Day24 中间件 自定义分页 ModelForm 序列化 缓存 信号

在views里边,怎么导入局部配置和全局配置

from s18day24  import  settings   
#这样导入的是仅仅用户自定义的配置

from django.conf   import  settings  
#这样导入的是全局的配置,包含用户自己定义的配置和内部自带的配置

装饰器怎么写:

装饰器有一个模板,

先定义一个函数,内层再定义一个函数,然后直接将函数名返回。

  函数里边写功能,最后return返回回去

模板:

def auth(func):
    def inner (request,*args,**kwargs):
        response = func (request,*args,**kwargs)
        return response 
    return inner



def auth(func):
    def inner(request,*args,**kwargs):
        # 在执行视图函数之前
        user_info = request.session.get(settings.USER_SESSION_KEY)
        if not user_info:
            return redirect('/login/')
        # 执行视图函数
        response = func(request,*args,**kwargs)
        return response
    return inner


 

中间件:

装饰器对于一个功能来说,能够做到很好的调节,但是对于某些功能来说,例如验证。

如果功能都需要用到它, 改动起来会比较麻烦。所以这时候我们可以利用中间件。

Django的请求周期:

请求过来路由系统,然后做url的匹配,当匹配成功了以后做路由分发执行视图函数,然后执行视图函数取数据等一系列操作,最后将网页字符串返回给用户。

中间件就是在路由系统前面加的一些规则(类)。

django中间件必须知道的图:

 1 process_request:
 2     #先正常执行request
 3 
 4 process_views:
 5     #先正常执行request,不执行后边的路由系统,然后先执行views,最后执行路由系统
 6 
 7 process_expection:
 8     #异常时执行
 9 
10 process_response:
11     #先正常执行request,然后先执行views,然后执行response,最后执行路由系统
12 
13 process_template_response:
14     #视图返回的对象中有render方法

网页有一个模板,写新网页的时候直接继承过来,改想改的内容就可以:

<html>
<head>
<title></title>
<style></style>
{% block css  %}{% endblock %}
</head>

<body>
{% block body  %}{% endblock %}
</body>

<script></script>
{% block body  %}{% endblock %}

</html>




#继承时写上继承哪个网页
{% extends "layout.html" %}
#然后后边修改某些模块就可以了

写一个分页的模块:

新建一个目录utils,然后在下面写一个pager.py文件:

"""
分页组件:
    使用方法:
        视图函数:
            from utils.pager import Pagination
            def host(request):
                all_count = models.Host.objects.all().count()
                # page_obj = Pagination(request.GET.get('page'),all_count,'/host/')
                page_obj = Pagination(request.GET.get('page'),all_count,request.path_info)
                host_list = models.Host.objects.all()[page_obj.start:page_obj.end]
                return render(request,'host.html',{'host_list':host_list,'page_html':  page_obj.page_html()})
        HTML:
            <style>
                .pager a{
                    display: inline-block;
                    padding: 3px 5px;
                    margin: 0 3px;
                    border: 1px solid #dddddd;
                }
                .pager a.active{
                    background-color: cadetblue;
                    color: white;
                }

            </style>

            <div class="pager">
                {{ page_html}}
            </div>




"""


from django.utils.safestring import mark_safe
class Pagination(object):
    def __init__(self,current_page,total_count,base_url, per_page_count=10,max_pager_num=11):
        """
        :param current_page: 用户请求的当前页
        :param per_page_count: 每页显示的数据条数
        :param total_count:  数据库中查询到的数据总条数
        :param max_pager_num: 页面上最多显示的页码
        """
        self.base_url = base_url
        total_page_count, div = divmod(total_count, per_page_count)
        if div:
            total_page_count += 1

        self.total_page_count = total_page_count
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1
        if current_page > total_page_count:
            current_page = total_page_count

        self.current_page = current_page
        self.per_page_count = per_page_count
        self.total_count = total_count
        self.max_pager_num = max_pager_num
        self.half_max_pager_num = int(max_pager_num/2)

    @property
    def start(self):
        return (self.current_page - 1) * self.per_page_count

    @property
    def end(self):
        return self.current_page * self.per_page_count

    def page_html(self):
        page_html_list = []

        if self.current_page <= 1:
            prev = "<a href='#'>上一页</a>"
        else:
            prev = "<a href='%s?page=%s'>上一页</a>" % (self.base_url,self.current_page - 1,)
        page_html_list.append(prev)

        max_pager_num = 11
        half_max_pager_num = int(max_pager_num / 2)

        # 数据总页数 < 页面上最大显示的页码个数
        if self.total_page_count <= max_pager_num:
            page_start = 1
            page_end = self.total_page_count
        else:
            # 数据比较多,已经超过11个页码
            # 如果当前页 <=5,显示 1-11
            if self.current_page <= half_max_pager_num:
                page_start = 1
                page_end = max_pager_num
            else:
                # 当前页 >=6
                if (self.current_page + 5) > self.total_page_count:
                    page_end = self.total_page_count
                    # page_start = current_page - 5
                    page_start = self.total_page_count - max_pager_num + 1
                else:
                    page_start = self.current_page - half_max_pager_num  # 当前页 - 5
                    page_end = self.current_page + half_max_pager_num  # 当前页 + 5

        for i in range(page_start, page_end + 1):
            if self.current_page == i:
                tag = "<a class='active' href='%s?page=%s'>%s</a>" % (self.base_url,i, i,)
            else:
                tag = "<a href='%s?page=%s'>%s</a>" % (self.base_url,i, i,)
            page_html_list.append(tag)

        # 下一页
        if self.current_page >= self.total_page_count:
            nex = "<a href='#'>下一页</a>"
        else:
            nex = "<a href='%s?page=%s'>下一页</a>" % (self.base_url,self.current_page + 1,)
        page_html_list.append(nex)

        return mark_safe("".join(page_html_list))


然后在views视图中写入函数:

def host(request):
    all_count = models.Host.objects.all().order_by('-id').count()
    # page_obj = Pagination(request.GET.get('page'),all_count,'/host/')
    page_obj = Pagination(request.GET.get('page'),all_count,request.path_info)
    host_list = models.Host.objects.all().order_by('-id')[page_obj.start:page_obj.end]
    return render(request,'host.html',{'host_list':host_list,'page_html':  page_obj.page_html()})


前面的models里是这样定义的:

class Host(models.Model):
    hostname = models.CharField(verbose_name='主机名',max_length=32)
    ip = models.CharField(max_length=32)# ip = models.GenericIPAddressField(protocol='both')
    port = models.IntegerField()
    user = models.ForeignKey(to='UserInfo',default=1)
    dp = models.ManyToManyField(to="Department")
原文地址:https://www.cnblogs.com/sexiaoshuai/p/8135957.html