django 自定义分页组件

"""
分页组件应用：

1. 在视图函数中
   queryset = models.Issues.objects.filter(project_id=project_id)
   page_object = Pagination(
   current_page=request.GET.get('page'),
   all_count=queryset.count(),
   base_url=request.path_info,
   query_params=request.GET
   )
   issues_object_list = queryset[page_object.start:page_object.end]

   context = {
   'issues_object_list': issues_object_list,
   'page_html': page_object.page_html()
   }
   return render(request, 'issues.html', context)

2. 前端
   {% for item in issues_object_list %}

   {{ page_html|safe }}

"""

class Pagination(object):
def init(self, current_page, all_count, base_url, query_params, per_page=30, pager_page_count=11):
"""
分页初始化
:param current_page: 当前页码
:param per_page: 每页显示数据条数
:param all_count: 数据库中总条数
:param base_url: 基础URL
:param query_params: QueryDict对象，内部含所有当前URL的原条件
:param pager_page_count: 页面上最多显示的页码数量
"""
self.base_url = base_url
try:
self.current_page = int(current_page)
if self.current_page <= 0:
self.current_page = 1
except Exception as e:
self.current_page = 1
query_params = query_params.copy()
query_params._mutable = True
self.query_params = query_params
self.per_page = per_page
self.all_count = all_count
self.pager_page_count = pager_page_count
pager_count, b = divmod(all_count, per_page)
if b != 0:
pager_count += 1
self.pager_count = pager_count

    half_pager_page_count = int(pager_page_count / 2)
    self.half_pager_page_count = half_pager_page_count

@property
def start(self):
    """
    数据获取值起始索引
    :return:
    """
    return (self.current_page - 1) * self.per_page

@property
def end(self):
    """
    数据获取值结束索引
    :return:
    """
    return self.current_page * self.per_page

def page_html(self):
    """
    生成HTML页码
    :return:
    """
    if self.all_count == 0:
        return ""

    # 如果数据总页码pager_count<11 pager_page_count
    if self.pager_count < self.pager_page_count:
        pager_start = 1
        pager_end = self.pager_count
    else:
        # 数据页码已经超过11
        # 判断： 如果当前页 <= 5 half_pager_page_count
        if self.current_page <= self.half_pager_page_count:
            pager_start = 1
            pager_end = self.pager_page_count
        else:
            # 如果： 当前页+5 > 总页码
            if (self.current_page + self.half_pager_page_count) > self.pager_count:
                pager_end = self.pager_count
                pager_start = self.pager_count - self.pager_page_count + 1
            else:
                pager_start = self.current_page - self.half_pager_page_count
                pager_end = self.current_page + self.half_pager_page_count

    page_list = []

    if self.current_page <= 1:
        prev = '<li><a href="#">上一页</a></li>'
    else:
        self.query_params['page'] = self.current_page - 1
        prev = '<li><a href="%s?%s">上一页</a></li>' % (self.base_url, self.query_params.urlencode())
    page_list.append(prev)
    for i in range(pager_start, pager_end + 1):
        self.query_params['page'] = i
        if self.current_page == i:
            tpl = '<li class="active"><a href="%s?%s">%s</a></li>' % (
                self.base_url, self.query_params.urlencode(), i,)
        else:
            tpl = '<li><a href="%s?%s">%s</a></li>' % (self.base_url, self.query_params.urlencode(), i,)
        page_list.append(tpl)

    if self.current_page >= self.pager_count:
        nex = '<li><a href="#">下一页</a></li>'
    else:
        self.query_params['page'] = self.current_page + 1
        nex = '<li><a href="%s?%s">下一页</a></li>' % (self.base_url, self.query_params.urlencode(),)
    page_list.append(nex)

    if self.all_count:
        tpl = "<li class='disabled'><a>共%s条数据，页码%s/%s页</a></li>" % (
        self.all_count, self.current_page, self.pager_count,)
        page_list.append(tpl)
    page_str = "".join(page_list)
    return page_str