30 Django分页组件

pager.py:

"""
如果想要使用分页，需要以下两个步骤

def xxx():
    queryset = models.Customer.objects.filter(active=1).select_related('level', 'creator')  # select_related主动跨表

    pager = Pagination(request, queryset)

    context = {
        'queryset': queryset[pager.start: pager.end],
        'pager_string': pager.html(),
    }
    return render(request, 'customer_list.html', context)

页面上：
{% for row in queryset %}
    {{row.id}}
    ...
{% endfor %}

<ul class="pagination">
    {{ pager_string }}
</ul>

"""

from django.utils.safestring import mark_safe


class Pagination(object):
    """分页"""

    def __init__(self, request, queryset, per_page_count=10):
        total_count = queryset.count()  # 总数据条数
        # 计算出总共有多少页面
        self.total_count = total_count
        self.total_page, div = divmod(total_count, per_page_count)
        if div:
            self.total_page += 1

        page = request.GET.get('page')

        if not page:
            page = 1
        else:
            if not page.isdecimal():
                page = 1
            else:
                page = int(page)
                if page < 0:
                    page = 1
                else:
                    if page > self.total_page:
                        page = self.total_page

        self.page = page
        self.per_page_count = per_page_count

        self.start = (page - 1) * per_page_count
        self.end = page * per_page_count

    def html(self):
        pager_list = []
        # 极值问题：总共的页码数量
        if self.total_page <= 11:
            start_page = 1
            end_page = self.total_page
        else:
            # 总页码比较多，判断当前页 <=6 : 1~11
            if self.page <= 6:
                start_page = 1
                end_page = 11
            else:
                if (self.page + 5) > self.total_page:
                    start_page = self.total_page - 10
                    end_page = self.total_page
                else:
                    start_page = self.page - 5
                    end_page = self.page + 5

        for i in range(start_page, end_page + 1):
            if i == self.page:
                item = '<li class="active"><a href="?page={}">{}</a></li>'.format(i, i)
            else:
                item = '<li><a href="?page={}">{}</a></li>'.format(i, i)
            pager_list.append(item)
        pager_string = mark_safe(''.join(pager_list))

        return pager_string