Flask系列(五)Flask实现分页

一、flask分页组件

from urllib.parse import urlencode,quote,unquote
class Pagination(object):
    """
    自定义分页
    """
    def __init__(self,current_page,total_count,base_url,params,per_page_count=10,max_pager_count=11):
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1
        if current_page <=0:
            current_page = 1
        self.current_page = current_page
        # 数据总条数
        self.total_count = total_count

        # 每页显示10条数据
        self.per_page_count = per_page_count

        # 页面上应该显示的最大页码
        max_page_num, div = divmod(total_count, per_page_count)
        if div:
            max_page_num += 1
        self.max_page_num = max_page_num

        # 页面上默认显示11个页码（当前页在中间）
        self.max_pager_count = max_pager_count
        self.half_max_pager_count = int((max_pager_count - 1) / 2)

        # URL前缀
        self.base_url = base_url

        # request.GET
        import copy
        params = copy.deepcopy(params)
        # params._mutable = True
        get_dict = params.to_dict()
        # 包含当前列表页面所有的搜/索条件
        # {source:[2,], status:[2], gender:[2],consultant:[1],page:[1]}
        # self.params[page] = 8
        # self.params.urlencode()
        # source=2&status=2&gender=2&consultant=1&page=8
        # href="/hosts/?source=2&status=2&gender=2&consultant=1&page=8"
        # href="%s?%s" %(self.base_url,self.params.urlencode())
        self.params = get_dict

    @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):
        # 如果总页数 <= 11
        if self.max_page_num <= self.max_pager_count:
            pager_start = 1
            pager_end = self.max_page_num
        # 如果总页数 > 11
        else:
            # 如果当前页 <= 5
            if self.current_page <= self.half_max_pager_count:
                pager_start = 1
                pager_end = self.max_pager_count
            else:
                # 当前页 + 5 > 总页码
                if (self.current_page + self.half_max_pager_count) > self.max_page_num:
                    pager_end = self.max_page_num
                    pager_start = self.max_page_num - self.max_pager_count + 1   #倒这数11个
                else:
                    pager_start = self.current_page - self.half_max_pager_count
                    pager_end = self.current_page + self.half_max_pager_count

        page_html_list = []
        # {source:[2,], status:[2], gender:[2],consultant:[1],page:[1]}
        # 首页
        self.params['page'] = 1
        first_page = '<li><a href="%s?%s">首页</a></li>' % (self.base_url,urlencode(self.params),)
        page_html_list.append(first_page)
        # 上一页
        self.params["page"] = self.current_page - 1
        if self.params["page"] < 1:
            pervious_page = '<li class="disabled"><a href="%s?%s" aria-label="Previous">上一页</span></a></li>' % (self.base_url, urlencode(self.params))
        else:
            pervious_page = '<li><a href = "%s?%s" aria-label = "Previous" >上一页</span></a></li>' % ( self.base_url, urlencode(self.params))
        page_html_list.append(pervious_page)
        # 中间页码
        for i in range(pager_start, pager_end + 1):
            self.params['page'] = i
            if i == self.current_page:
                temp = '<li class="active"><a href="%s?%s">%s</a></li>' % (self.base_url,urlencode(self.params), i,)
            else:
                temp = '<li><a href="%s?%s">%s</a></li>' % (self.base_url,urlencode(self.params), i,)
            page_html_list.append(temp)

        # 下一页
        self.params["page"] = self.current_page + 1
        if self.params["page"] > self.max_page_num:
            self.params["page"] = self.current_page
            next_page = '<li class="disabled"><a href = "%s?%s" aria-label = "Next">下一页</span></a></li >' % (self.base_url, urlencode(self.params))
        else:
            next_page = '<li><a href = "%s?%s" aria-label = "Next">下一页</span></a></li>' % (self.base_url, urlencode(self.params))
        page_html_list.append(next_page)

        # 尾页
        self.params['page'] = self.max_page_num
        last_page = '<li><a href="%s?%s">尾页</a></li>' % (self.base_url, urlencode(self.params),)
        page_html_list.append(last_page)

        return ''.join(page_html_list)

二、使用组件

#!usr/bin/env python
# -*- coding:utf-8 -*-
from flask import Flask,render_template,request,redirect
from pager import Pagination
from urllib.parse import urlencode
app = Flask(__name__)

=========================django的用法=======================================
# pager_obj = Pagination(request.GET.get('page', 1), len(HOST_LIST), request.path_info, request.GET)
# host_list = HOST_LIST[pager_obj.start:pager_obj.end]
# html = pager_obj.page_html()
# return render(request, 'hosts.html', {'host_list': host_list, "page_html": html})

@app.route('/pager')
def pager():
    li = []
    for i in range(1,100):
        li.append(i)
    # print(li)
　　
　　===================================flask的用法===============================
    pager_obj = Pagination(request.args.get("page",1),len(li),request.path,request.args,per_page_count=10)
    # print(request.args)
    index_list = li[pager_obj.start:pager_obj.end]
    html = pager_obj.page_html()
   return render_template("pager.html",index_list=index_list, html = html,condition=path)

if __name__ == '__main__':
    app.run(debug=True)

pager.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width">
    <title>Title</title>
    <link rel="stylesheet" href="/static/bootstrap-3.3.7-dist/css/bootstrap.min.css">
    <style>
        .container{
            margin-top: 20px;
        }
    </style>
</head>
<body>
<div class="container">
    <a href="/add?{{ condition }}"><button class="btn btn-primary">添加</button></a>
    <div class="row " style="margin-top: 10px">
            <ul>
                {% for foo in index_list %}
                    <li>{{ foo }}</li>
                {% endfor %}
            </ul>
            <nav aria-label="Page navigation" class="pull-right">
                <ul class="pagination">
                    {{ html|safe }}
                </ul>
            </nav>
    </div>
</div>
</body>
</html>