Django之分页器组件与自定义

Django之分页器组件一

class Pagination(object):
def init(self,current_page,all_count,per_page_num=2,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 per_page_num: 每页显示的数据条数
:param pager_count: 最多显示的页码个数

用法:
queryset = model.objects.all()
page_obj = Pagination(current_page,all_count)
page_data = queryset[page_obj.start:page_obj.end]
获取数据用page_data而不再使用原始的queryset
获取前端分页样式用page_obj.page_html
"""
try:
current_page = int(current_page)
except Exception as e:
current_page = 1

if current_page <1:
current_page = 1

self.current_page = current_page

self.all_count = all_count
self.per_page_num = per_page_num

总页码

all_pager, tmp = divmod(all_count, per_page_num)
if tmp:
all_pager += 1
self.all_pager = all_pager

self.pager_count = pager_count
self.pager_count_half = int((pager_count - 1) / 2)

@property
def start(self):
return (self.current_page - 1) * self.per_page_num

@property
def end(self):
return self.current_page * self.per_page_num

def page_html(self):
# 如果总页码 < 11个：
if self.all_pager <= self.pager_count:
pager_start = 1
pager_end = self.all_pager + 1
# 总页码 > 11
else:
# 当前页如果<=页面上最多显示11/2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_end = self.all_pager + 1
pager_start = self.all_pager - self.pager_count + 1
else:
pager_start = self.current_page - self.pager_count_half
pager_end = self.current_page + self.pager_count_half + 1

page_html_list = []
# 添加前面的nav和ul标签
page_html_list.append('''
<nav aria-label='Page navigation>'


    ''')
    first_page = '
  • 首页
    • ' % (1)
    page_html_list.append(first_page)

    if self.current_page <= 1:
    prev_page = '

  • 上一页
    • '
    else:
    prev_page = '
  • 上一页
    • ' % (self.current_page - 1,)

    page_html_list.append(prev_page)

    for i in range(pager_start, pager_end):
    if i == self.current_page:
    temp = '

  • %s
    • ' % (i, i,)
    else:
    temp = '
  • %s
    • ' % (i, i,)
    page_html_list.append(temp)

    if self.current_page >= self.all_pager:
    next_page = '

  • 下一页
    • '
    else:
    next_page = '
  • 下一页
    • ' % (self.current_page + 1,)
    page_html_list.append(next_page)

    last_page = '

  • 尾页
    • ' % (self.all_pager,)
    page_html_list.append(last_page)
    # 尾部添加标签
    page_html_list.append('''


''')
return ''.join(page_html_list)

分页器组件二

paging.py

  • from django.utils.safestring import mark_safe


class Paging:

    def __init__(self, total_count, per_page_count, per_page_page, current_page, data=None):
        """
        :param current_page:   当前页码
        :param total_count:    总数据量
        :param per_page_count:    每页显示多少条
        :param per_page_page:   总共显示多少个页码
        data: 可编辑Queryset对象

        start_page_number:起始页码
        end_page_number:结束页码
        """

        try:
            current_page = int(current_page)
        except Exception:
            current_page = 1

        half_number = per_page_page // 2
        a, b = divmod(total_count, per_page_count)
        # 如果余数不为0，页码总数为商+1
        if b:
            total_page_count = a + 1
        else:
            total_page_count = a
        # total_page_count 最大页数
        # 当当前页码小于等于0的时候，默认显示第一页
        if current_page >= total_page_count:
            current_page = total_page_count

        if current_page <= 0:
            current_page = 1

        # current_page 2
        # print(total_page_count)  # 2
        start_page_number = current_page - half_number  #
        end_page_number = current_page + half_number + 1  # 6

        if start_page_number <= 0:
            start_page_number = 1
            end_page_number = per_page_page + 1  # 7

        if end_page_number >= total_page_count:  # 6 > 2
            start_page_number = total_page_count - per_page_page + 1  # -4
            end_page_number = total_page_count + 1  # 3

        if total_page_count < per_page_page:
            start_page_number = 1
            end_page_number = total_page_count + 1

        self.current_page = current_page
        self.per_page_count = per_page_count
        self.total_page_count = total_page_count
        self.start_page_number = start_page_number
        self.end_page_number = end_page_number
        self.data = data

    @property
    def start_data_number(self):

        return (self.current_page - 1) * self.per_page_count

    @property
    def end_data_number(self):

        return self.current_page * self.per_page_count

    @property
    def paging_html(self):

        page_html = """
                   <nav aria-label="Page navigation">
                     <ul class="pagination">

                   """
        self.data["page"] = 1
        first_page = f"""
                       <li>
                         <a href="?{self.data.urlencode()}" aria-label="Previous">
                           <span aria-hidden="true">首页</span>
                         </a>
                       </li>"""
        page_html += first_page
        self.data['page'] = self.current_page - 1
        previous_page = f"""
                   <li>
                         <a href="?{self.data.urlencode()}" aria-label="Previous">
                           <span aria-hidden="true">&laquo;</span>
                         </a>
                       </li>"""
        page_html += previous_page

        for i in range(self.start_page_number, self.end_page_number):
            self.data['page'] = i
            if i == self.current_page:

                page_html += f'<li class="active"><a href="?{self.data.urlencode()}">{i}</a></li>'
            else:
                page_html += f'<li><a href="?{self.data.urlencode()}">{i}</a></li>'
        self.data['page'] = self.current_page + 1
        next_page = f"""
                       <li>
                             <a href="?{self.data.urlencode()}" aria-label="Next">
                               <span aria-hidden="true">&raquo;</span>
                             </a>
                           </li>
           """
        page_html += next_page
        self.data['page'] = self.total_page_count
        last_page = f"""
                           <li>
                             <a href="?{self.data.urlencode()}" aria-label="Previous">
                               <span aria-hidden="true">尾页</span>
                             </a>
                           </li>"""
        page_html += last_page

        page_html += """

                         </ul>
                       </nav>
                   """
        return mark_safe(page_html)

views

  • entry_obj = models.Enrollment.objects.all()
page = request.GET.get("page")	#当前页面

total_count = entry_obj.count()	#总数据数

per_page_count = 10				#每页显示数据条数

per_page_page = 7				#每页页码显示

data = copy.copy(request.GET)	#可编辑Queryset对象

page_obj = Paging(total_count, per_page_count, per_page_page, page, data)					  #实例化分页对象，参数是位置参数，一一对应

entry_obj=entry_obj[
page_obj.start_data_number:page_obj.end_data_number]
								#。。。。

page_html = page_obj.paging_html #生成分页HTML标签

bootstrap版分页器

class Pagination(object):
"""自定义分页（Bootstrap版）"""
def init(self, current_page, total_count, base_url, per_page=10, max_show=11):
"""
:param current_page: 当前请求的页码
:param total_count: 总数据量
:param base_url: 请求的URL
:param per_page: 每页显示的数据量，默认值为10
:param max_show: 页面上最多显示多少个页码，默认值为11
"""
try:
self.current_page = int(current_page)
except Exception as e:
# 取不到或者页码数不是数字都默认展示第1页
self.current_page = 1
# 定义每页显示多少条数据
self.per_page = per_page
# 计算出总页码数
total_page, more = divmod(total_count, per_page)
if more:
total_page += 1
self.total_page = total_page
# 定义页面上最多显示多少页码(为了左右对称，一般设为奇数)
self.max_show = max_show
self.half_show = max_show // 2
self.base_url = base_url

@property
def start(self):
return (self.current_page-1) * self.per_page

@property
def end(self):
return self.current_page * self.per_page

def page_html(self):
# 计算一下页面显示的页码范围
if self.total_page <= self.max_show: # 总页码数小于最大显示页码数
page_start = 1
page_end = self.total_page
elif self.current_page + self.half_show >= self.total_page: # 右边越界
page_end = self.total_page
page_start = self.total_page - self.max_show
elif self.current_page - self.half_show <= 1: # 左边越界
page_start = 1
page_end = self.max_show
else: # 正常页码区间
page_start = self.current_page - self.half_show
page_end = self.current_page + self.half_show
# 生成页面上显示的页码
page_html_list = []
page_html_list.append('

')
return "".join(page_html_list)

使用示例

def publisher_list(request):
# 从URL中取当前访问的页码数
current_page = int(request.GET.get('page'))
# 比len(models.Publisher.objects.all())更高效
total_count = models.Publisher.objects.count()
page_obj = Pagination(current_page, total_count, request.path_info)
data = models.Publisher.objects.all()[page_obj.start:page_obj.end]
page_html = page_obj.page_html()
return render(request, "publisher_list.html", {"publisher_list": data, "page_html": page_html})

posted @ 2019-12-17 11:40  阿浪阿浪  阅读(172)  评论(0)    收藏  举报