摘要：上一篇博客系統的博客還沒有實現評論，按標簽搜索按日期搜索按分類搜索的功能，這篇博客主要是對以上功能的增加。博客首頁修改主頁的文件有關分頁顯示的部分上一頁上一頁第頁共頁下一頁下一頁

上一篇‘博客系統’的博客還沒有實現評論，按標簽搜索、按日期搜索、按分類搜索的功能，這篇博客主要是對以上功能的增加。

第一步：新建app:comment，在主setting.py中添加新app,修改主urls.py文件

from django.conf.urls import url, include
from django.contrib import admin

urlpatterns = [
    url(r"^admin/", admin.site.urls),
    url(r"",include("blog.urls")),
    url(r"",include("comments.urls")),

]

第二步：編寫評論的數據庫表單

from django.contrib.auth.models import User
from django.db import models

# Create your models here.
from blog.models import Post


class Comment(models.Model):
    user =models.ForeignKey(User,verbose_name="用戶")
    email = models.EmailField(verbose_name="電子郵箱")
    text = models.TextField(max_length=255,verbose_name="評論正文")
    # auto_now_add=True 自動create_time為最新一次更改評論信息的時間
    create_time = models.DateTimeField(auto_now_add=True,verbose_name="創建時間")
    post = models.ForeignKey(Post)
    class Meta:
        verbose_name = "評論"
        verbose_name_plural = "評論"

    def __str__(self):
        return  self.text[:4]

第三步：編寫評論的路由comment.urls.py和comment.views.py

# comment.views.py
from django.shortcuts import render, get_object_or_404,redirect

# Create your views here.
from blog.models import Post
from comments.forms import CommentForm


def post_comment(request, id):
    # 1. 獲取用戶選擇的博客
    post = get_object_or_404(Post, id=id)
    # 2. 如果用戶提交評論
    if request.method == "POST":
        print(request.POST)
        form = CommentForm(request.POST)
        # 2.1 判斷表單是否合法
        if form.is_valid():
            comment = form.save(commit=False)
            comment.post = post
            comment.save()
        # 2.2 如果不合法，則提交錯誤信息
        else:
            return render(request, "blog/detail.html",
                          context={
                              "errors": form.errors
                          })
    # 3. 如果不是POST請求，訪問用戶詳情頁
    return redirect(post.get_url())

# comment.urls
from django.conf.urls import url, include
from django.contrib import admin

from comments import views

app_name = "comment"
urlpatterns = [
    url(r"^comment/blog/(?Pd+)/$",views.post_comment,name="post_comment"),
]

第四步：編寫評論表單

# 同步與數據庫評論的形式
from comments.models import Comment


class CommentForm(forms.ModelForm):
    class Meta:
        model = Comment
        fields = ["user","email","text"]

第五步：修改HTML文件中關于評論的部分

                        

                        
發表評論
                        

                            {% csrf_token %}
                            

                                

                                    {{ form.user.label }}
                                    {{ form.user }}
                                
                                

                                    {{ form.email.label }}
                                    {{ form.email }}
                                
                                

                                    {{ form.text.label }}
                                    {{ form.text }}
                                    發表
                                
                            
    
                        
                        

                            
評論列表，共 {{ comments.count }} 條評論
                            

                                {% for comment in comments %}
                                    

                                        {{ comment.user }}
                                        {{ comment.create_time }}
                                        

                                            {{ comment.text }}
                                        
                                    
                                {% endfor %}

                            
                        
                    

實現按標簽搜索、按日期搜索、按分類搜索的功能

第一步：自定義標簽

準備(必需)工作：

在某個app下創建一個名為templatetags(必需，且包名不可變)的包。假設我們在名為blog的app下創建了一個templatetags的包，并在該包下創建了一個名為blog_tags的文件.
 確保settings文件中的INSTALLD_APPS內必須含有該app
 修改setting.py有關時間顯示的部分

# TIME_ZONE = "UTC"
TIME_ZONE = "Asia/Shanghai"

USE_I18N = True

USE_L10N = True

#如果setting中配置USE_TZ=True則輸出的是UTC時間（naive time），
# 如果setting中配置USE_TZ=False，則該輸出時間與datetime.datetime.now()完全相同
# USE_TZ = True
USE_TZ = False

2. 接下來在blog_tags文件中寫入如下幾行

from django import template

register = template.Library()

 3. 在模板中使用{% load %} 標簽裝載自定義標簽或者裝飾器

from django import template
from django.db.models import Count

from blog.models import Post, Category, Tag

register = template.Library()

@register.simple_tag
def get_recent_posts(num=3):
    return Post.objects.all().order_by("-create_time")[:num]


@register.simple_tag
def archives():

    return Post.objects.dates(field_name="create_time",
                              kind="month",
                              order="DESC")

@register.simple_tag
def get_category():
    return Category.objects.annotate(num_posts=Count("post")).filter(num_posts__gt=0)


@register.simple_tag
def get_tags():
    # return Tag.objects.all()
    return Tag.objects.annotate(num_posts = Count("post"))

第二步： 編寫標簽查找的路由和視圖函數

路由

#blog.urls.py
from django.conf.urls import url

from django.contrib import admin

from blog import views

app_name = "blog"
urlpatterns = [
    url(r"^$", views.index, name="index"),
    url(r"blog/(?Pd+)/$", views.detail, name="detail"),
    url(r"^archive/(?Pd{4})/(?Pd{1,2})/", views.archive, name="archive"),
    url(r"^category/(?Pd+)/", views.category, name="category"),
    url(r"^tag/(?Pd+)/", views.tag, name="tag"),
    url(r"^search", views.search, name="search")
]

視圖函數

from django.db.models import Q
from django.http import HttpResponse
from django.shortcuts import render, get_object_or_404

# Create your views here.
from markdown import markdown

from blog.models import Post, Tag
from comments.forms import CommentForm


def index(request):
    # return HttpResponse("ok index!")
    posts = Post.objects.all()
    return render(request,"blog/index.html",context={
        "posts":posts
    })
def detail(request,id):
    # return HttpResponse("ok,%s detail" %(id))
    post = Post.objects.get(id=id)
    post.add_views()
    form = CommentForm()
    comments = post.comment_set.all()
    post.body = markdown(post.body,
                         extensions=["markdown.extensions.extra",
                                     "markdown.extensions.codehilite",
                                     "markdown.extensions.toc", ],
                         output_format="html")
    return render(request,"blog/detail.html",context={
        "post":post,
        "comments":comments,
        "form":form,
    })
def archive(request,year,month):
    posts = Post.objects.filter(
        create_time__year=year,
        create_time__month=month
    ).order_by("-create_time")

    return  render(request,"blog/index.html",context={
        "posts":posts
    })


def category(request,id):
    posts = Post.objects.filter(category_id=id)
    return render(request,"blog/index.html",
                  context={
                      "posts":posts

                  })


def tag(request,id):
    tag = get_object_or_404(Tag,id=id)
    posts = Post.objects.filter(tags=tag).order_by("-create_time")
    return render(
        request, "blog/index.html",
        context={
            "posts": posts

        }


    )


def search(request):
    query = request.GET.get("query",None)
    posts = Post.objects.filter(
        Q(title__icontains=query) |
        Q(body__icontains=query)
    )

    if not posts:
        return render(request,"blog/index.html",
                      context={
                          "posts":posts,
                          "message":"沒有找到相關信息"
                      }
                      )
    else:
        return render(request, "blog/index.html",
                      context={
                          "posts": posts

                      }
                      )

第三步：修改Html文件，僅截取部分代碼

這里在博客詳情頁需要顯示的是博客的結構(目錄)，添加顯示目錄的代碼
修改視圖函數

def detail(request,id):
    # return HttpResponse("ok,%s detail" %(id))
    post = Post.objects.get(id=id)
    post.add_views()
    form = CommentForm()
    comments = post.comment_set.all()
    # post.body = markdown(post.body,
    #                      extensions=["markdown.extensions.extra",
    #                                  "markdown.extensions.codehilite",
    #                                  "markdown.extensions.toc", ],
    #                      output_format="html")
    md = Markdown(
        extensions=["markdown.extensions.extra",
                    "markdown.extensions.codehilite",
                    "markdown.extensions.toc", ],
        output_format="html"
    )
    # Convert markdown to serialized XHTML or HTML.
    post.body = md.convert(post.body)
    post.toc = md.toc
    return render(request,"blog/detail.html",context={
        "post":post,
        "comments":comments,
        "form":form,

    })

右側導航欄

{#     基模板       #}

   

詳情頁添加博客目錄

{# blog/detail.html #}
{% block toc %}
    
文章目錄
        {{ post.toc | safe }}
    
{% endblock %}

按類別查找

按標簽查找

按時間查找

顯示博客目錄

Django提供了一個新的類來幫助你管理分頁數據，這個類存放在django/core/paginator.py.它可以接收列表、元組或其它可迭代的對象。

def index(request):
    all_posts = Post.objects.count()
    if all_posts % PER_PAGE != 0:
        page_nums = all_posts // PER_PAGE + 1
    else:
        page_nums = all_posts // PER_PAGE
    paginator = Paginator(Post.objects.all(),PER_PAGE)
    if  request.GET.get("page"):
        page = request.GET.get("page")
    else:
        page = 1
    try:
        posts = paginator.page(page)
    except (PageNotAnInteger,EmptyPage):
        posts = paginator.page(1)

        posts.has_previous()
        posts.has_next()
        posts.previous_page_number()
        posts.next_page_number()


    return render(request, "blog/index.html",
                  context={
        "title":"博客首頁",
        "posts":posts,
        "pages_num":page_nums,
    })

修改主頁的html文件有關分頁顯示的部分

  

            {% if posts.has_previous %}
                上一頁
            {% else %}
                上一頁

            {% endif %}


            第 {{ posts.number }} 頁 / 共 {{ pages_num }} 頁

            {% if posts.has_next %}
                下一頁

            {% else %}
                下一頁