经常我们看见评论显示形式有很多，比如'@'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常见的就是嵌套式评论，因为这个更加醒目.
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
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
/** * 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) { $post->comments()->create([ 'body' => request('body'), 'user_id' => \Auth::id(), 'parent_id' => request('parent_id', null), ]); return back();});视图代码
视图方面我们需要实现嵌套，那么随着用户互相评论的越来越多的话，那么嵌套的层级也就越多，所以说，我们这里需要使用各小技巧来显示整个评论，我们使用@include()函数来显示，那么我们试图的结构如下:
- commentscomments.blade.phpform.blade.phplist.blade.php - postsshow.blade.php
代码如下:
show.blade.php
<!DOCTYPE html><html><head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link href="https://zhishitu.com/ke" rel="stylesheet"></head><body><div style="margin-top: 100px"> <div class="col-md-10 col-md-offset-1"> <h2>{{$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最终效果图如下
以上就是Laravel5实现嵌套评论的形式（代码详解）的知识。速戳>>知识兔学习精品课！