嵌套评论 · laravel5

[TOC] # 准备工作 1.设计三张表users,posts,comments，表结构如下:# users ~~~ Schema::create('users', function (Blueprint $table) { $table->increments('id'); $table->string('name'); $table->string('email')->unique(); $table->string('password'); $table->rememberToken(); $table->timestamps(); }); ~~~ posts ~~~ Schema::create('posts', function (Blueprint $table) { $table->increments('id'); $table->string('title'); $table->integer('user_id')->index(); $table->text('content'); $table->timestamps(); }); ~~~ comments 其中parent_id主要表示该评论所属评论的id,如果不属于任何评论则为null ~~~ Schema::create('comments', function (Blueprint $table) { $table->increments('id'); $table->integer('user_id')->index(); $table->integer('post_id')->index(); $table->integer('parent_id')->index()->nullable(); $table->text('body'); $table->timestamps(); }); ~~~ # 表之间的关系如下 Post.php文件 ~~~ /** * 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 ~~~ /** * 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'); } ~~~ # 逻辑编写我们所要实现的嵌套评论其实在我们准备工作中已经有点思路了，我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，进行显示所有的评论，但是我们的评论里面涉及到一个字段就是parent_id，这个字段其实非常的特殊，我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')`,具体的过程如下: web.php文件 `\Auth::loginUsingId(1); //用户id为1的登录` //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) { $post->comments()->create([ 'body' => request('body'), 'user_id' => \Auth::id(), 'parent_id' => request('parent_id', null), ]); return back(); }); ~~~ # 视图代码视图方面我们需要实现嵌套，那么随着用户互相评论的越来越多的话，那么嵌套的层级也就越多，所以说，我们这里需要使用各小技巧来显示整个评论，我们使用@include()函数来显示，那么我们试图的结构如下: comments comments.blade.php form.blade.php list.blade.php posts show.blade.php 代码如下: show.blade.phpa ~~~ <!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link href="//cdn.bootcss.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <div class="container" style="margin-top: 100px"> <div class="col-md-10 col-md-offset-1"> <h2>{{$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 ~~~