dgango-博客项目之点赞与评论

傷城~ 2021-09-20 05:10 196阅读 0赞

一、点赞和踩灭

1、事务

事务：要么同时发生，要么同时不发生，文章点赞表增加一条数据的时候，对应的文章的点赞或者踩灭数加1，如果后面的if语句不能执行，则根据事务，点赞表也不会增加数据

from django.db import transaction                                                         #引入transaction事务
    
    with transaction.atomic():
        obj = ArticleUpDown.objects.create(user_id=user_pk, article_id=article_id, is_up=is_up)    #文章点赞表里面添加一条数据
        if is_up:
            Article.objects.filter(pk=article_id).update(up_count=F("up_count") + 1)            #文章表相应的文章的点赞数加1
        else:
            Article.objects.filter(pk=article_id).update(down_count=F("down_count") + 1)       #文章表相应的文章的踩灭数加1

2、render方法

浏览器给服务器发送一个请求，视图函数从模板中取到html页面，如果页面里面有模板语法，如\{ \{ \}\}、\{% %\}，render方法会先对其进行渲染，将模板语法替换为相应的html标签，

最后将标签返回给浏览器，所以如果js在html页面，那么就可以使用模板语法，而如果将js单独做成一个静态文件，则不能使用模板语法。

3、点赞的视图函数和页面

views.py文件增加点赞视图：

import json
    from django.http import JsonResponse
    from django.db.models import F
    from django.db import transaction
    def digg(request):
        res={"state":True}                     #状态为true代表点赞，false为踩灭
        user_pk=request.user.pk                 # 当前登录用户，即点赞用户，request.user是全局变量
        article_id=request.POST.get("article_id")
        is_up=request.POST.get("is_up")             #因为js默认post是urlencode，发送的是字符串，所以这里接收到的就是字符串
        is_up=json.loads(is_up)                #将收到的字符串通过json序列化为我们需要的布尔值
        try:
            with transaction.atomic():          #事务
                obj=ArticleUpDown.objects.create(user_id=user_pk,article_id=article_id,is_up=is_up)
                if is_up:
                     Article.objects.filter(pk=article_id).update(up_count=F("up_count")+1)
                else:
                     Article.objects.filter(pk=article_id).update(down_count=F("down_count") + 1)
        except Exception as e:
            res["state"]=False                #变成踩灭状态
            res["first_action"]=ArticleUpDown.objects.filter(user_id=user_pk,article_id=article_id).first().is_up  #返回给ajax的数据多了first_action属性
        return JsonResponse(res)                   #返回给ajax的时候，ajax不用反序列化，接收到的是一个字典格式

article\_detail.html页面：

{% extends "base.html" %}
    
    {% block content %}
        <h3 class="text-center">{
         { article_obj.title }}</h3>
        <div class="article_content">
            {
         { article_obj.articledetail.content|safe }}
        </div>
        <div class="poll clearfix">
            <div id="div_digg" class="clearfix">
                <div class="diggit action">
                    <span class="diggnum" id="digg_count">{
         { article_obj.up_count }}</span>
                </div>
                <div class="buryit action">
                    <span class="burynum" id="bury_count">{
         { article_obj.down_count }}</span>
                </div>
                <div class="clear"></div>
            </div>
        </div>
        <div class="diggword" id="digg_tips" style="color: red;"></div>
        <div class="info" article_id="{
         { article_obj.pk }}" username="{
         { request.user.username }}"></div>     {#为了在静态文件article_detail.js中取到html页面的变量#}
        {% csrf_token %}
        <script src="/static/js/article_detail.js"></script>
    {% endblock %}
    
    
    因为我们的html是继承的base.html页面，所有要在base.html页面引入
    <link rel="stylesheet" href="/static/css/article_detail.css">

article\_detail.css样式代码：

#div_digg {
        float: right;
        margin-bottom: 10px;
        margin-right: 30px;
        font-size: 12px;
        width: 125px;
        text-align: center;
        margin-top: 10px;
    }
    .diggit {
        float: left;
        width: 46px;
        height: 52px;
        background: url('/static/img/upup.gif') no-repeat;        /*引用的网站的图片会因为网站做的防盗链而使图片无妨访问，所以要把图片下载到本地*/
        text-align: center;
        cursor: pointer;
        margin-top: 2px;
        padding-top: 5px;
    }
    .buryit {
        float: right;
        margin-left: 20px;
        width: 46px;
        height: 52px;
        background: url('/static/img/downdown.gif') no-repeat;
        text-align: center;
        cursor: pointer;
        margin-top: 2px;
        padding-top: 5px;
    }
    .clear {
        clear: both;
    }

article\_detail.js代码：

$(".action").click(function () {
        if ($(".info").attr("username")) {                                      //表示当前用户登录
            var is_up;
            is_up = $(this).hasClass("diggit");
            article_id = $(".info").attr("article_id");                            //根据属性查找取到article_detail.html页面article_id的值
            //
            $.ajax({
                url: "blog/digg/",
                type: "post",
                data: {
                    is_up: is_up,
                    article_id: article_id,
                    csrfmiddlewaretoken: $("[name='csrfmiddlewaretoken']").val()     //防止出现404 forbidden错误
                },
                success: function (data) {
                    if (data.state) {               // 点赞或者踩灭成功
                        if (is_up) {                // 点赞成功
                            var val = $("#digg_count").text();
                            val = parseInt(val) + 1;
                            $("#digg_count").text(val);
                        }
                        else {                      // 踩灭成功
                            var val = $("#bury_count").text();
                            val = parseInt(val) + 1;
                            $("#bury_count").text(val);
                        }
                    }
                    else {                          //重复提交
                        console.log(data.first_action);
                        if (data.first_action) {
                            $("#digg_tips").html("您已经推荐过了");
                            setTimeout(function () {                        // 1秒后下面的消息不显示
                                $("#digg_tips").html("");
                            }, 1000)
                        }
                        else {
                            $("#digg_tips").html("您已经反对过了");
                            setTimeout(function () {
                                $("#digg_tips").html("");
                            }, 1000)
                        }
                    }
                }
            })
        }
        else{                                                          //用户必须登录后才能进行点赞、踩灭
            # var s="<a href='/login/' class='pull-right'>请登陆！</a>";
            # $("#div_digg").after(s);                                 //返回给用户“请登陆”信息
            location.href = "/login/?next=" + location.pathname       //直接调转到用户登录页面
        }
    });

二、评论

1、js取标签里的值

select标签                .val();
    input标签                 .val();
    textarea标签              .val();
    div标签、span标签取里面值的时候用.html()或.text();

2、评论楼：

article\_detail.html页面：

{% extends "base.html" %}
    
    {% block content %}
        <h3 class="text-center">{
         { article_obj.title }}</h3>
        <div class="article_content">
            {
         { article_obj.articledetail.content|safe }}
        </div>
        <ul class="comment_list list-group">
            评论楼：
            {% for comment in comment_list %}
                <li class="comment_item list-group-item">
                    <div>
                        <a href="">#{
         { forloop.counter }}</a>楼    
                        <span>{
         { comment.create_time|date:"Y-m-d H:i" }}</span>                      {#显示时间，格式为年-月-日 时:分#}
                        <span>{
         { comment.user.username }}</span>                                               {#评论人，当前评论的评论名#}
                        <a class="pull-right reply_btn" username="{
         { comment.user.username }}"
                           comment_id="{
         { comment.pk }}"><span>回复</span></a>
                    </div>
                    {% if comment.parent_comment_id %}                                                           {#评论是子评论#}
                            <div class="parent_comment_infon well">
                                 @{
         { comment.parent_comment.user.username }} : {
         { comment.parent_comment.content }}<br/>
                                 {
         { comment.content }}
                            </div>
                    {% else %}                                                                                {#评论是根评论#}
                            <div class="comment_con">
                                <p>{
         { comment.content }}</p>
                            </div>
                    {% endif %}
                </li>
            {% endfor %}
        </ul>
        <div class="comment">
            <div>
                昵称：
                <input type="text" id="tbCommentAuthor" class="author" disabled="disabled" size="50"
                       value="{
         { request.user.username }}">
            </div>
            <div>
                <p>评论内容</p>
                <textarea name="" id="comment_content" cols="115" rows="10"></textarea>
            </div>
            <button class="btn  btn-default comment_btn">提交</button>
        </div>
        <div class="info" article_id="{
         { article_obj.pk }}" username="{
         { request.user.username }}"></div>
        {% csrf_token %}
        <script>
            var pid = "";
            $(".comment_btn").click(function () {                           // 提交评论事件
                article_id = $(".info").attr("article_id");                //在页面根据属性查找得到当前文章id号
                content = $("#comment_content").val();                    //textarea标签通过.val()得到里面的值
                // 处理文本框内容
                if (pid) {
                    var index = content.indexOf("\n");                      //得到\n换行符的索引
                    content = content.slice(index + 1)                       //换行符的索引加1的位置即我们所需要文本内容的开始位置
                }
                $.ajax({
                    url: "/blog/comment/",
                    type: "post",
                    data: {
                        article_id: article_id,
                        content: content,
                        pid: pid,                                        //pid为空，则提交根评论
                        csrfmiddlewaretoken: $("[name='csrfmiddlewaretoken']").val()
                    },
                    success: function (data) {                          //视图函数comment返回的数据
                        console.log(data);
                        ctime = data.ctime;
                        content = data.content;
                        username = $(".info").attr("username");       //从页面取到评论人的名字
                        s = '<li class="comment_item list-group-item temp"> <div> <span>' + ctime + '</span>  <span>' + username + '</span> </div> <div class="comment_con"><p>' + content + '</p></div> </li>'
                        $(".comment_list").append(s);
                        $("#comment_content").val("");                //提交成功后，清空评论框里面的评论内容
                        pid = "";                                         //pid重新置空，这样接着在评论框里评论就变成了根评论，否则提交一直是子评论
                    }
                })
            });
            $(".reply_btn").click(function () {                    // 回复按钮事件
                $("#comment_content").focus();                     // 获取输入框的焦点
                var val = "@" + $(this).attr("username") + "\n";
                $("#comment_content").val(val);
                pid = $(this).attr("comment_id")
            })
        </script>
        <script src="/static/js/article_detail.js"></script>
    {% endblock %}

article\_detail.css代码：

input.author {
        background-image: url("/static/img/icon_form.gif");
        background-repeat: no-repeat;
        border: 1px solid #ccc;
        padding: 4px 4px 4px 30px;
        width: 300px;
        font-size: 13px;
    }
    .comment_item .comment_con{
        margin-top: 10px;
        margin-left: 20px;
    }
    .conmment_item{
        margin-left: 20px;
    }
    .comment {
        width: 820px;
    }
    .parent_comment_infon{
        position: relative;
        margin: 0 40px 0 40px;
        border: #ccc 1px dashed;
        padding: 1px;
        color: grey;
        font-family: Arial,Helvetica,sans-serif;
        font-size: 12px;
        font-weight: normal;
        text-decoration: none;
    }
    .comment_con{
        position: relative;
        margin: 0 10px 0 10px;
        border: #ccc 1px dashed;
        padding: 5px;
        color: black;
        font-family: Arial,Helvetica,sans-serif;
        font-size: 15px;
        font-weight: normal;
        text-decoration: none;
    }
    .temp {
        background-color: gainsboro;
    }

views.py文件增加评论楼视图：

# 评论
    def comment(request):
        user_pk=request.user.pk
        article_id=request.POST.get("article_id")
        content=request.POST.get("content")
        pid=request.POST.get("pid")
        response={}
        with transaction.atomic():                   #事件
            if not pid:                              # pid为空表示根评论
                comment_obj=Comment.objects.create(user_id=user_pk,article_id=article_id,content=content)                          # 提交根评论
            else:                                     # 子评论
                comment_obj = Comment.objects.create(user_id=user_pk, article_id=article_id, content=content,parent_comment_id=pid)  # 提交子评论
            Article.objects.filter(pk=article_id).update(comment_count=F("comment_count")+1)
        response["ctime"]=comment_obj.create_time.strftime("%Y-%m-%d %H:%M")           #返回给ajax的创建时间，时间格式为%Y-%m-%d %H:%M
        response["content"]=comment_obj.content                                          #返回给ajax的评论内容
        return JsonResponse(response)
    def article_detail(request,username,article_id):
        user = UserInfo.objects.filter(username=username).first()      # 查当前站点的用户对象
        blog = user.blog
        article_obj=Article.objects.filter(pk=article_id).first()
        comment_list=Comment.objects.filter(article_id=article_id)
        return render(request,"article_detail.html",locals())

![评论.png][.png]

3、评论树：

article\_detail.html页面添加评论树代码：

<div class="comment_tree">
            <p>评论树</p>
        </div>
        <script>
            // 获取评论信息，以评论树形式展示
            $.ajax({
                url: "/blog/comment_tree/" + $(".info").attr("article_id"),
                success: function (comment_list) {
                    console.log(comment_list);
                    html = "";
                    $.each(comment_list, function (index, comment_dict) {
                        var comment_pk=comment_dict["pk"]
                        var comment_content=comment_dict["content"]
                        temp= '<div comment_tree_id='+comment_pk+' class="conmment_item"> <span class="content">'+comment_content+'</span></div>'
                        if (!comment_dict.parent_comment_id) {                           // 没有父评论，即根评论
                             $(".comment_tree").append(temp)}
                        else {                                                                                   // 子评论处理
                            var pid=comment_dict.parent_comment_id;
                            $("[comment_tree_id="+pid+"]").append(temp)
                        }
                    });
                }
            });
        </script>

views.py文件增加评论树视图函数：

def comment_tree(request,article_id):
        comment_list=list(Comment.objects.filter(article_id=article_id).values("content","pk","parent_comment_id"))
        print(comment_list)
        return JsonResponse(comment_list,safe=False)                #JsonResponse返回的是列表，需要参数safe=False处理

转载于:https://blog.51cto.com/qidian510/2122072

[.png]: https://s1.51cto.com/images/20180530/1527668016928643.png?x-oss-process=image/watermark,size_16,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_90,type_ZmFuZ3poZW5naGVpdGk=