Django 搜索和Readmore与RSS和分页

Django 搜索和Readmore与RSS和分页

搜索和ReadMore

搜索功能

搜索功能的实现设计:

• 前端界面输入搜索关键字, 传送到对应view中
• 在对应的view中进行数据库关键字搜索

这里搜索可以只对文章名搜索或者全文搜索，首先在my_blog/templates下添加所有输入框,在base.html中，对侧边栏的代码进行如下的修改。

<div class="sidebar pure-u-1 pure-u-md-1-4">
        <div class="header">
            <h1 class="brand-title"><a href="{% url "home" %}">Andrew Liu Blog</a></h1>
            <h2 class="brand-tagline">Snow Memory</h2>
            <nav class="nav">
                <ul class="nav-list">
                    <li class="nav-item">
                        <a class="button-success pure-button" href="/">Home</a>
                    </li>
                    <li class="nav-item">
                        <a class="button-success pure-button" href="{% url "archives" %}">Archives</a>
                    </li>
                    <li class="nav-item">
                        <a class="pure-button" href="https://github.com/Andrew-liu/my_blog_tutorial">Github</a>
                    </li>
                    <li class="nav-item">
                        <a class="button-error pure-button" href="http://weibo.com/dinosaurliu">Weibo</a>
                    </li>
                    <li class="nav-item">
                        <a class="button-success pure-button" href="/">Pages</a>
                    </li>
                    <li class="nav-item">
                        <a class="button-success pure-button" href="{% url "about_me" %}">About Me</a>
                    </li>
                    <li>
                    <form class="pure-form" action="/search/" method="get">
                    <input class="pure-input-3-3" type="text" name="s" placeholder="search">
                    </form>
                    </li>
                </ul>
            </nav>
        </div>
    </div>

在my_blog/article/views.py中添加查询逻辑

def blog_search(request):
    if 's' in request.GET:
        s = request.GET['s']
        if not s:
            return render(request,'home.html')
        else:
            post_list = Article.objects.filter(title__icontains = s)
            if len(post_list) == 0 :
                return render(request,'archives.html', {'post_list' : post_list,
                                                    'error' : True})
            else :
                return render(request,'archives.html', {'post_list' : post_list,
                                                    'error' : False})
    return redirect('/')

这里为了简单起见, 直接对archives.html进行修改, 使其符合查询逻辑

{% extends "base.html" %}

{% block content %}
<div class="posts">
    {% if error %}
        <h2 class="post-title">NOT Found</a></h2>
    {% else %}
    {% for post in post_list %}
        <section class="post">
            <header class="post-header">
                <h2 class="post-title"><a href="{% url "detail" id=post.id %}">{{ post.title }}</a></h2>

                    <p class="post-meta">
                        Time:  <a class="post-author" href="#">{{ post.date_time |date:"Y /m /d"}}</a> <a class="post-category post-category-js" href="{% url "search_tag" tag=post.category %}">{{ post.category }}</a>
                    </p>
            </header>
        </section>
    {% endfor %}
    {% endif %}
</div><!-- /.blog-post -->
{% endblock %}

添加了if判断逻辑, 然后还需要修改views中的archives

def archives(request) :
    try:
        post_list = Article.objects.all()
    except Article.DoesNotExist :
        raise Http404
    return render(request, 'archives.html', {'post_list' : post_list, 
                                            'error' : False})

最后添加my_blog/my_blog/urls.py设置url

urlpatterns = [
    # Examples:
    # url(r'^$', 'my_blog.views.home', name='home'),
    # url(r'^blog/', include('blog.urls')),

    url(r'^admin/', include(admin.site.urls)),
    url(r'^$', views.home, name = 'home'),
    url(r'^(?P<id>\d+)/$', views.detail, name='detail'),
    url(r'^archives/$', views.archives, name = 'archives'),
    url(r'^aboutme/$', views.about_me, name = 'about_me'),
    url(r'^tag(?P<tag>\w+)/$', views.search_tag, name = 'search_tag'),
    url(r'^search/$',views.blog_search, name = 'search'),
]

最终效果。

ReadMore功能

对于ReadMore的前段按钮界面设置早已经添加过了, 所以这里只需要进行简单的设置就好了

通过使用Django中内建的filter就可以速度实现

{{ value|truncatewords:2 }} #这里2表示要显示的单词数, 以后的会被截断, 不在显示
这里只需要修改my_blog/templates/home.html界面中的变量的过滤器

#将正文截断设置为10
 {{ post.content|custom_markdown|truncatewords_html:20 }}

在浏览器中输入http://localhost:9000/可以看到效果(最好把博文设置的长一些)

RSS和分页

RSS功能

Django是一个全面型框架, 很多功能都可以直接找到, 对于RSS功能, 可以从其中的高层框架的聚合Feed框架中找到(The syndication feed framework)

上层Feed生成框架可以直接应用Feed类, 我们可以直接继承Feed在其中定义自己的方法

在my_blog/article/views.py中定义类:

from django.contrib.syndication.views import Feed  #注意加入import语句


class RSSFeed(Feed) :
    title = "RSS feed - article"
    link = "feeds/posts/"
    description = "RSS feed - blog posts"

    def items(self):
        return Article.objects.order_by('-date_time')

    def item_title(self, item):
        return item.title

    def item_pubdate(self, item):
        return item.date_time

    def item_description(self, item):
        return item.content

然后在my_blog/article/models.py中重写get_absolute_url方法

from django.db import models
from django.core.urlresolvers import reverse

# Create your models here.
class Article(models.Model) :
    title = models.CharField(max_length = 100)  #博客题目
    category = models.CharField(max_length = 50, blank = True)  #博客标签
    date_time = models.DateTimeField(auto_now_add = True)  #博客日期
    content = models.TextField(blank = True, null = True)  #博客文章正文

 #获取URL并转换成url的表示格式
    def get_absolute_url(self):
        path = reverse('detail', kwargs={'id':self.id})
        return "http://127.0.0.1:8000%s" % path

    def __str__(self) :
        return self.title

    class Meta:
        ordering = ['-date_time']

之后在my_blog/my_blog/urls.py中设置对应的url

from django.conf.urls import url
from django.contrib import admin
from article import views
from article.views import RSSFeed

urlpatterns = [
    # Examples:
    # url(r'^$', 'my_blog.views.home', name='home'),
    # url(r'^blog/', include('blog.urls')),

    url(r'^admin/', admin.site.urls),
    url(r'^$', views.home', name = 'home'),
    url(r'^(?P<id>\d+)/$', views.detail', name='detail'),
    url(r'^archives/$', views.archives', name = 'archives'),
    url(r'^aboutme/$', views.about_me', name = 'about_me'),
    url(r'^tag(?P<tag>\w+)/$', views.search_tag', name = 'search_tag'),
    url(r'^search/$',views.blog_search', name = 'search'),
    url(r'^feed/$', RSSFeed(), name = "RSS"),  #新添加的urlconf, 并将name设置为RSS, 方便在模板中使用url
]

下面修改my_blog/templates/base.html, 在其中添加RSS按钮

<!doctype html>
<html lang="en">
<head>
    <meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="description" content="A layout example that shows off a blog page with a list of posts.">

    <title>{% block title %} Andrew Liu Blog {% endblock %}</title>
    <link rel="stylesheet" href="http://labfile.oss.aliyuncs.com/courses/487/pure-min.css">
    <link rel="stylesheet" href="http://labfile.oss.aliyuncs.com/courses/487/grids-responsive-min.css">
    <link rel="stylesheet" href="http://labfile.oss.aliyuncs.com/courses/487/blog.css">
    <link rel="stylesheet" href="http://picturebag.qiniudn.com/monokai.css">
</head>
<body>
<div id="layout" class="pure-g">
    <div class="sidebar pure-u-1 pure-u-md-1-4">
        <div class="header">
            <h1 class="brand-title"><a href="{% url "home" %}">Andrew Liu Blog</a></h1>
            <h2 class="brand-tagline">Snow Memory</h2>
            <nav class="nav">
                <ul class="nav-list">
                    <li class="nav-item">
                        <a class="button-success pure-button" href="/">Home</a>
                    </li>
                    <li class="nav-item">
                        <a class="button-success pure-button" href="{% url "archives" %}">Archives/a>
                    </li>
                    <li class="nav-item">
                        <a class="pure-button" href="https://github.com/Andrew-liu/my_blog_tutorial">Github</a>
                    </li>
                    <li class="nav-item">
                        <a class="button-error pure-button" href="http://weibo.com/dinosaurliu">Weibo</a>
                    </li>
                    <li class="nav-item">
                        <a class="button-success pure-button" href="/">Pages</a>
                    </li>
                    <li>
                    <form class="pure-form" action="/search/" method="get">
                    <input class="pure-input-3-3" type="text" name="s" placeholder="search">
                    </form>
                    </li>
                    <li class="nav-item">
                        <a class="button-success pure-button" href="{% url "about_me" %}">About Me</a>
                    </li>
                    <li class="nav-item">
                        <a class="button-success pure-button" href="{% url "RSS" %}">RSS</a>  
                    </li>
                </ul>
            </nav>
        </div>
    </div>


    <div class="content pure-u-1 pure-u-md-3-4">
        <div>
            {% block content %}
            {% endblock %}
            <div class="footer">
                <div class="pure-menu pure-menu-horizontal pure-menu-open">
                    <ul>
                        <li><a href="http://andrewliu.tk/about/">About Me</a></li>
                        <li><a href="http://twitter.com/yuilibrary/">Twitter</a></li>
                        <li><a href="http://github.com/yahoo/pure/">GitHub</a></li>
                    </ul>
                </div>
            </div>
        </div>
    </div>
</div>


</body>
</html>

保存后, 在浏览器中输入http://localhost:9000/可以看到新增的RSS按钮, 点击看以看到对应的效果。

更多功能可以查看The syndication feed framework官方文档

分页功能

当博客文章较多的时候, 我们并不希望以此在主页上显示全部的博客文章, 而是希望能够每页显示固定的文章数目, 这样既能提高性能, 也能提高美观度, 何乐而不为呢?

现在这一章节来看看怎么实现分页功能

• 首先添加包
• 重写home方法
• 修改模板

修改my_blog/article/views.py中的home函数

from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger  #添加包

def home(request):
    posts = Article.objects.all()  #获取全部的Article对象
    paginator = Paginator(posts, 2) #每页显示两个
    page = request.GET.get('page')
    try :
        post_list = paginator.page(page)
    except PageNotAnInteger :
        post_list = paginator.page(1)
    except EmptyPage :
        post_list = paginator.paginator(paginator.num_pages)
    return render(request, 'home.html', {'post_list' : post_list})

修改my_blog/templates下的home.html

{% extends "base.html" %}

{% load custom_markdown %}
{% block content %}
<div class="posts">
    {% for post in post_list %}
        <section class="post">
            <header class="post-header">
                <h2 class="post-title"><a href="{% url "detail" id=post.id %}">{{ post.title }}</a></h2>

                    <p class="post-meta">
                        Time:  <a class="post-author" href="#">{{ post.date_time |date:"Y M d"}}</a> <a class="post-category post-category-js" href="{% url "search_tag" tag=post.category %}">{{ post.category|title }}</a>
                    </p>
            </header>

                <div class="post-description">
                    <p>
                        {{ post.content|custom_markdown|truncatewords:10 }}
                    </p>
                </div>
                <a class="pure-button" href="{% url "detail" id=post.id %}">Read More >>> </a>
        </section>
    {% endfor %}

    {% if post_list.object_list and post_list.paginator.num_pages > 1 %}
      <div>
      <ul class="pager">
      {% if post_list.has_previous %}
        <li><a href="?page={{ post_list.previous_page_number }}">Pre Page</a></li>
      {% endif %}

      {% if post_list.has_next %}
        <li><a href="?page={{ post_list.next_page_number }}">Next Page</a></li>
      {% endif %}
      </ul>
      </div>
    {% endif %}
</div><!-- /.blog-post -->
{% endblock %}

我设置的是每页显示两篇博文, 可以修改成其他数值

更多细节可以查看pagination官方文档

保存后, 在浏览器中输入http://localhost:9000/可以看到新增的下一页按钮(博客文章要多加几篇), 点击看以看到对应的效果

到目前为止, 博客的基本功能都实现了, 下一篇我们将讲到怎么在云端进行部署

最后我们把整个blog更新到github仓库中

$  git add .  #添加全部更新到暂存区
$  git commit -m "rss and paginator"  #提交到git
[master b53356b] rss and paginator
 2 files changed, 24 insertions(+), 1 deletion(-)
$  git push  #提交到github中