嵌套評論 · laravel5

[TOC] # 準備工作 1.設計三張表users,posts,comments，表結構如下:# 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主要表示該評論所屬評論的id,如果不屬于任何評論則為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(); }); ~~~ # 表之間的關系如下 Post.php文件 ~~~ /** * 一篇文章有多個評論 * @return \Illuminate\Database\Eloquent\Relations\HasMany */ public function comments() { return $this->hasMany(Comment::class); } /** * 獲取這篇文章的評論以parent_id來分組 * @return static */ public function getComments() { return $this->comments()->with('owner')->get()->groupBy('parent_id'); } ~~~ Comments.php文件 ~~~ /** * 這個評論的所屬用戶 * @return \Illuminate\Database\Eloquent\Relations\BelongsTo */ public function owner() { return $this->belongsTo(User::class, 'user_id'); } /** * 這個評論的子評論 * @return \Illuminate\Database\Eloquent\Relations\HasMany */ public function replies() { return $this->hasMany(Comment::class, 'parent_id'); } ~~~ # 邏輯編寫我們所要實現的嵌套評論其實在我們準備工作中已經有點思路了，我們首先將一篇文章顯示出來，同時利用文章與評論的一對多關系，進行顯示所有的評論，但是我們的評論里面涉及到一個字段就是parent_id，這個字段其實非常的特殊，我們利用這個字段來進行分組, 代碼就是上面的`return $this->comments()->with('owner')->get()->groupBy('parent_id')`,具體的過程如下: web.php文件 `\Auth::loginUsingId(1); //用戶id為1的登錄` //顯示文章和相應的評論 ~~~ 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')); }); ~~~ //用戶進行評論 ~~~ Route::post('post/{post}/comments', function (\App\Post $post) { $post->comments()->create([ 'body' => request('body'), 'user_id' => \Auth::id(), 'parent_id' => request('parent_id', null), ]); return back(); }); ~~~ # 視圖代碼視圖方面我們需要實現嵌套，那么隨著用戶互相評論的越來越多的話，那么嵌套的層級也就越多，所以說，我們這里需要使用各小技巧來顯示整個評論，我們使用@include()函數來顯示，那么我們試圖的結構如下: comments comments.blade.php form.blade.php list.blade.php posts show.blade.php 代碼如下: show.blade.phpa ~~~ <!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link href="//cdn.bootcss.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <div class="container" style="margin-top: 100px"> <div class="col-md-10 col-md-offset-1"> <h2>{{$post->title}}</h2> <h4>{{$post->content}}</h4> <hr> @include('comments.list',['collections'=>$comments['root']]) <h3>留下您的評論</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="{{$parentId}}"> @endif <div class="form-group"> <label for="body" class="control-label">Info:</label> <textarea id="body" name="body" class="form-control" required="required"></textarea> </div> <button type="submit" class="btn btn-success">回復</button> </form> ~~~ list.blade.php ~~~ @foreach($collections as $comment) @include('comments.comment',['comment'=>$comment]) @endforeach ~~~