Laravel 5~嵌套评论的实现

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();
        });

2.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

//显示文章和相应的评论
Route::get('/products/{product}', 'ProductsController@show')->name('products.show');
//用户进行评论
Route::post('/products/{product}/comments', 'CommentsController@store')->name('products.comments');

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

    comment.blade.php

    form.blade.php

    list.blade.php

posts

show.blade.php

代码如下:
show.blade.phpa

<!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="//cdn.bootcss.com/bootstrap/3.3.6/css/bootstrap.min.css" 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>
    <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>
        <label for="body">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

最后控制器逻辑:

CommentsController.php

<?php

namespace App\Http\Controllers;

use App\Models\Comment;
use App\Models\Product;
use Illuminate\Http\Request;

class CommentsController extends Controller
{
    /**
     * @param Product $product
     * @return \Illuminate\Http\JsonResponse
     */
    public function store(Product $product)
    {
        if (request('parent_id')) {
            $real_comment = Comment::findOrFail(request('parent_id'));
            $level = $real_comment->level + 1;
            if ($level >= 3) {
                $level = 3;
            }
        }
        $comment = $product->comments()->create([
            // 'body' => request('body'),
            // 'user_id' => \Auth::id(),
            // 'level' => $level ?? 0,
            // 'parent_id' => request('parent_id', null),
            'body' => request('body'),
            'user_id' => \Auth::id(),
            'parent_id' => request('parent_id', null),
        ]);
        $comment = Comment::with('owner')->find($comment->id);
        return response()->json([
            'success' => true,
            'reply_block' => $comment,
        ]);
    }
}

ProductsController.php

    public function show(Product $product,Request $request)
    {
     
        $product->load('comments.owner');
        $comments = $product->getComments();
        $comments['root'] = $comments[''];
        unset($comments['']);
     return view('products.show',[
     'product'=>$product,
            'comments'=>$comments,
     ]);
    }
阅读 42

Comments