django之分頁,純python代碼

時間 2019-12-14

原文原文鏈接

Django中分頁

py文件代碼

"""
自定義分頁組件
能夠返回分頁的數據和分頁的HTML代碼
"""
from django.http import QueryDict


class Pagination(object):

    def __init__(self, current_page, total_count, url_prefix, query_dict=QueryDict(mutable=True), per_page=10,
                 show_page=9):
        """
        初始化分分頁器
        :param url_prefix: a標籤的URL前綴
        :param current_page: 當前頁碼數
        :param total_count: 數據總數
        :param query_dict: 空的QueryDict()對象，而且是可修改的
        :param per_page: 每一頁顯示多少數據， 默認值是10
        :param show_page: 頁面顯示的頁碼數， 默認值是9
        """
        # 0.分頁的URL前綴
        self.url_prefix = url_prefix
        self.query_dict = query_dict
        # 1. 每一頁顯示10條數據
        self.per_page = per_page
        assert per_page > 0
        # 2. 計算須要多少頁
        total_page, more = divmod(total_count, per_page)
        if more:
            total_page += 1
        self.total_page = total_page
        # 3. 當前頁碼
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1
        current_page = total_page if current_page > total_page else current_page
        # 頁碼必須是大於0的數
        if current_page < 1:
            current_page = 1

        self.current_page = current_page
        # 4. 頁面最多顯示的頁碼數
        self.show_page = show_page
        # 5. 最多顯示頁碼的一半
        self.half_show_page = self.show_page // 2

    @property
    def start(self):
        # 數據切片的開始位置
        return self.per_page * (self.current_page - 1)

    @property
    def end(self):
        # 數據切片的結束爲止
        return self.current_page * self.per_page

    # 定義一個返回HTML代碼的方法
    def page_html(self):
        # 若是總頁碼數小於最大要顯示的頁碼數
        if self.total_page < self.show_page:
            show_page_start = 1
            show_page_end = self.total_page
        # 左邊越界
        elif self.current_page - self.half_show_page < 1:
            show_page_start = 1
            show_page_end = self.show_page
        # 右邊越界
        elif self.current_page + self.half_show_page > self.total_page:
            show_page_end = self.total_page
            show_page_start = self.total_page - self.show_page + 1
        else:
            show_page_start = self.current_page - self.half_show_page
            # 頁面顯示頁碼的結束
            show_page_end = self.current_page + self.half_show_page
        # 生成分頁的HTML代碼
        page_list = []
        # 添加分頁代碼的前綴
        page_list.append('<nav aria-label="Page navigation"><ul class="pagination">')
        # 添加首頁
        self.query_dict['page'] = 1
        page_list.append(f'<li><a href="{self.url_prefix}?{self.query_dict.urlencode()}">首頁</a></li>')
        # 添加上一頁
        if self.current_page - 1 < 1:  # 已經到頭啦，不讓點上一頁啦
            page_list.append(
                '<li class="disabled"><a href="" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a></li>')
        else:
            self.query_dict['page'] = self.current_page - 1
            page_list.append(
                f'<li><a href="{self.url_prefix}?{self.query_dict.urlencode()}" aria-label="Previous">'
                f'<span aria-hidden="true">&laquo;</span></a></li>'
            )
        for i in range(show_page_start, show_page_end + 1):
            self.query_dict['page'] = i
            if i == self.current_page:
                s = f'<li class="active"><a href="{self.url_prefix}?{self.query_dict.urlencode()}">{i}</a></li>'
            else:
                s = f'<li><a href="{self.url_prefix}?{self.query_dict.urlencode()}">{i}</a></li>'
            page_list.append(s)
        # 添加下一頁
        if self.current_page + 1 > self.total_page:
            page_list.append(
                '<li class="disabled"><a href="" aria-label="Next"><span aria-hidden="true">&raquo;</span></a></li>')
        else:
            self.query_dict['page'] = self.current_page + 1
            page_list.append(
                f'<li><a href="{self.url_prefix}?{self.query_dict.urlencode()}" aria-label="Next">'
                f'<span aria-hidden="true">&raquo;</span></a></li>'
            )
        # 添加尾頁
        self.query_dict['page'] = self.total_page
        page_list.append(f'<li><a href="{self.url_prefix}?{self.query_dict.urlencode()}">尾頁</a></li>')
        # 添加分頁代碼的後綴
        page_list.append('</ul></nav>')
        page_html = ''.join(page_list)
        return page_html

實例化對象

def dashboard(request):
    # 獲取當前網頁路徑
    url_prefix = request.path_info
    # 獲取當前頁碼數
    current_page = request.GET.get('page', 1)
    # 獲取全部客戶的信息
    customer_list = Customer.objects.all()
    # 實例分頁代碼
    pagination = Pagination(current_page=current_page, total_count=customer_list.count(), url_prefix=url_prefix, per_page=8)
    # 獲取當前頁的數據
    data = customer_list[pagination.start:pagination.end]
    page_html = pagination.page_html()
    return render(request, "Dashboard.html", {'customer_list': data, "page_html": page_html})