Django 自定义分页组件

Posted 2020-11-30 zc3614

 

自定义分页组件类

"""
自定义分页组件
"""
page.py

class Pagination(object):
    def __init__(self, current_page, all_count,params, base_url,  per_page_num=8, pager_count=11, ):
        """
        封装分页相关数据
        :param current_page: 当前页
        :param all_count:    数据库中的数据总条数
        :param base_url: 分页中显示的URL前缀
        :param params:  request.GET 对象
        :param per_page_num: 每页显示的数据条数
        :param pager_count:  最多显示的页码个数
        """
        try:
            current_page = int(current_page)　　#尝试转换成int类型
        except Exception as e:
            current_page = 1　　#失败设置默认为第一页
        if current_page < 1:
            current_page = 1　　#当前页小于1时，设为1
        self.current_page = current_page
        self.all_count = all_count
        self.per_page_num = per_page_num
        self.base_url = base_url
        all_pager, tmp = divmod(all_count, per_page_num) 　　#函数把除数和余数运算结果结合起来，返回一个包含商和余数的元组(a // b, a % b)
        if tmp:　　#有余数，说明还需要加一页
            all_pager += 1
        self.all_pager = all_pager
        self.pager_count = pager_count
        self.pager_count_half = int((pager_count - 1) / 2)

        import copy
        params = copy.deepcopy(params)
        params._mutable = True
        self.params = params  # self.params : {"page":77,"title":"python","nid":1}

    @property
    def start(self):　　#当前页的第一个元素的索引
        return (self.current_page - 1) * self.per_page_num

    @property
    def end(self):　　#当前页的最后一个索引
        return self.current_page * self.per_page_num

    def page_html(self):
        # 如果总页码 < 最多显示的页面个数 11：
        if self.all_pager <= self.pager_count:
            pager_start = 1
            pager_end = self.all_pager + 1
        # 页码结束 = 最多显示的页码个数+1
        else:
            # 当前页如果<=页面上最多显示(11-1)/2个页码
            if self.current_page <= self.pager_count_half:
                pager_start = 1
                pager_end = self.pager_count + 1
            # 当前页大于5
            else:
                # 页码翻到最后
                if (self.current_page + self.pager_count_half) > self.all_pager:
                    pager_start = self.all_pager - self.pager_count + 1
                    pager_end = self.all_pager + 1
                else:
                    pager_start = self.current_page - self.pager_count_half
                    pager_end = self.current_page + self.pager_count_half + 1
        page_html_list = []
        self.params["page"] = 1
        first_page = ‘<li><a href="%s?%s">首页</a></li>‘ % (self.base_url, self.params.urlencode(),)
        page_html_list.append(first_page)
        if self.current_page <= 1:
            prev_page = ‘<li class="disabled"><a href="#">上一页</a></li>‘
        else:
            self.params["page"] = self.current_page - 1
            prev_page = ‘<li><a href="%s?%s">上一页</a></li>‘ % (self.base_url, self.params.urlencode(),)
        page_html_list.append(prev_page)
        for i in range(pager_start, pager_end):
            self.params["page"] = i
            if i == self.current_page:
                temp = ‘<li class="active"><a href="%s?%s">%s</a></li>‘ % (self.base_url, self.params.urlencode(), i,)
            else:
                temp = ‘<li><a href="%s?%s">%s</a></li>‘ % (self.base_url, self.params.urlencode(), i,)
            page_html_list.append(temp)
        if self.current_page >= self.all_pager:
            next_page = ‘<li class="disabled"><a href="#">下一页</a></li>‘
        else:
            self.params["page"] = self.current_page + 1
            next_page = ‘<li><a href="%s?%s">下一页</a></li>‘ % (self.base_url, self.params.urlencode(),)
        page_html_list.append(next_page)
        self.params["page"] = self.all_pager
        last_page = ‘<li><a href="%s?%s">尾页</a></li>‘ % (self.base_url, self.params.urlencode(),)
        page_html_list.append(last_page)
        return ‘‘.join(page_html_list)

在视图函数内调用

views.py


from django.shortcuts import render,HttpResponse

from .models import *

def index(request):
    current_page = request.GET.get("page", 1)
    all_count = Book.objects.all().count()
　　 base_url = request.path  
    from app01.utils.page import Pagination
    pagination = Pagination(int(current_page),all_count,base_url,request.GET, per_page_num=8, pager_count=11,)

    # def __init__(self, current_page, all_count, base_url, params, per_page_num=8, pager_count=11, ):
    book_list = Book.objects.all()[pagination.start:pagination.end] #查询集切片，得到当前页的查询集，交给html遍历

    from django.http.request import QueryDict
    # dic = QueryDict(mutable=True)
    # dic["info"] = 123
    # print(type(request.GET))
    # request.GET["info"]=123
    import copy
    params = copy.deepcopy(request.GET)
    params["xxx"] = 123
    return render(request, "index.html", locals())

templates模版内

index.html

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 引入的 Bootstrap 核心 CSS 文件 -->
    <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>


<ul>
    {% for item in book_list %} #遍历查询集对象
        <li>{{ item }}</li> 　　#根据需要可以取对象的属性
    {% endfor %}

</ul>
<nav>
    <ul class="pagination">
        {{ pagination.page_html|safe }}
    </ul>
</nav>


</body>
</html>