Django補充 · 一個碼農的摸魚之路

## django頁面渲染具體流程　　在django的頁面渲染中，下面這段程序 ~~~ def test1(request): return render(request,'aa.html',{'data':'wusir'}) ~~~ 　　等同于 ~~~ from django.template import loader def test1(request): html = loader.get_template('aa.html') html_str = html.render({'data':'wusir'}) return HttpResponse(html_str) ~~~ ## django中自定義simple\_tag 　　1、在app目錄下創建一個文件夾名字叫templatetags，名字不能改，在該文件夾下隨便建一個xxx.py文件，寫入以下代碼 ~~~ from django import template register = template.Library() @register.simple_tag def func(a1,a2): #(參數任意多) ....... ~~~ 　　2、在前端頁面的頂部寫上{% load xxx %}，然后就可以使用后端所定義的函數{% func 1 2 %} PS：simple\_tag不能作為if后面的判斷條件，但是參數任意多 ## django中自定義filter 　　1、在app目錄下創建一個文件夾名字叫templatetags，名字不能改，在該文件夾下隨便建一個xxx.py文件，寫入以下代碼 ~~~ from django import template register = template.Library() @register.filter def func(a1,a2): #(參數最多兩個) ....... ~~~ 　　2、在前端頁面的頂部寫上{% load xxx %}，然后就可以使用{ { xxx|func:yyy } } ,xxx,yyy對應兩個參數，如果函數只有一個參數，func后面的冒號和后面的參數就不用寫了。 PS：能作為if后面的判斷條件，但是參數最多兩個，并且冒號后面不能加空格 ## 基于FBV、CBV的用戶認證裝飾器　　FBV ``` def login(request): if request.method == 'GET': return render(request,'login.html') if request.method == 'POST': username = request.POST.get('username') password = request.POST.get('password') obj = User.objects.filter(username=username).first() if not obj: return redirect('/app/login/') if password == obj.pwd: res = redirect('/app/index/') res.set_cookie('username',username) return res else: return redirect('/app/login/') def auth(func): def inner(request,*args,**kwargs): res = request.COOKIES.get('username') if not res: return redirect('/app/login/') return func(request,*args,**kwargs) return inner @auth def index(request): res = request.COOKIES.get('username') return render(request,'index.html',{'data':res}) views.py ``` 　　CBV ``` def login(request): if request.method == 'GET': return render(request,'login.html') if request.method == 'POST': username = request.POST.get('username') password = request.POST.get('password') obj = User.objects.filter(username=username).first() if not obj: return redirect('/app/login/') if password == obj.pwd: res = redirect('/app/index/') res.set_cookie('username',username) return res else: return redirect('/app/login/') def auth(func): def inner(request,*args,**kwargs): res = request.COOKIES.get('username') if not res: return redirect('/app/login/') return func(request,*args,**kwargs) return inner from django import views from django.utils.decorators import method_decorator #三種方式：在每個函數上加，在dispatch上加，在類上加裝飾器 method_decorator(auth,name='dispatch') class Order(views.View): # @method_decorator(auth) # def dispatch(self, request, *args, **kwargs): # return super(Order, self).dispatch(request, *args, **kwargs) # @method_decorator(auth) def get(self,request): res = request.COOKIES.get('username') # if not res: # return redirect('/app/login/') return render(request,'index.html',{'data':res}) views.py ``` ## django之Form組件 django中的Form一般有兩種功能： * 輸入html * 驗證用戶輸入 ``` from django import forms class FM(forms.Form): user = forms.CharField(error_messages={'required':'用戶名不能為空'}) email = forms.CharField(error_messages={'required':'郵箱不能為空','invalid':'郵箱格式錯誤'}) pwd = forms.CharField(max_length=12,min_length=6,error_messages={'required':'密碼不能為空','max_length': '最大長度不能超過12','min_length': '最小長度不能低于6'}) def test_form(request): if request.method == 'GET': obj = FM() return render(request,'test_form.html',{'obj':obj}) elif request.method == 'POST': obj = FM(request.POST) r1 = obj.is_valid() if r1: print(obj.cleaned_data) Person.objects.create(**obj.cleaned_data) else: print(obj.errors) # print(obj.errors.as_json()) # print(obj.errors['user'][0]) return render(request,'test_form.html',{'obj':obj}) return render(request,'test_form.html') views.py ``` ``` <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> {#<form action="/app/test_form/" method="post">#} {# {% csrf_token %}#} {# <p><input type="text" name="user">{{ obj.errors.user.0 }}</p>#} {# <p><input type="email" name="email">{{ obj.errors.email.0 }}</p>#} {# <p><input type="password" name="pwd">{{ obj.errors.pwd.0 }}</p>#} {# <input type="submit" value="提交">#} {#</form>#} {#<form action="/app/test_form/" method="post">#} {# {% csrf_token %}#} {# <p>{{ obj.user }}{{ obj.errors.user.0 }}</p>#} {# <p>{{ obj.email }}{{ obj.errors.email.0 }}</p>#} {# <p>{{ obj.pwd }}{{ obj.errors.pwd.0 }}</p>#} {# <input type="submit" value="提交">#} {#</form>#} <form action="/app/test_form/" method="post"> {% csrf_token %} {# 方式一#} {# {{ obj.as_p }}#} {# 方式二#} {# {{ obj.as_ul }}#} {# 方式三#} <table> {{ obj.as_table }} </table> <input type="submit" value="提交"> </form> </body> </html> 前端頁面 ``` ?PS:以后使用的時候將forms改成fields，fields里面有一個插件widget，可以定制樣式 ``` from django import forms from django.forms import fields from django.forms import widgets class FM(forms.Form): user = fields.CharField(error_messages={'required':'用戶名不能為空'},widget=widgets.Textarea(attrs={ 'class':'c1' })) email = fields.CharField(error_messages={'required':'郵箱不能為空','invalid':'郵箱格式錯誤'},widget=widgets.PasswordInput) pwd = fields.CharField(max_length=12,min_length=6,error_messages={'required':'密碼不能為空','max_length': '最大長度不能超過12','min_length': '最小長度不能低于6'}) def test_form(request): if request.method == 'GET': obj = FM() return render(request,'test_form.html',{'obj':obj}) elif request.method == 'POST': obj = FM(request.POST) r1 = obj.is_valid() if r1: print(obj.cleaned_data) Person.objects.create(**obj.cleaned_data) else: print(obj.errors) # print(obj.errors.as_json()) # print(obj.errors['user'][0]) return render(request,'test_form.html',{'obj':obj}) return render(request,'test_form.html') views.py ``` ?詳細內容參考：[https://www.cnblogs.com/wupeiqi/articles/6144178.html](https://www.cnblogs.com/wupeiqi/articles/6144178.html) ## 跨站請求偽造一、簡介　　django為用戶實現防止跨站請求偽造的功能，通過中間件?django.middleware.csrf.CsrfViewMiddleware 來完成。而對于django中設置防跨站請求偽造功能有分為全局和局部。全局：　　中間件?django.middleware.csrf.CsrfViewMiddleware 局部： * @csrf\_protect，為當前函數強制設置防跨站請求偽造功能，即便settings中沒有設置全局中間件。 * @csrf\_exempt，取消當前函數防跨站請求偽造功能，即便settings中設置了全局中間件。注：from django.views.decorators.csrf import csrf\_exempt,csrf\_protect 二、應用 1、普通表單 ~~~ html中設置Token: {% csrf_token %} ~~~ 2、Ajax請求 ``` <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <form action="/app/test1/" method="post"> {% csrf_token %} <input type="text" placeholder="用戶名" name="user"> <input type="password" placeholder="密碼" name="pwd"> <input type="submit" value="提交"> <input id="btn" type="button" value="按鈕"> </form> <script src="/static/jquery-1.12.4.js"></script> <script src="/static/jquery.cookie.js"></script> <script> $('#btn').click(function () { {# 給除GET|HEAD|OPTIONS|TRACE幾個方法以外的方法全部設置csrftoken#} {# 過濾方法#} var csrftoken = $.cookie('csrftoken'); function csrfSafeMethod(method) { return (/^(GET|HEAD|OPTIONS|TRACE)$/.test(method)); } {# 設置csrftoken#} $.ajaxSetup({ beforeSend: function(xhr, settings) { if (!csrfSafeMethod(settings.type) && !this.crossDomain) { xhr.setRequestHeader("X-CSRFToken", csrftoken); } } }); $.ajax({ url:'/app/test1/', type:'GET', data:{'user':'alex'}, {# headers: {'X-CSRFtoken': $.cookie('csrftoken')}, 單個ajax請求設置csrftoken#} success:function (res) { } }) }) </script> </body> </html> ```