Laravel 5~嵌套评论的实现

时间 2019-12-06

标签 laravel 嵌套评论实现繁體版

原文原文链接

常常咱们看见评论显示形式有不少，好比'@'某某，又或者像知乎的收缩式的评论，又或者是嵌套式的评论，那么最一开始也是最多见的就是嵌套式评论，由于这个更加醒目.php

准备工做
1.设计三张表users,posts,comments，表结构以下:css

usershtml

Schema::create('users', function (Blueprint $table) {
    $table->increments('id');
    $table->string('name');
    $table->string('email')->unique();
    $table->string('password');
    $table->rememberToken();
    $table->timestamps();
});

postsvue

Schema::create('posts', function (Blueprint $table) {
    $table->increments('id');
    $table->string('title');
    $table->integer('user_id')->index();
    $table->text('content');
    $table->timestamps();
});

commentslaravel

Schema::create('comments', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('user_id')->index();
    $table->integer('post_id')->index();
    $table->integer('parent_id')->index()->default(0);
    $table->text('body');
    $table->timestamps();
});

2.Model层:
Post.php文件web

/**
 * 一篇文章有多个评论
 * @return \Illuminate\Database\Eloquent\Relations\HasMany
 */
public function comments()
{
    return $this->hasMany(Comment::class);
}

/**
 * 获取这篇文章的评论以parent_id来分组
 * @return static
 */
public function getComments()
{
    return $this->comments()->with('owner')->get()->groupBy('parent_id');
}

Comments.php文件bootstrap

/**
 * 这个评论的所属用户
 * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
 */
public function owner()
{
    return $this->belongsTo(User::class, 'user_id');
}

/**
 * 这个评论的子评论
 * @return \Illuminate\Database\Eloquent\Relations\HasMany
 */
public function replies()
{
    return $this->hasMany(Comment::class, 'parent_id');
}

逻辑编写
咱们所要实现的嵌套评论其实在咱们准备工做中已经有点思路了，咱们首先将一篇文章显示出来，同时利用文章与评论的一对多关系，进行显示全部的评论，可是咱们的评论里面涉及到一个字段就是parent_id，这个字段其实很是的特殊，咱们利用这个字段来进行分组, 代码就是上面的return $this->comments()->with('owner')->get()->groupBy('parent_id'),具体的过程以下:函数

web.php文件post

\Auth::loginUsingId(1); //用户id为1的登陆

//显示文章和相应的评论
Route::get('/post/show/{post}', function (\App\Post $post) {
    $post->load('comments.owner');
    $comments = $post->getComments();
    $comments['root'] = $comments[''];
    unset($comments['']);
    return view('posts.show', compact('post', 'comments'));
});

//用户进行评论
Route::post('post/{post}/comments', function (\App\Post $post) {
    $post->comments()->create([
        'body' => request('body'),
        'user_id' => \Auth::id(),
        'parent_id' => request('parent_id', null),
    ]);
    return back();
});

视图代码
视图方面咱们须要实现嵌套，那么随着用户互相评论的愈来愈多的话，那么嵌套的层级也就越多，因此说，咱们这里须要使用各小技巧来显示整个评论，咱们使用@include()函数来显示，那么咱们试图的结构以下:ui

- comments
comments.blade.php
form.blade.php
list.blade.php

 - posts
show.blade.php

代码以下:
show.blade.php

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link href="//cdn.bootcss.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<div class="container" style="margin-top: 100px">
    <div class="col-md-10 col-md-offset-1">
        <h2>{{$post->title}}</h2>
        <h4>{{$post->content}}</h4>
        <hr>
        @include('comments.list',['collections'=>$comments['root']])
        <h3>留下您的评论</h3>
        @include('comments.form',['parentId'=>$post->id])
    </div>
</div>
</body>
</html>

comment.blade.php

<div class="col-md-12">
    <h5><span style="color:#31b0d5">{{$comment->owner->name}}</span>:</h5>
    <h5>{{$comment->body}}</h5>

    @include('comments.form',['parentId'=>$comment->id])

    @if(isset($comments[$comment->id]))
        @include('comments.list',['collections'=>$comments[$comment->id]])
    @endif
    <hr>
</div>

form.blade.php

<form method="POST" action="{{url('post/'.$post->id.'/comments')}}" accept-charset="UTF-8">
    {{csrf_field()}}

    @if(isset($parentId))
        <input type="hidden" name="parent_id" value="{{$parentId}}">
    @endif

    <div class="form-group">
        <label for="body" class="control-label">Info:</label>
        <textarea id="body" name="body"  class="form-control" required="required"></textarea>
    </div>
    <button type="submit" class="btn btn-success">回复</button>
</form>

list.blade.php

@foreach($collections as $comment)
    @include('comments.comment',['comment'=>$comment])
@endforeach

最终效果图以下

最近在研究laravel,看到一个以前作过的功能，以前写的比较繁琐，特记录下来。
摘自：
https://laravel-china.org/art...
https://laravel-china.org/art...