Django框架学习笔记（19.自定义分页）

最新推荐文章于 2022-11-30 17:16:40 发布

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最新推荐文章于 2022-11-30 17:16:40 发布

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分类专栏： Django框架文章标签： django 前端

本文链接：https://blog.youkuaiyun.com/qq_41144008/article/details/78852052

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在讲自定义分页之前，先讲一个简单的。

在模板语言中还有一些特殊的存在，比如这个：

def tpl4(request):
    name = "asdf123456"
    return render(request, 'tpl4.html', {'name': name})

tpl4.html:

<body>
{{ name }}
{{ name|upper }}
</body>

运行后：

这些我们只需了解，但应该要学会自定义这种操作：

自定义simple_tag:

1.在某个app目录下创建一个名为templatetags文件夹（必须为这个名字）

2.在文件夹内创建py文件写入函数（任意取名）‘

3.写函数之前还有一个固定的格式，不能变，然后记得要在settings里面注册app

例：创建了一个st.py

from django import template
from django.utils.safestring import mark_safe
register = template.Library()
@register.simple_tag
def func(a1, a2):
    return a1 + a2

4.在html文件中固定格式：

{% load st %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
{% func 6 7 %}
</body>
</html>

这里就实现了一个加法功能。

自定义filter:

和上面这个差不过，不过它只能传2个参数：

from django import template
from django.utils.safestring import mark_safe
register = template.Library()
@register.filter
def func(a1, a2):
    return a1 + a2

html中：

<body>
{{ "fun"|func:"ction" }}
</body>

看似这种远不如上面那种好用，不过，它也有它的优点：

{% if "fun"|func:"ction" %}
{% endif %}

它可以用于if判断中，不过simple_tag不支持

自定义分页：

这里做一个简单的分页示例：

views.py加入：

LIST = []
for i in range(109):
    LIST.append(i)
    
def user_list(request):
    current_page = request.GET.get('p', 1)
    current_page = int(current_page)
    start = (current_page - 1) * 10
    end = current_page * 10
    data = LIST[start: end]
    all_count = len(LIST)
    count, y = divmod(all_count, 10)
    if y:
        count += 1
    page_list = []
    for i in range(1, count + 1):
        if i == current_page:
            temp = '<a class="page active" href="/user_list/?p=%s">%s</a>' % (i, i)
        else:
            temp = '<a class="page" href="/user_list/?p=%s">%s</a>' % (i, i)
        page_list.append(temp)
    from django.utils.safestring import mark_safe
    page_str = "".join(page_list)
    page_str = mark_safe(page_str)
    # 为了防止XSS攻击
    return render(request, 'user_list.html', {'li': data, 'page_str': page_str})

user_list.html:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .pagination .page{
            display: inline-block;
            padding: 5px;
            background-color: aqua;
            margin: 5px;
        }
        .pagination .active{
            background-color: brown;
            color: white;
        }
    </style>
</head>
<body>
<ul>
    {% for item in li %}
        {% include 'li.html' %}
    {% endfor %}
</ul>
<div class="pagination">
    {{ page_str }}
</div>
</body>
</html>

顺便用下上一篇的知识：

li.html:

<li>{{ item }}</li>

效果这样：

选中的那个会变成红色的。

这里做到了，但是如果数据过多，就显得不好了。

完善：

LIST = []
for i in range(1009):
    LIST.append(i)

def user_list(request):
    current_page = request.GET.get('p', 1)
    current_page = int(current_page)
    per_page_count = 10

    start = (current_page - 1) * per_page_count
    end = current_page * per_page_count
    data = LIST[start: end]
    all_count = len(LIST)
    total_count, y = divmod(all_count, per_page_count)
    if y:
        total_count += 1
    page_list = []
    page_num = 11
    if total_count <= page_num:
        start_index = 1
        end_index = total_count+1
    else:
        if current_page <= (page_num+1)/2:
            start_index = 1
            end_index = page_num+1
        else:
            start_index = current_page-(page_num-1)/2
            end_index = current_page+(page_num+1)/2
            if (current_page+(page_num-1)/2) > total_count:
                end_index = total_count+1
                start_index = total_count-(page_num-1)

    if int(current_page) == 1:
        prev = '<a class="page" href="javascript:void(0);">上一页</a>'
    else:
        prev = '<a class="page" href="/user_list/?p=%s">上一页</a>' % (current_page-1)
    page_list.append(prev)

    for i in range(int(start_index), int(end_index)):
        if i == current_page:
            temp = '<a class="page active" href="/user_list/?p=%s">%s</a>' % (i, i)
        else:
            temp = '<a class="page" href="/user_list/?p=%s">%s</a>' % (i, i)
        page_list.append(temp)


    if current_page == total_count:
        nex = '<a class="page" href="javascript:void(0);">下一页</a>'
    else:
        nex = '<a class="page" href="/user_list/?p=%s">下一页</a>' % (current_page+1)
    page_list.append(nex)

    jump = '''
    <input type="text"/><a οnclick='jumpTo(this, "/user_list/?p=");'>GO</a>
    <script>
        function jumpTo(ths,base){
             var val = ths.previousSibling.value;
             location.href = base + val;
        }
    </script>
    '''
    page_list.append(jump)

    from django.utils.safestring import mark_safe
    page_str = "".join(page_list)
    page_str = mark_safe(page_str)
    # 为了防止XSS攻击
    return render(request, 'user_list.html', {'li': data, 'page_str': page_str})

完善后的效果：

发现代码量很大，可以对它进行封装：

创一个utils文件夹，新建一个pagination.py

class Page:
    def __init__(self, current_page, data_count, per_page_count=10, page_num=7):
        self.current_page = current_page
        self.data_count = data_count
        self.per_page_count = per_page_count
        self.page_num = page_num

    def start(self):
        return (self.current_page - 1) * self.per_page_count

    def end(self):
        return self.current_page * self.per_page_count

    def all_count(self):
        v, y = divmod(self.data_count, self.per_page_count)
        if y:
            v += 1
        return v

    def page_str(self, base_url):
        page_list = []
        if self.all_count() <= self.page_num:
            start_index = 1
            end_index = self.all_count() + 1
        else:
            if self.current_page <= (self.page_num + 1) / 2:
                start_index = 1
                end_index = self.page_num + 1
            else:
                start_index = self.current_page - (self.page_num - 1) / 2
                end_index = self.current_page + (self.page_num + 1) / 2
                if (self.current_page + (self.page_num - 1) / 2) > self.all_count():
                    end_index = self.all_count() + 1
                    start_index = self.all_count() - (self.page_num - 1)

        if int(self.current_page) == 1:
            prev = '<a class="page" href="javascript:void(0);">上一页</a>'
        else:
            prev = '<a class="page" href="%s?p=%s">上一页</a>' % (base_url, self.current_page - 1)
        page_list.append(prev)

        for i in range(int(start_index), int(end_index)):
            if i == self.current_page:
                temp = '<a class="page active" href="%s?p=%s">%s</a>' % (base_url, i, i)
            else:
                temp = '<a class="page" href="%s?p=%s">%s</a>' % (base_url, i, i)
            page_list.append(temp)

        if self.current_page == self.all_count():
            nex = '<a class="page" href="javascript:void(0);">下一页</a>'
        else:
            nex = '<a class="page" href="%s?p=%s">下一页</a>' % (base_url, self.current_page + 1)
        page_list.append(nex)

        jump = '''
        <input type="text"/><a οnclick='jumpTo(this, "%s?p=");'>GO</a>
        <script>
            function jumpTo(ths,base){
                 var val = ths.previousSibling.value;
                 location.href = base + val;
            }
        </script>
        ''' % (base_url,)
        page_list.append(jump)

        from django.utils.safestring import mark_safe
        page_str = "".join(page_list)
        page_str = mark_safe(page_str)
        # 为了防止XSS攻击
        return page_str

在views.py里面这样写即可：

from utils import pagination

LIST = []
for i in range(1009):
    LIST.append(i)

def user_list(request):
    current_page = request.GET.get('p', 1)
    current_page = int(current_page)

    page_obj = pagination.Page(current_page, len(LIST))
    data = LIST[page_obj.start():page_obj.end()]
    page_str = page_obj.page_str("/user_list/")
    return render(request, 'user_list.html', {'li': data, 'page_str': page_str})