django-自定义分页

自定义分页:

功能：

1. 首尾页跳转
2. 保存搜索条件

#自定义分页
#官方推荐,页码数为奇数
class PageNation:
    def __init__(self,base_url,current_page_num,total_counts,request,per_page_counts=10,page_number=5,):
        '''
        :param base_url:   分页展示信息的基础路径
        :param current_page_num:  当前页页码
        :param total_counts:  总的数据量
        :param per_page_counts:  每页展示的数据量
        :param page_number:  显示页码数
        '''

        self.base_url = base_url
        self.current_page_num = current_page_num
        self.total_counts = total_counts
        self.per_page_counts = per_page_counts
        self.page_number = page_number
        self.request = request
        try:
            self.current_page_num = int(self.current_page_num)

        except Exception:
            self.current_page_num = 1
        if self.current_page_num < 1:
            self.current_page_num = 1

        half_page_range = self.page_number // 2
        # 计算总页数
        self.page_number_count, a = divmod(self.total_counts, self.per_page_counts)


        if a:
            self.page_number_count += 1


        if self.current_page_num > self.page_number_count:
            self.current_page_num = self.page_number_count

        if self.page_number_count <= self.page_number:
            self.page_start = 1
            self.page_end = self.page_number_count
        else:
            if self.current_page_num <= half_page_range:  #2
                self.page_start = 1
                self.page_end = page_number  #5
            elif self.current_page_num + half_page_range >= self.page_number_count:
                self.page_start = self.page_number_count - self.page_number + 1
                self.page_end = self.page_number_count
            else:
                self.page_start = self.current_page_num - half_page_range
                self.page_end = self.current_page_num + half_page_range


        import copy
        from django.http.request import QueryDict

        self.params = copy.deepcopy(request.GET)

        # ?condition = qq & wd = 1 & page = 3
        # params['page'] = current_page_num
        # query_str = params.urlencode()
    #数据切片依据,起始位置
    @property
    def start_num(self):
        start_num = (self.current_page_num - 1) * self.per_page_counts
        return start_num

    #数据切片依据,终止位置
    @property
    def end_num(self):
        end_num = self.current_page_num * self.per_page_counts
        return end_num

    # 拼接HTMl标签
    def page_html(self):
        tab_html = ''
        tab_html += '<nav aria-label="Page navigation" class="pull-right"><ul class="pagination">'
        #首页
        self.params['page'] = 1
        showye = '<li><a href="{0}?{1}" aria-label="Previous" ><span aria-hidden="true">首页</span></a></li>'.format(self.base_url,self.params.urlencode())
        tab_html += showye
        # 上一页
        if self.current_page_num == 1:
            previous_page = '<li disabled><a href="#" aria-label="Previous" ><span aria-hidden="true">&laquo;</span></a></li>'
        else:
            self.params['page'] = self.current_page_num - 1
            previous_page = '<li><a href="{0}?{1}" aria-label="Previous" ><span aria-hidden="true">&laquo;</span></a></li>'.format(
                self.base_url,self.params.urlencode())
        tab_html += previous_page

        #循环生成页码标签
        for i in range(self.page_start, self.page_end + 1):
            # request.GET  {condition: qq, wd: 1,'page':1} request.GET.urlencode() condition=qq&wd=1&page=4

            self.params['page'] = i # {condition: qq, wd: 1,'page':1} urlencode() -- condition=qq&wd=1&page=4

            if self.current_page_num == i:

                one_tag = '<li class="active"><a href="{0}?{2}">{1}</a></li>'.format(self.base_url, i,self.params.urlencode()) #?condition=qq&wd=1&page=3
            else:
                one_tag = '<li><a href="{0}?{2}">{1}</a></li>'.format(self.base_url, i,self.params.urlencode())
            tab_html += one_tag

        # 下一页
        if self.current_page_num == self.page_number_count:
            next_page = '<li disabled><a href="#" aria-label="Next"><span aria-hidden="true">&raquo;</span></a></li>'
        else:
            self.params['page'] = self.current_page_num + 1
            next_page = '<li><a href="{0}?{1}" aria-label="Next"><span aria-hidden="true">&raquo;</span></a></li>'.format(self.base_url, self.params.urlencode())
        tab_html += next_page

        # 尾页
        self.params['page'] = self.page_number_count
        weiye = '<li><a href="{0}?{1}" aria-label="Previous" ><span aria-hidden="true">尾页</span></a></li>'.format(
            self.base_url, self.params.urlencode())

        tab_html += weiye
        tab_html += '</ul></nav>'

        return tab_html

# 公共客户信息展示
@login_required
def customers(request):
    # 获取用户选择的和用户输入的搜索内容,默认为空,不选择和不输入get的返回结果为None
    choice = request.GET.get("choice",'')
    wd = request.GET.get("wd",'')
    # 在查询时设置成包含的情况contains--->关键字
    choice = choice + '__contains'
    # 默认get第一次请求第一页
    current_page_num = request.GET.get('page', 1)

    if wd:
        # 实例化一个Q对象
        q = Q()
        # 指定连接条件,默认是and
        # q.connector = "or"
        # 必须是元组,因为只接收一个参数
        q.children.append((choice,wd))
        # q.children.append(('name__contains', '小'))
        # 名字中包含wd字段的所有信息  qq__contains 66   name__contains 小
        # models.Customer.objects.filter(name__contains=wd)
        customers_obj = models.Customer.objects.filter(q)
    else:
        # 所有销售为空的，就是公共客户
        customers_obj = models.Customer.objects.filter(consultant__isnull=True)
    # 每页展示的数据量
    page_counts = 5
    # 页码数
    page_number = 7
    # 总数据
    total_count = customers_obj.count()
    if total_count:
        # 实列化分页的类
        page_obj = page.PageNation(request.path, current_page_num, total_count, request,page_counts, page_number)
        # 切片:从总数居中每次切出多少条数据展示在页面上
        customers_obj = customers_obj.order_by('-pk')[page_obj.start_num:page_obj.end_num]
        ret_html = page_obj.page_html()

        return render(request,"customers.html",{"customers_obj":customers_obj,"ret_html":ret_html})
    else:
        return render(request,"404.html")