手写Django分页组件

一次编写,多次使用

"""
    @Author: xiaozhi
    @Email: [email protected]
    @FileName: pagination.py
    @DateTime: 2022/5/27
    @SoftWare: PyCharm
"""

"""
	自定义分页组件
	如想再次使用,需做如下几件事:
	在视图函数中:
			from xxx import 脚本文件    # 导入
	    def pretty_list(request):
	        # 1. 根据自己的情况去筛选自己的数据
	        queryset = models.PrettyNum.objects.all()
	
	        # 2. 实例化分页对象
	        page_object = Pagination(request, queryset)
	
	        page_queryset = page_object.page_queryset  # 分完页的数据
	
	        page_string = page_object.html()  # 页码
	
	        context = {
	            "search_data": search_data,
	
	            "queryset": page_queryset,  # 分完页的数据
	            "page_string": page_string,  # 页码
	        }
	
	        return render(request, "pretty_list.html", context)
	
	在HTML页面中:
	    {% for obj in queryset %}
	        {
    
    { obj.xx }}
	    {% endfor %}
	
	    <ul class="pagination">
	        {
    
    { page_string }}
	    </ul>
"""

"""
    分页时,保留原来的搜索条件
"""

from django.utils.safestring import mark_safe
import copy


class Pagination(object):

    def __init__(self, request, queryset, page_size=10, page_param="page", plus=5):
        """
        :param request: 请求的对象
        :param queryset: 符合条件的数据(根据这个数据给他进行分页处理)
        :param page_size: 每页显示多少条数据
        :param page_param: 在URL中传递的获取分页的参数,例如:/pretty/list/?page=1
        :param plus: 显示当前页的前或后几页(根据页码得来)
        """

        # 搜索之后分页,条件
        query_dict = copy.deepcopy(request.GET)
        # request.GET可以获取URL中所有的参数,request.GET.urlencode()可以将参数拼接为URL,如:q=123&xx=111&bb=222
        # request.GET._mutable=True, 修改为True,可以拼接参数,可以在from django.http.request import QueryDict中查看源码
        query_dict._mutable = True
        self.query_dict = query_dict
        self.page_param = page_param

        page = request.GET.get(page_param, "1")

        if page.isdecimal():
            page = int(page)
        else:
            page = 1
        self.page = page
        self.page_size = page_size

        self.start = (page - 1) * page_size
        self.end = page * page_size
        self.page_queryset = queryset[self.start:self.end]

        total_count = queryset.count()  # 数据总条数
        total_page_count, div = divmod(total_count, page_size)
        if div:
            total_page_count += 1
        self.total_page_count = total_page_count
        self.plus = plus

    def html(self):
        # 计算出,显示当前也的前5页和后5页

        # 数据库中的数据比较少,没有达到11页
        if self.total_page_count <= 2 * self.plus + 1:
            start_page = 1
            end_page = self.total_page_count
        # 数据库中的数据比较多,大于11页
        else:
            # 当前页<5时(小极值)
            if self.page <= self.plus:
                start_page = 1
                end_page = 2 * self.plus
            # 当前页>5时(大极值)
            else:
                # 当前页 + 5 > 总页码
                if (self.page + self.plus) > self.total_page_count:
                    start_page = self.total_page_count - 2 * self.plus
                    end_page = self.total_page_count
                else:
                    start_page = self.page - self.plus
                    end_page = self.page + self.plus

        # 页码
        page_str_list = []

        self.query_dict.setlist(self.page_param, [1])

        # 首页
        page_str_list.append('<li><a href="?{}">首页</a></li>'.format(self.query_dict.urlencode()))

        # 上一页
        if self.page > 1:
            self.query_dict.setlist(self.page_param, [self.page - 1])
            prev = '<li><a href="?{}">上一页</a></li>'.format(self.query_dict.urlencode())
        else:
            self.query_dict.setlist(self.page_param, [1])
            prev = '<li><a href="?{}">上一页</a></li>'.format(self.query_dict.urlencode())

        page_str_list.append(prev)

        # 页面
        for i in range(start_page, end_page + 1):
            self.query_dict.setlist(self.page_param, [i])
            if i == self.page:
                ele = '<li class="active"><a href="?{}">{}</a></li>'.format(self.query_dict.urlencode(), i)
            else:
                ele = '<li><a href="?{}">{}</a></li>'.format(self.query_dict.urlencode(), i)
            page_str_list.append(ele)
        # page_string = "".join(page_str_list)  # page_string是字符串,需要使用mark_safe()转换一下,如下

        # 下一页
        if self.page < self.total_page_count:
            self.query_dict.setlist(self.page_param, [self.page + 1])
            prev = '<li><a href="?{}">下一页</a></li>'.format(self.query_dict.urlencode())
        else:
            self.query_dict.setlist(self.page_param, [self.total_page_count])
            prev = '<li><a href="?{}">下一页</a></li>'.format(self.query_dict.urlencode())

        page_str_list.append(prev)

        # 尾页
        self.query_dict.setlist(self.page_param, [self.total_page_count])
        page_str_list.append('<li><a href="?{}">尾页</a></li>'.format(self.query_dict.urlencode()))

        search_string = """
                            <li>
                                <form style="float: left;margin-left: -1px" method="get">
                                    <input name="page"
                                           style="position: relative;float:left;display: inline-block;width: 80px;border-radius: 0;"
                                           type="text" class="form-control" placeholder="页码">
                                    <button style="border-radius: 0" class="btn btn-default" type="submit">跳转</button>
                                </form>
                            </li>
                            """
        page_str_list.append(search_string)
        page_string = mark_safe("".join(page_str_list))
        return page_string

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转载自blog.csdn.net/zZZxiaozhi/article/details/125002494