Django学习：分页优化(12)

当有很多页面时，页码会显得比较臃肿，需要将中间的页码隐藏起来，也就是需要对分页显示进行优化。

对之前的页面初步调整，之前分页页面未显示博客数量。

修改blog templates blog blog_list.html文件

<div class="panel-heading">{% block blog_list_title %}博客列表(一共有{{ page_of_blogs.paginator.count }}篇博客){% endblock %}</div>

此时可以正确显示博客数量。

修改views.py文件利于阅读

	context = {}
    context['blogs'] = page_of_blogs.object_list
    context['page_of_blogs'] = page_of_blogs
    context['blog_types'] = BlogType.objects.all()
    return render_to_response('blog/blog_list.html', context)

同时把blog_list.html的相应代码进行修改

<div class="panel-body">
					    {% for blog in blogs %}
					    <div class="blog">
					    	<h3><a href="{% url 'blog_detail' blog.pk %}">{{ blog.title }}</a></h3>
					    	<p class="blog_info">
					    		<span class="glyphicon glyphicon-tag"></span><a href='{% url "blogs_with_type" blog.blog_type.pk %}'>{{ blog.blog_type }}</a>
					    		<span class="glyphicon glyphicon-time"></span>{{ blog.created_time|date:"Y-m-d" }}
					    	</p>
							<p>{{ blog.content|truncatechars_html:120 }}</p>
					    </div>
						{% empty %}
						<div class="blog">
							<h3>-- 暂无博客，敬请期待 --</h3>
						</div>
						{% endfor %}
					</div>

---

将代码修改为以2篇博客作为分页

views.py

paginator = Paginator(blogs_all_list, 2)

此时刷新页面变为

产生2个需求，当用户点击页码时，让页码显示为高亮，另外减少显示的页码数量，增强用户观感体验。

• 让选中的页码显示高亮

  blog_list.html

{# 全部页码 #}
					    {% for page_num in page_of_blogs.paginator.page_range %}
					    	{% if page_num == page_of_blogs.number %}
								<li class='active'><a href="?page={{ page_num }}">{{ page_num }}</a></li>
					    	{% else %}
								<li><a href="?page={{ page_num }}">{{ page_num }}</a></li>
					    	{% endif %}
						{% endfor %}

此时选择页码会变为选中状态

为了点击一个页码时仅显示部分页面信息，可以考虑只显示出当前页及前后2页

• 修改views.py文件

def blog_list(request):
    
    blogs_all_list = Blog.objects.all()
    paginator = Paginator(blogs_all_list, 2) # 每10篇博客进行分页
    page_num = request.GET.get('page', 1) # 获取url的页面参数（GET请求）
    page_of_blogs = paginator.get_page(page_num)
    current_page_num = page_of_blogs.number # 获取当前页码
    page_range = [current_page_num - 2, current_page_num - 1, current_page_num, current_page_num + 1, current_page_num + 2]

    context = {}
    context['blogs'] = page_of_blogs.object_list
    context['page_range'] = page_range
    context['page_of_blogs'] = page_of_blogs
    context['blog_types'] = BlogType.objects.all()
    return render_to_response('blog/blog_list.html', context)

• 修改blog_list.html文件

{# 全部页码 #}
					    {% for page_num in page_range %}
					    	{% if page_num == page_of_blogs.number %}
								<li class='active'><span>{{ page_num }}</span></li>
					    	{% else %}
								<li><a href="?page={{ page_num }}">{{ page_num }}</a></li>
					    	{% endif %}
						{% endfor %}

此时得到的页面如下：

出现了一个新的问题，当页码已经是最后一页的时候，后两页页码显示了出来，但实际上是没有内容的。

对views.py文件进行优化

def blog_list(request):
    
    blogs_all_list = Blog.objects.all()
    paginator = Paginator(blogs_all_list, 2) # 每10篇博客进行分页
    page_num = request.GET.get('page', 1) # 获取url的页面参数（GET请求）
    page_of_blogs = paginator.get_page(page_num)
    current_page_num = page_of_blogs.number # 获取当前页码
    page_range = list(range(max(current_page_num - 2, 1), current_page_num)) + list(range(current_page_num, min(current_page_num + 2, paginator.num_pages) + 1))

    context = {}
    context['blogs'] = page_of_blogs.object_list
    context['page_range'] = page_range
    context['page_of_blogs'] = page_of_blogs
    context['blog_types'] = BlogType.objects.all()
    return render_to_response('blog/blog_list.html', context)

此时页面变为

• 继续修改views.py让首页和尾页显示出来

def blog_list(request):
    
    blogs_all_list = Blog.objects.all()
    paginator = Paginator(blogs_all_list, 2) # 每10篇博客进行分页
    page_num = request.GET.get('page', 1) # 获取url的页面参数（GET请求）
    page_of_blogs = paginator.get_page(page_num)
    current_page_num = page_of_blogs.number # 获取当前页码
    # 获取当前页前后各2页
    page_range = list(range(max(current_page_num - 2, 1), current_page_num)) + list(range(current_page_num, min(current_page_num + 2, paginator.num_pages) + 1))
    
    if page_range[0] != 1:
        page_range.insert(0, 1)
    if page_range[-1] != paginator.num_pages:
        page_range.append(paginator.num_pages)


    context = {}
    context['blogs'] = page_of_blogs.object_list
    context['page_range'] = page_range
    context['page_of_blogs'] = page_of_blogs
    context['blog_types'] = BlogType.objects.all()
    return render_to_response('blog/blog_list.html', context)

• 中间的页码用省略号显示

views.py

def blog_list(request):
    
    blogs_all_list = Blog.objects.all()
    paginator = Paginator(blogs_all_list, 2) # 每10篇博客进行分页
    page_num = request.GET.get('page', 1) # 获取url的页面参数（GET请求）
    page_of_blogs = paginator.get_page(page_num)
    current_page_num = page_of_blogs.number # 获取当前页码
    # 获取当前页前后各2页
    page_range = list(range(max(current_page_num - 2, 1), current_page_num)) + list(range(current_page_num, min(current_page_num + 2, paginator.num_pages) + 1))
    
    # 加上省略号
    if page_range[0] - 1 >= 2:
        page_range.insert(0, '...')
    if paginator.num_pages - page_range[-1] >= 2:
        page_range.append('...')


    # 加上首尾页码
    if page_range[0] != 1:
        page_range.insert(0, 1)
    if page_range[-1] != paginator.num_pages:
        page_range.append(paginator.num_pages)

    context = {}
    context['blogs'] = page_of_blogs.object_list
    context['page_range'] = page_range
    context['page_of_blogs'] = page_of_blogs
    context['blog_types'] = BlogType.objects.all()
    return render_to_response('blog/blog_list.html', context)

此时页面效果

此时...是可以点击的，可以通过修改blog_list.html模板文件调整为不可点击。

{# 全部页码 #}
					    {% for page_num in page_range %}
					    	{% if page_num == page_of_blogs.number %}
								<li class='active'><span>{{ page_num }}</span></li>
					    	{% else %}
					    		{% if page_num == '...' %}
					    			<li><span>{{ page_num }}</span></li>
					    		{% else %}
									<li><a href="?page={{ page_num }}">{{ page_num }}</a></li>
								{% endif %}
					    	{% endif %}
						{% endfor %}

进一步的美化操作，将博客数量显示在页码下方，并居中。

• 修改blog_list.html

<div class='paginator'>
					  <ul class="pagination">
					  	{# 上一页 #}
					    <li>
					    	{% if page_of_blogs.has_previous %}
						    	<a href="?page={{ page_of_blogs.previous_page_number }}" aria-label="Previous">
						        	<span aria-hidden="true">&laquo;</span>
						      	</a>
					    	{% else %}
					    		<span aria-hidden="true">&laquo;</span>
					    	{% endif %}
					    </li>
					    {# 全部页码 #}
					    {% for page_num in page_range %}
					    	{% if page_num == page_of_blogs.number %}
								<li class='active'><span>{{ page_num }}</span></li>
					    	{% else %}
					    		{% if page_num == '...' %}
					    			<li><span>{{ page_num }}</span></li>
					    		{% else %}
									<li><a href="?page={{ page_num }}">{{ page_num }}</a></li>
								{% endif %}
					    	{% endif %}
						{% endfor %}
					    {# 下一页 #}
					    <li>
					    	{% if page_of_blogs.has_next %}
						    	<a href="?page={{ page_of_blogs.next_page_number }}" aria-label="Next">
						        	<span aria-hidden="true">&raquo;</span>
						      	</a>
					    	{% else %}
					    		<span aria-hidden="true">&raquo;</span>
					    	{% endif %}
					    </li>
					  </ul>
					  <p>
					  	共有{{ page_of_blogs.paginator.count }}篇博客，当前{{ page_of_blogs.number }}页，共{{ page_of_blogs.paginator.num_pages }}页
					  </p>
				</div>

blog.css

ul.blog_types {
	list-style-type: none;
}
div.blog:not(:last-child) {
	margin-bottom: 2em;
	padding-bottom: 1em;
	border-bottom: 1px solid #eee;
}
div.blog h3 {
	margin-top: 0.5em;
}
div.blog p.blog-info {
	margin-bottom: 0;
}
div.paginator {
	text-align: center;
}

ul.blog_info_description {
	list-style-type: none;
	margin-bottom: 1em;
}
ul.blog_info_description li {
	display: inline-block;
	margin-right: 2em;
}
div.blog-content {
	text-indent: 2em;
}

强制刷新主页

还可以进一步优化让进入博客分类的页面显示效果与分页效果相同

views.py

from django.shortcuts import render_to_response,get_object_or_404
from django.core.paginator import Paginator
from .models import Blog, BlogType

# Create your views here.

# 每一页博客数量
each_page_blogs_number = 2

def blog_list(request):
    
    blogs_all_list = Blog.objects.all()
    paginator = Paginator(blogs_all_list, each_page_blogs_number) 
    page_num = request.GET.get('page', 1) # 获取url的页面参数（GET请求）
    page_of_blogs = paginator.get_page(page_num)
    current_page_num = page_of_blogs.number # 获取当前页码
    # 获取当前页前后各2页
    page_range = list(range(max(current_page_num - 2, 1), current_page_num)) + list(range(current_page_num, min(current_page_num + 2, paginator.num_pages) + 1))
    
    # 加上省略号
    if page_range[0] - 1 >= 2:
        page_range.insert(0, '...')
    if paginator.num_pages - page_range[-1] >= 2:
        page_range.append('...')

    # 加上首尾页码
    if page_range[0] != 1:
        page_range.insert(0, 1)
    if page_range[-1] != paginator.num_pages:
        page_range.append(paginator.num_pages)

    context = {}
    context['blogs'] = page_of_blogs.object_list
    context['page_range'] = page_range
    context['page_of_blogs'] = page_of_blogs
    context['blog_types'] = BlogType.objects.all()
    return render_to_response('blog/blog_list.html', context)

def blog_detail(request,blog_pk):
    context = {}
    context['blog'] = get_object_or_404(Blog, pk=blog_pk)
    return render_to_response('blog/blog_detail.html', context)

def blogs_with_type(request, blog_type_pk):
    context = {}
    blog_type = get_object_or_404(BlogType, pk=blog_type_pk)
    blogs_all_list = Blog.objects.filter(blog_type=blog_type)
    paginator = Paginator(blogs_all_list, each_page_blogs_number)
    page_num = request.GET.get('page', 1) # 获取url的页面参数（GET请求）
    page_of_blogs = paginator.get_page(page_num)
    current_page_num = page_of_blogs.number # 获取当前页码
    # 获取当前页前后各2页
    page_range = list(range(max(current_page_num - 2, 1), current_page_num)) + list(range(current_page_num, min(current_page_num + 2, paginator.num_pages) + 1))
    
    # 加上省略号
    if page_range[0] - 1 >= 2:
        page_range.insert(0, '...')
    if paginator.num_pages - page_range[-1] >= 2:
        page_range.append('...')

    # 加上首尾页码
    if page_range[0] != 1:
        page_range.insert(0, 1)
    if page_range[-1] != paginator.num_pages:
        page_range.append(paginator.num_pages)

    context = {}
    context['blog_type'] = blog_type
    context['blogs'] = page_of_blogs.object_list
    context['page_range'] = page_range
    context['page_of_blogs'] = page_of_blogs
    context['blog_types'] = BlogType.objects.all()
    return render_to_response('blog/blogs_with_type.html', context)

blogs_with_type.html

{% extends 'blog/blog_list.html' %}
{# 页面标题 #}
{% block title %}{{ blog_type.type_name }}{% endblock %}
{% block blog_list_title %}
	{{ blog_type.type_name }}
	<a href='{% url "blog_list" %}'>查看全部博客</a>
{% endblock %}

此时博客列表进入的页面如下：

对于分页的页码还可以使用全局设置，在settings.py中进行设置

settings.py

...
...
# 自定义设置
EACH_PAGE_BLOGS_NUMBER = 7

views.py

from django.conf import settings
def blog_list(request):
    
    blogs_all_list = Blog.objects.all()
    paginator = Paginator(blogs_all_list, settings.EACH_PAGE_BLOGS_NUMBER) 
    ....
    return render_to_response('blog/blog_list.html', context)
    
def blogs_with_type(request, blog_type_pk):
    context = {}
    blog_type = get_object_or_404(BlogType, pk=blog_type_pk)
    blogs_all_list = Blog.objects.filter(blog_type=blog_type)
    paginator = Paginator(blogs_all_list, settings.EACH_PAGE_BLOGS_NUMBER)
    ....

此时页面按每7篇进行一次分页。