执行操作时解耦。通俗来讲,就是一些动作发生的时候,信号允许特定的发送者去提醒一些接受者。

1、Django内置信号

Model signals
    pre_init                    # django的modal执行其构造方法前,自动触发
    post_init                   # django的modal执行其构造方法后,自动触发
    pre_save                    # django的modal对象保存前,自动触发
    post_save                   # django的modal对象保存后,自动触发
    pre_delete                  # django的modal对象删除前,自动触发
    post_delete                 # django的modal对象删除后,自动触发
    m2m_changed                 # django的modal中使用m2m字段操作第三张表(add,remove,clear)前后,自动触发
    class_prepared              # 程序启动时,检测已注册的app中modal类,对于每一个类,自动触发
Management signals
    pre_migrate                 # 执行migrate命令前,自动触发
    post_migrate                # 执行migrate命令后,自动触发
Request/response signals
    request_started             # 请求到来前,自动触发
    request_finished            # 请求结束后,自动触发
    got_request_exception       # 请求异常后,自动触发
Test signals
    setting_changed             # 使用test测试修改配置文件时,自动触发
    template_rendered           # 使用test测试渲染模板时,自动触发
Database Wrappers
    connection_created          # 创建数据库连接时,自动触发

对于Django内置的信号,仅需注册指定信号,当程序执行相应操作时,自动触发注册函数:

###__init__.py
import sg

###sp.py
from django.core.signals import request_finished
    from django.core.signals import request_started
    from django.core.signals import got_request_exception

    from django.db.models.signals import class_prepared
    from django.db.models.signals import pre_init, post_init
    from django.db.models.signals import pre_save, post_save
    from django.db.models.signals import pre_delete, post_delete
    from django.db.models.signals import m2m_changed
    from django.db.models.signals import pre_migrate, post_migrate

    from django.test.signals import setting_changed
    from django.test.signals import template_rendered

    from django.db.backends.signals import connection_created


    def callback(sender, **kwargs):
        print("xxoo_callback")
        print(sender,kwargs)

    pre_init.connect(callback)
    # pre_init指上述导入的内容
from django.core.signals import request_finished
from django.dispatch import receiver

@receiver(request_finished)
def my_callback(sender, **kwargs):
    print("Request finished!")

2、自定义信号

a. 定义信号

import django.dispatch
pizza_done = django.dispatch.Signal(providing_args=["toppings", "size"])

b. 注册信号

def callback(sender, **kwargs):
    print("callback")
    print(sender,kwargs)
 
pizza_done.connect(callback)

c. 触发信号

from 路径 import pizza_done
 
pizza_done.send(sender=‘seven‘,toppings=123, size=456)

由于内置信号的触发者已经集成到Django中,所以其会自动调用,而对于自定义信号则需要开发者在任意位置触发。

url(r‘^signal/$‘, views.signal),
  
###__init__.py
import sg

###sp.py
  
  def signal(reuqest):
    from app01 import models

    obj = models.UserInf(user=‘root‘)
    print(‘end‘)
    obj.save()

    obj = models.UserInf(user=‘root‘)
    obj.save()

    obj = models.UserInf(user=‘root‘)
    obj.save()

    触发
    from sg import pizza_done

    pizza_done.send(sender="asdfasdf",toppings=123, size=456)

    return HttpResponse(‘ok‘)
    
    
    
###sg.py
from django.core.signals import request_finished
from django.core.signals import request_started
from django.core.signals import got_request_exception

from django.db.models.signals import class_prepared
from django.db.models.signals import pre_init, post_init
from django.db.models.signals import pre_save, post_save
from django.db.models.signals import pre_delete, post_delete
from django.db.models.signals import m2m_changed
from django.db.models.signals import pre_migrate, post_migrate

from django.test.signals import setting_changed
from django.test.signals import template_rendered

from django.db.backends.signals import connection_created



自定义信号
import django.dispatch
pizza_done = django.dispatch.Signal(providing_args=["toppings", "size"])
创建
def callback(sender, **kwargs):
    print("callback")
    print(sender,kwargs)
    
注册
pizza_done.connect(callback)


http://www.cnblogs.com/wupeiqi/articles/5246483.html

10,Form

url(r‘^fm/$‘,views.fm),

from django import forms
from django.forms import widgets
from django.forms import fields
class FM(forms.Form):
    # 字段本身只做验证
    #自定义字段
    user = fields.CharField(
        error_messages={‘required‘: ‘用户名不能为空.‘},
        #自定义插件
        widget=widgets.Textarea(attrs={‘class‘: ‘c1‘}),
        label=‘用户名‘,
        )
    pwd = fields.CharField(
        max_length=12,
        min_length=6,
        error_messages={‘required‘:‘密码不能为空.‘,‘min_length‘:‘密码长度不能小于6‘,‘max_length‘:‘密码长度不能大于12‘},
        widget=widgets.PasswordInput(attrs={‘class‘: ‘c2‘})
    )
    email = fields.EmailField(error_messages={‘required‘:‘邮箱不能为空‘,‘invalid‘:‘邮箱格式错误‘})
    #上传文件
    f = fields.FileField()
    # p = fields.FilePathField(path=‘app01‘)
    city1 = fields.ChoiceField(
        choices=[(0,‘上海‘),(1,‘广州‘),(2,‘东莞‘)]
    )
    city2 = fields.MultipleChoiceField(
        choices=[(0,‘上海‘),(1,‘广州‘),(2,‘东莞‘)]
    )

from app01 import models
def fm(request):
    if request.method == "GET":
        # 从数据库中把数据获取到
        dic = {
            "user": ‘r1‘,
            ‘pwd‘: ‘123123‘,
            ‘email‘: ‘sdfsd‘,
            ‘city1‘:1,
            ‘city2‘:[1,2]
        }
        obj = FM(initial=dic)
        return render(request,‘fm.html‘,{‘obj‘:obj})
    elif request.method == "POST":
        # 获取用户所有数据
        # 每条数据请求的验证
        # 成功 获取所有的正确的信息
        # 失败 显示错误信息
        obj = FM(request.POST)
        r1 = obj.js_valid()
        if r1:
            # obj.cleaned_data
            models.UserInf.objects.create(**obj.cleaned_data)
        else:
            # ErrorDict
            # print(obj.errors.as_json())
            # print(obj.errors[‘user‘][0])
            return render(request,‘fm.html‘,{‘obj‘:obj})
        return render(request,‘fm.html‘)

fm.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/fm/" method="POST">
        {% csrf_token %}
        <p>{{ obj.user.label }} {{ obj.user }} {{ obj.errors.user.0 }}</p>
        <p>{{ obj.pwd }} {{ obj.errors.pwd.0 }}</p>
        <p>{{ obj.email }} {{ obj.errors.email.0 }}</p>
        <p>{{ obj.f }} {{ obj.errors.f.0 }}</p>
        {{ obj.city1 }}
        {{ obj.city2 }}
        <input type="submit" value="提交"/>
    </form>
</body>
</html>

创建Form类时,主要涉及到 【字段】 和 【插件】,字段用于对用户请求数据的验证,插件用于自动生成HTML;

1、Django内置字段如下:

Field
    required=True,               是否允许为空
    widget=None,                 HTML插件
    label=None,                  用于生成Label标签或显示内容
    initial=None,                初始值
    help_text=‘‘,                帮助信息(在标签旁边显示)
    error_messages=None,         错误信息 {‘required‘: ‘不能为空‘, ‘invalid‘: ‘格式错误‘}
    show_hidden_initial=False,   是否在当前插件后面再加一个隐藏的且具有默认值的插件(可用于检验两次输入是否一直)
    validators=[],               自定义验证规则
    localize=False,              是否支持本地化
    disabled=False,              是否可以编辑
    label_suffix=None            Label内容后缀
 
 
CharField(Field)
    max_length=None,             最大长度
    min_length=None,             最小长度
    strip=True                   是否移除用户输入空白
 
IntegerField(Field)
    max_value=None,              最大值
    min_value=None,              最小值
 
FloatField(IntegerField)
    ...
 
DecimalField(IntegerField)
    max_value=None,              最大值
    min_value=None,              最小值
    max_digits=None,             总长度
    decimal_places=None,         小数位长度
 
BaseTemporalField(Field)
    input_formats=None          时间格式化   
 
DateField(BaseTemporalField)    格式:2015-09-01
TimeField(BaseTemporalField)    格式:11:12
DateTimeField(BaseTemporalField)格式:2015-09-01 11:12
 
DurationField(Field)            时间间隔:%d %H:%M:%S.%f
    ...
 
RegexField(CharField)
    regex,                      自定制正则表达式
    max_length=None,            最大长度
    min_length=None,            最小长度
    error_message=None,         忽略,错误信息使用 error_messages={‘invalid‘: ‘...‘}
 
EmailField(CharField)      
    ...
 
FileField(Field)
    allow_empty_file=False     是否允许空文件
 
ImageField(FileField)      
    ...
    注:需要PIL模块,pip3 install Pillow
    以上两个字典使用时,需要注意两点:
        - form表单中 enctype="multipart/form-data"
        - view函数中 obj = MyForm(request.POST, request.FILES)
 
URLField(Field)
    ...
 
 
BooleanField(Field)  
    ...
 
NullBooleanField(BooleanField)
    ...
 
ChoiceField(Field)
    ...
    choices=(),                选项,如:choices = ((0,‘上海‘),(1,‘北京‘),)
    required=True,             是否必填
    widget=None,               插件,默认select插件
    label=None,                Label内容
    initial=None,              初始值
    help_text=‘‘,              帮助提示
 
 
ModelChoiceField(ChoiceField)
    ...                        django.forms.models.ModelChoiceField
    queryset,                  # 查询数据库中的数据
    empty_label="---------",   # 默认空显示内容
    to_field_name=None,        # HTML中value的值对应的字段
    limit_choices_to=None      # ModelForm中对queryset二次筛选
     
ModelMultipleChoiceField(ModelChoiceField)
    ...                        django.forms.models.ModelMultipleChoiceField
 
 
     
TypedChoiceField(ChoiceField)
    coerce = lambda val: val   对选中的值进行一次转换
    empty_value= ‘‘            空值的默认值
 
MultipleChoiceField(ChoiceField)
    ...
 
TypedMultipleChoiceField(MultipleChoiceField)
    coerce = lambda val: val   对选中的每一个值进行一次转换
    empty_value= ‘‘            空值的默认值
 
ComboField(Field)
    fields=()                  使用多个验证,如下:即验证最大长度20,又验证邮箱格式
                               fields.ComboField(fields=[fields.CharField(max_length=20), fields.EmailField(),])
 
MultiValueField(Field)
    PS: 抽象类,子类中可以实现聚合多个字典去匹配一个值,要配合MultiWidget使用
 
SplitDateTimeField(MultiValueField)
    input_date_formats=None,   格式列表:[‘%Y--%m--%d‘, ‘%m%d/%Y‘, ‘%m/%d/%y‘]
    input_time_formats=None    格式列表:[‘%H:%M:%S‘, ‘%H:%M:%S.%f‘, ‘%H:%M‘]
 
FilePathField(ChoiceField)     文件选项,目录下文件显示在页面中
    path,                      文件夹路径
    match=None,                正则匹配
    recursive=False,           递归下面的文件夹
    allow_files=True,          允许文件
    allow_folders=False,       允许文件夹
    required=True,
    widget=None,
    label=None,
    initial=None,
    help_text=‘‘
 
GenericIPAddressField
    protocol=‘both‘,           both,ipv4,ipv6支持的IP格式
    unpack_ipv4=False          解析ipv4地址,如果是::ffff:192.0.2.1时候,可解析为192.0.2.1, PS:protocol必须为both才能启用
 
SlugField(CharField)           数字,字母,下划线,减号(连字符)
    ...
 
UUIDField(CharField)           uuid类型

注:UUID是根据MAC以及当前时间等创建的不重复的随机字符串

>>> import uuid

    # make a UUID based on the host ID and current time
    >>> uuid.uuid1()    # doctest: +SKIP
    UUID(‘a8098c1a-f86e-11da-bd1a-00112444be1e‘)

    # make a UUID using an MD5 hash of a namespace UUID and a name
    >>> uuid.uuid3(uuid.NAMESPACE_DNS, ‘python.org‘)
    UUID(‘6fa459ea-ee8a-3ca4-894e-db77e160355e‘)

    # make a random UUID
    >>> uuid.uuid4()    # doctest: +SKIP
    UUID(‘16fd2706-8baf-433b-82eb-8c7fada847da‘)

    # make a UUID using a SHA-1 hash of a namespace UUID and a name
    >>> uuid.uuid5(uuid.NAMESPACE_DNS, ‘python.org‘)
    UUID(‘886313e1-3b8a-5372-9b90-0c9aee199e5d‘)

    # make a UUID from a string of hex digits (braces and hyphens ignored)
    >>> x = uuid.UUID(‘{00010203-0405-0607-0809-0a0b0c0d0e0f}‘)

    # convert a UUID to a string of hex digits in standard form
    >>> str(x)
    ‘00010203-0405-0607-0809-0a0b0c0d0e0f‘

    # get the raw 16 bytes of the UUID
    >>> x.bytes
    b‘x00x01x02x03x04x05x06x07x08	
x0bx0c
x0ex0f‘

    # make a UUID from a 16-byte string
    >>> uuid.UUID(bytes=x.bytes)
    UUID(‘00010203-0405-0607-0809-0a0b0c0d0e0f‘)

2、Django内置插件:

TextInput(Input)
NumberInput(TextInput)
EmailInput(TextInput)
URLInput(TextInput)
PasswordInput(TextInput)
HiddenInput(TextInput)
Textarea(Widget)
DateInput(DateTimeBaseInput)
DateTimeInput(DateTimeBaseInput)
TimeInput(DateTimeBaseInput)
CheckboxInput
Select
NullBooleanSelect
SelectMultiple
Radioselect
CheckboxSelectMultiple
FileInput
ClearableFileInput
MultipleHiddenInput
SplitDateTimeWidget
SplitHiddenDateTimeWidget
SelectDateWidget

 

常用插件

 单radio,值为字符串
 user = fields.CharField(
     initial=2,
     widget=widgets.RadioSelect(choices=((1,‘上海‘),(2,‘北京‘),))
 )
 
 单radio,值为字符串
 user = fields.ChoiceField(
     choices=((1, ‘上海‘), (2, ‘北京‘),),
     initial=2,
     widget=widgets.RadioSelect
 )
 
 单select,值为字符串
 user = fields.CharField(
     initial=2,
     widget=widgets.Select(choices=((1,‘上海‘),(2,‘北京‘),))
 )
 
 单select,值为字符串
 user = fields.ChoiceField(
     choices=((1, ‘上海‘), (2, ‘北京‘),),
     initial=2,
     widget=widgets.Select
 )
 
 多选select,值为列表
 user = fields.MultipleChoiceField(
     choices=((1,‘上海‘),(2,‘北京‘),),
     initial=[1,],
     widget=widgets.SelectMultiple
 )
 
 
 单checkbox
 user = fields.CharField(
     widget=widgets.CheckboxInput()
 )
 
 
 多选checkbox,值为列表
 user = fields.MultipleChoiceField(
     initial=[2, ],
     choices=((1, ‘上海‘), (2, ‘北京‘),),
     widget=widgets.CheckboxSelectMultiple
 )

在使用选择标签时,需要注意choices的选项可以从数据库中获取,但是由于是静态字段 获取的值无法实时更新,那么需要自定义构造方法从而达到此目的。

 

自定义验证规则

方式一:

from django.forms import Form
from django.forms import widgets
from django.forms import fields
from django.core.validators import RegexValidator
 
class MyForm(Form):
    user = fields.CharField(
        validators=[RegexValidator(r‘^[0-9]+$‘, ‘请输入数字‘), RegexValidator(r‘^159[0-9]+$‘, ‘数字必须以159开头‘)],
    )   

方式二:

import re
from django.forms import Form
from django.forms import widgets
from django.forms import fields
from django.core.exceptions import ValidationError
 
 
# 自定义验证规则
def mobile_validate(value):
    mobile_re = re.compile(r‘^(13[0-9]|15[012356789]|17[678]|18[0-9]|14[57])[0-9]{8}$‘)
    if not mobile_re.match(value):
        raise ValidationError(‘手机号码格式错误‘)
 
 
class PublishForm(Form):
 
 
    title = fields.CharField(max_length=20,
                            min_length=5,
                            error_messages={‘required‘: ‘标题不能为空‘,
                                            ‘min_length‘: ‘标题最少为5个字符‘,
                                            ‘max_length‘: ‘标题最多为20个字符‘},
                            widget=widgets.TextInput(attrs={‘class‘: "form-control",
                                                          ‘placeholder‘: ‘标题5-20个字符‘}))
 
 
    # 使用自定义验证规则
    phone = fields.CharField(validators=[mobile_validate, ],
                            error_messages={‘required‘: ‘手机不能为空‘},
                            widget=widgets.TextInput(attrs={‘class‘: "form-control",
                                                          ‘placeholder‘: u‘手机号码‘}))
 
    email = fields.EmailField(required=False,
                            error_messages={‘required‘: u‘邮箱不能为空‘,‘invalid‘: u‘邮箱格式错误‘},
                            widget=widgets.TextInput(attrs={‘class‘: "form-control", ‘placeholder‘: u‘邮箱‘}))

方法三:自定义方法

from django import forms
    from django.forms import fields
    from django.forms import widgets
    from django.core.exceptions import ValidationError
    from django.core.validators import RegexValidator
 
    class FInfo(forms.Form):
        username = fields.CharField(max_length=5,
                                    validators=[RegexValidator(r‘^[0-9]+$‘, ‘Enter a valid extension.‘, ‘invalid‘)], )
        email = fields.EmailField()
 
        def clean_username(self):
            """
            Form中字段中定义的格式匹配完之后,执行此方法进行验证
            :return:
            """
            value = self.cleaned_data[‘username‘]
            if "666" in value:
                raise ValidationError(‘666已经被玩烂了...‘, ‘invalid‘)
            return value

方式四:同时生成多个标签进行验证

from django.forms import Form
from django.forms import widgets
from django.forms import fields
 
from django.core.validators import RegexValidator
 
 
############## 自定义字段 ##############
class PhoneField(fields.MultiValueField):
    def __init__(self, *args, **kwargs):
        # Define one message for all fields.
        error_messages = {
            ‘incomplete‘: ‘Enter a country calling code and a phone number.‘,
        }
        # Or define a different message for each field.
        f = (
            fields.CharField(
                error_messages={‘incomplete‘: ‘Enter a country calling code.‘},
                validators=[
                    RegexValidator(r‘^[0-9]+$‘, ‘Enter a valid country calling code.‘),
                ],
            ),
            fields.CharField(
                error_messages={‘incomplete‘: ‘Enter a phone number.‘},
                validators=[RegexValidator(r‘^[0-9]+$‘, ‘Enter a valid phone number.‘)],
            ),
            fields.CharField(
                validators=[RegexValidator(r‘^[0-9]+$‘, ‘Enter a valid extension.‘)],
                required=False,
            ),
        )
        super(PhoneField, self).__init__(error_messages=error_messages, fields=f, require_all_fields=False, *args,
                                         **kwargs)
 
    def compress(self, data_list):
        """
        当用户验证都通过后,该值返回给用户
        :param data_list:
        :return:
        """
        return data_list
 
############## 自定义插件 ##############
class SplitPhoneWidget(widgets.MultiWidget):
    def __init__(self):
        ws = (
            widgets.TextInput(),
            widgets.TextInput(),
            widgets.TextInput(),
        )
        super(SplitPhoneWidget, self).__init__(ws)
 
    def decompress(self, value):
        """
        处理初始值,当初始值initial不是列表时,调用该方法
        :param value:
        :return:
        """
        if value:
            return value.split(‘,‘)
        return [None, None, None]
初始化数据

http://www.cnblogs.com/wupeiqi/articles/6144178.html

初始化

在Web应用程序中开发编写功能时,时常用到获取数据库中的数据并将值初始化在HTML中的标签上。

1、Form

from django.forms import Form
from django.forms import widgets
from django.forms import fields
from django.core.validators import RegexValidator
 
 
class MyForm(Form):
    user = fields.CharField()
 
    city = fields.ChoiceField(
        choices=((1, ‘上海‘), (2, ‘北京‘),),
        widget=widgets.Select
    )

2、Views

from django.shortcuts import render, redirect
from .forms import MyForm
 
 
def index(request):
    if request.method == "GET":
        values = {‘user‘: ‘root‘, ‘city‘: 2}
        obj = MyForm(values)
 
        return render(request, ‘index.html‘, {‘form‘: obj})
    elif request.method == "POST":
        return redirect(‘http://www.google.com‘)
    else:
        return redirect(‘http://www.google.com‘)

3、HTML

<form method="POST" enctype="multipart/form-data">
    {% csrf_token %}
    <p>{{ form.user }} {{ form.user.errors }}</p>
    <p>{{ form.city }} {{ form.city.errors }}</p>
 
    <input type="submit"/>
</form>

  

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