Django之分页器组件与自定义

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Django之分页器组件

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>'
                <ul class='pagination'>
            ''')
    first_page = '<li><a href="?page=%s">首页</a></li>' % (1)
    page_html_list.append(first_page)

    if self.current_page <= 1:
        prev_page = '<li class="disabled"><a href="#">上一页</a></li>'
    else:
        prev_page = '<li><a href="?page=%s">上一页</a></li>' % (self.current_page - 1,)

    page_html_list.append(prev_page)

    for i in range(pager_start, pager_end):
        if i == self.current_page:
            temp = '<li class="active"><a href="?page=%s">%s</a></li>' % (i, i,)
        else:
            temp = '<li><a href="?page=%s">%s</a></li>' % (i, i,)
        page_html_list.append(temp)

    if self.current_page >= self.all_pager:
        next_page = '<li class="disabled"><a href="#">下一页</a></li>'
    else:
        next_page = '<li><a href="?page=%s">下一页</a></li>' % (self.current_page + 1,)
    page_html_list.append(next_page)

    last_page = '<li><a href="?page=%s">尾页</a></li>' % (self.all_pager,)
    page_html_list.append(last_page)
    # 尾部添加标签
    page_html_list.append('''
                                       </nav>
                                       </ul>
                                   ''')
    return ''.join(page_html_list)
    

自定义分页器组件

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

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