Django学习笔记(四)

前言

上两篇我们学习了MVT和Models进行数据库的操作，这一篇我们还是以实例来讲解，主要学习使用Django 编写一个 注册、登录、验证码的例子。

• 我们将学到如下知识：
  • Django forms表单样式排版
  • 验证码实现的机制 cookies session 设置
  • Django request对象传值
  • Django 自带的用户登录判断

例子

快速上手还是多动手敲打键盘编写代码，多动手实现。直接上学例子学习，主要是先建立Django实现功能的思想，里面的细枝末节可以搜索一下相关的资料进行补充巩固学习。
这里介绍两种编写的方法，一种是自己设计用户登录注销管理cookies和session。另一种就是使用Django自带判断登录 注销等

例子四（1）

验证码的部分参考https://strcpy.me/index.php/archives/176/
每次获取的验证码都需要把上次生成的验证码消除。
准备工作
以后准备工作都是相同的，设置方面也是一直的。

$python-admin startproject project  #创建项目
$python manage.py startapp blog     #创建应用
#设置数据库、应用加载、模板文件路径
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'django-test',
        'USER': 'root',
        'PASSWORD': 'seck@root...',
        'HOST': '127.0.0.1',
        'PORT': '3306',
    }
}
INSTALLED_APPS = (
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'blog',
)
TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR, 'templates')],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

项目的文件结构如图

首先编写models.py 创建数据库表结构

#!/usr/bin/env python
#-*- coding:utf-8 _*-
"""
author:seck
time: 2018/01/28
"""
from django import forms
from .views import *
class UserRegisterForm(forms.Form):
    username = forms.CharField(label='用户名',max_length=50)
    password = forms.CharField(label='密码',widget=forms.PasswordInput())
    email = forms.EmailField(label='邮箱')
    # captcha1=captcha()
class UserLoginForm(forms.Form):
    username = forms.CharField(label='用户名', max_length=50)
    password = forms.CharField(label='密码', widget=forms.PasswordInput())

编写forms.py

• 创建类，继承form.Form
• 页面根据类的对象自动创建html标签
• 提交，request.POST
• 封装到类的对象里，obj=UserInfo(request.POST)
• 用户输入是否合法
• obj.is_valid()
• 全部合法，获取全部内容
• obj.clean()
• 只有有不合法
• obj.errors

  #!/usr/bin/env python
  #-*- coding:utf-8 _*-
  """
  author:seck
  time: 2018/01/28
  """
  from django import forms
  from .views import *
  class UserRegisterForm(forms.Form):
      username = forms.CharField(
          required=True,
          error_messages={'required':'用户名不能为空'},
          label='用户名',max_length=50,widget=forms.TextInput(attrs={'placeholder': 'Username','class':'username11'}))
      password = forms.CharField(label='密码',widget=forms.PasswordInput())
      email = forms.EmailField(label='邮箱')
      # captcha1=captcha()
  class UserLoginForm(forms.Form):
      username = forms.CharField(required=True,
          error_messages={'required':'用户名不能为空'},label='用户名', max_length=50)
      password = forms.CharField(label='密码', widget=forms.PasswordInput())

attrs属性是定义在html中用户登录框的css属性名称，error_messages 确认输入的是否规范返回错误的信息比如required=True 如果没有填入用户名，就会显示“用户名不能为空”
细节参考http://www.cnblogs.com/zhaijunming5/category/892772.html
http://www.cnblogs.com/yangmv/p/5327477.html

编写views.py进行控制数据传送
关键点的信息就是使用session控制验证码的验证。

#coding:utf-8
from django.shortcuts import render
from django.http import HttpResponse,HttpResponseRedirect ,request
from captcha import *
from .forms import *
from .models import *
# Create your views here.
#首先显示
def index(request):
    data=[]
    try:
        if request.session['username']:
            seesion=request.session['username']
            print seesion
            if seesion:
                data.append(seesion)
                print "login success!"
    except Exception , e:
        print (e)
        data.append('no login')
    title="seck"
    print request.COOKIES
    # return HttpResponse("<img id='verifycode' src='/captcha/' alt='CheckCode'/>")
    return render(request,'blog/index.html',{'title':title,'data':data},)
#验证码调用
def captcha(request):
    Cap = Captcha(request)
    Code =Cap.display()
    return Code
#注册
def register(request):
    if request.method == 'POST':
        userform =UserRegisterForm(request.POST)
        cap = request.POST.get('cap')
        ca = Captcha(request)
        if userform.is_valid():
            username = userform.cleaned_data['username']
            password = userform.cleaned_data['password']
            email = userform.cleaned_data['email']
            if ca.check(cap):
                print "The code true"
            else:
                print "The code error!"
                return HttpResponse("验证码不正确,请刷新后重新输入！")
            if User.objects.filter(username=username):
                print "The user exits"
                return HttpResponse("用户名重复！")
            else:
                User.objects.create(username=username, password=password, email=email).save()
                return HttpResponse('register success!')
    else:
        userform = UserRegisterForm()
    return render(request,'blog/register.html',{'userform':userform,})
def login(request):
    if request.method == "POST":
        userform = UserLoginForm(request.POST)
        print userform.errors.get('username')
        if userform.is_valid():
            username = userform.cleaned_data['username']
            password = userform.cleaned_data['password']
            user= User.objects.filter(username__exact=username,password__exact=password)
            if user:
                #Step1:生成随机字符串(seesionID)
                #Step2：通过cookie发送给客户端
                #Step3：服务端保存 session
                print "seck"
                # print user.values()[0][username]
                request.session['username']=username
                print request.session
                # return render(request,'blog/index.html',{'userform':userform})
                return HttpResponseRedirect('/')
            else:
                return HttpResponse('用户名或者密码错误！')
    else:
        print "stsrat"
        userform=UserLoginForm()
    return render(request,'blog/login.html',{'userform':userform})
def sign_out(request):
    del request.session['username']
    return HttpResponseRedirect('/')

urls.py 的设置
blog/urls.py

#!/usr/bin/env python
#-*- coding:utf-8 _*-
"""
author:seck
time: 2018/01/28
"""
from django.conf.urls import include, url
from views import *
urlpatterns = [
    # Examples:
    # url(r'^$', 'blog_week_6.views.home', name='home'),
    url(r'^captcha/$',captcha),
    url(r'^login/$',login),
    url(r'^register/$',register),
    url(r'^sign_out/$',sign_out),
    url(r'', index,name='index'),
]

根目录下的urls.py

from django.conf.urls import include, url
from django.contrib import admin
urlpatterns = [
    # Examples:
    # url(r'^$', 'blog_week_8.views.home', name='home'),
    # url(r'^blog/', include('blog.urls')),
    url(r'',include('blog.urls')),
    url(r'^admin/', include(admin.site.urls)),
]

模板文件的代码
index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>{{title}}</title>
</head>
<body>
<h1>welcome {% if data %}{% for data in data%} {% if 'no' not in data %} {{data}} <a href="/sign_out/">退出</a> {% endif%} {% endfor %} {% endif %}</h1>
<a href="/login/">登录 </a>
<br>
<a href="/register/">注册 </a>
</body>
</html>

login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>登录页面</title>
</head>
<body>
<form method="post" enctype="multipart/form-data">
    {% csrf_token %}
    {{userform}}
    <input type="submit" name="sumit" value="login">
</form>
<a href="/">首页 </a>
<br>
<a href="/register/">注册 </a>
</body>
</html>

register.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>注册页面</title>
</head>
<body>
<form method="post" enctype="multipart/form-data">
    {% csrf_token %}
    {{userform}}
    验证码 <input type="text" name="cap"> <img src="{{'/captcha/'}}">
    <input type="submit" name="sumit" value="register">
</form>
<a href="/login/">登录 </a>
<br>
<a href="/">首页 </a>
</body>
</html>

项目代码https://github.com/Huseck/Django-study/tree/Django-study-4
本篇的运行结果图

例子四（2）

• 主要关注的几个逻辑问题
  • 怎么判断用户名是否重名
  • 继承自带的auth.user表是否能添加我们还需要的字段
  • 使用DjangoCaptcha判断机制是否符合要求
  • forms继承的关系和判断form表单数据
  • 准备
  • 这里我们使用自带的auth_user实现注册、登录验证。
  • 安装pip install django-simple-captcha==0.5.6
  • 配置 settings.py

INSTALLED_APPS = (
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'blog',
    'captcha',
)

根目录下的urls.py也要配置验证码的路由

urlpatterns = [
    url(r'', include('blog.urls')),
    url(r'^admin/', include(admin.site.urls)),
    url(r'^captcha/', include('captcha.urls')),
]

之后我们生成默认的数据库，成功之后会发现是有captcha_captchastore表的
然后开始编写我们的forms表单，blog目录下创建forms.py文件代码如下:

#!/usr/bin/env python
#-*- coding:utf-8 _*-
"""
author:seck
time: 2018/02/09
"""
from django import forms
from captcha.fields import CaptchaField
from django.contrib.auth.forms import UserCreationForm, AuthenticationForm
from .models import Users
class CreateUser(UserCreationForm):
    #UserCreationForm  里面自带的会验证重名
    username = forms.CharField(error_messages={'required':u"用户名不能为空"})
    password = forms.CharField(widget=forms.PasswordInput(),error_messages={'required':u"密码不能为空"})
    email = forms.CharField()
    captcha = CaptchaField()
class Auth(AuthenticationForm):
    username = forms.CharField(error_messages={'required': '用户名不能为空'})
    password = forms.CharField(widget=forms.PasswordInput(),error_messages={'required':u"密码不能为空"})
    captcha = CaptchaField()

我们编写一下视图函数

#coding:utf-8
from django.shortcuts import render,redirect
from django.http import HttpResponse
from django.contrib.auth import authenticate, login, logout
from django.contrib.auth import models
from django.contrib.auth.models import User
from .forms import CreateUser,Auth
def index(request):
    return render(request,'blog/index.html')
def register(request):
    createform = CreateUser(data=request.POST or None)
    if request.method == "POST":
        if createform.is_valid():
            username = createform.clean_username()
            password = createform.clean_password2()
            email = createform.clean()['email']
            #django 默认的user表创建用户使用create_user函数
            user = User.objects.create_user(username=username,password=password,email=email)
            user.save()
            return HttpResponse(u"注册成功")
        else:
            error_msg = createform.errors
            print error_msg
            return render(request,'blog/register.html',{"errors":error_msg})
    return render(request,'blog/register.html',{"createform":createform})
def auth(request):
    authform = Auth(data=request.POST or None)
    if request.method == "POST":
        #判断输入的数据是否符合规则
        if authform.is_valid():
            login(request,authform.get_user())
            return render(request,'blog/index.html',{})
        else:
            #如果数据不符合规则，就显示错误信息
            error_msg=authform.errors
            print authform.errors
            return render(request, 'blog/login.html', {"userform": authform, "errors": error_msg})
    return render(request,'blog/login.html',{"userform":authform})
def sign_out(request):
    logout(request)
    return redirect("/")

问题一验证重名
我们的CreateForm继承UserCreateForm 这个类继承User 这个又继承AbstractUser
然后找到关键位置

在文件site-packages\django\contrib\auth\models.py  394行左右找到
error_messages={
            'unique': _("A user with that username already exists."),
        })
    也就是is_valid  方法判断error是否有错误存在判断出重名  username 是unique=True 值唯一的定义

问题二验证码

当我们登录或者注册一个用户的时候，浏览器点击返回，在用此验证码注册其他的账号时，验证码应该是失效的，django-simple-captcha满足。
问题三form表单的继承
我们继承了UserCreationForm 和AuthenticationForm进行数据的验证，使用自带的验证方法实现用户的注册和登录。

结束语

当django自带的数据表和验证方法不满足需求时，需要自行扩展接口功能，实现应用。