多层评测系统

Question

我对刀片递归部分视图有困难。除了comment.blade.php文件中的递归之外，一切都可以正常工作。

我知道我需要在@include('articles.comments.comment', $comment)周围使用一个程序来再次调用自己，但我不知道如何调用它。

article_comments表：

id
message
user_id
parent_id
created_at
updated_at

app\Article.php类：

class Article extends Model {

    protected $table = 'articles';

    protected $fillable = [
        'category',
        'title',
        'permalink',
        'synopsis',
        'body',
        'source',
        'show_author',
        'published_at'
    ];

    protected $dates = ['published_at'];

    public function scopePublished($query)
    {
        $query->where('published_at', '<=', Carbon::now());
    }

    public function setPublishedAtAttribute($date)
    {
        $this->attributes['published_at'] = Carbon::parse($date);
    }

    public function comments()
    {
        return $this->hasMany('App\Comments')->where('parent_id', 0);
    }

}

app\Comments.php类：

class Comments extends Model {

    protected $table = 'article_comments';

    protected $fillable = [
        'parent_id',
        'message',
    ];

    public function author() {
        return $this->belongsTo('App\User'); 
    }

    public function children()
    {
        return $this->hasMany('App\Comments', 'parent_id');
    }

    public function countChildren($node = null)
    {
        $query = $this->children();
        if (!empty($node)) {
            $query = $query->where('node', $node);
        }

        $count = 0;
        foreach ($query->get() as $child) {
            // Plus 1 to count the direct child
            $count += $child->countChildren() + 1; 
        }
        return $count;
    }

}

app\Http\Controllers\ArticlesController.php

public function show($permalink)
{
    $article = Article::where('permalink', '=', $permalink)->with('comments','comments.author','comments.children')->first();
    if ($article != null) {
        $comments = $article->comments;
        return view('articles.show', compact('article','comments'));
    } else {
        return redirect('/')->with('error', 'This article does not exist.');
    }
}

resources\views\articles\show.blade.php

@if (count($comments) > 0)
    <ul>
    @foreach ($comments as $comment)
        @include('articles.comments.comment', ['comment'=>$comment])
    @endforeach
    </ul>
@else
    no comments
@endif

resources\views\articles\comments\comment.blade.php

<li>
    {{ $comment->message }}

    @if (count($comment->children) > 0)
        <ul>
        @foreach ($comment->children as $child)
            @include('articles.comments.comment', ['comment'=>$child])
        @endforeach
        </ul>
    @endif
</li>

电流错误：

Invalid argument supplied for foreach() (View: /var/www/dev.example.com/resources/views/articles/comments/comment.blade.php) (View: 

Answer 1

你们关系很好。我认为这应该是可行的：

resources\views\articles\show.blade.php

@if (count($comments) > 0)
    <ul>
        @each('articles.comments.comment', $comments, 'comment');
    </ul>
@else
    no comments
@endif

resources\views\articles\comments\comment.blade.php

<li>
    {{ $comment->message }}

    @if (count($comment->children) > 0)
        <ul>
            @each('articles.comments.comment', $comment->children, 'comment');
        </ul>
    @endif
</li>

app\Http\Controllers\ArticlesController.php:

$article = Article::where('permalink', '=', $permalink)->with('comments','comments.author','comments.children')->first();
$comments = $article->comments;
return view('articles.show', compact('article','comments'));

Answer 2

首先，我看到您将所有注释放置在一个页面中而不进行任何分页，但是，您将Article模型上的Article方法限制为只有具有parent_id=0的注释才能获得根注释。但是，再看看您的代码，在控制器中，您将缓慢地加载comments.author和comments.children。请注意，延迟加载只会发生在第一个父注释上，然后，所有子节点都必须执行大量查询才能获得它们之间的关系，方法是急切地加载这些关系。

如果您仍然希望将所有注释放在一个页面中，我建议您删除parent_id=0约束并一次性加载这些注释，并应用一种策略对它们进行排序。下面是一个例子：

app\Article.php

class Article extends Model {

    // ...

    public function comments()
    {
        return $this->hasMany('App\Comments');
    }

}

app\Http\Controllers\ArticlesController.php

use Illuminate\Database\Eloquent\Collection; 

// ...

public function show($permalink)
{
    $article = Article::where('permalink', '=', $permalink)->with('comments','comments.author','comments.children')->first();

    if ($article != null) {

        $comments = $this->buildCommentTree($article->comments);

        return view('articles.show', compact('article','comments'));
    } else {
        return redirect('/')->with('error', 'This article does not exist.');
    }
}


protected function buildCommentTree(Collection $comments, $root = 0)
{
    $branch = new Collection();

    $comments->each(function(Comment $comment) use ($root) {
        if ($comment->parent_id == $root) {

            $children = $this->buildCommentTree($comments, $comment->getKey());

            $branch->push($comment);
        } else {
            // This is to guarantee that children is always a Collection and to prevent Eloquent 
            // from hitting on the database looking for the children
            $children = new Collection();
        }

        $comment->setRelation('children', $children);
    });

    return $branch;

}

现在，我们已经对所有的评论进行了排序，而没有对数据库进行惩罚，我们可以开始遍历广告了。我更喜欢使用两个文件而不是一个进行循环，这样以后我就可以重用代码了。

resources\views\articles\show.blade.php

@if (!$comments->isEmpty())
    @include("articles.comments.container", ['comments'=>$comments])
@else
    no comments
@endif

resources\views\articles\comments\container.blade.php

@if (!$comments->isEmpty())
    <ul>
    @foreach ($comments as $comment)
        @include('articles.comments.show', ['comment'=>$comment])
    @endforeach
    </ul>
@else

resources\views\articles\comments\show.blade.php

<li>
    {{ $comment->message }}

    @if (!$comment->children->isEmpty())
        @include("articles.comments.container", ['comments'=>$comment->children])
    @endif
</li>

Answer 3

我可能漏掉了什么东西，但在我看来，你的代码太复杂了。例如，您可以在注释模型中添加一个user关系(也可以删除整个count方法)：

public function user()
{
    return $this->belongsTo('App\User');
}

然后，每当您需要访问注释的用户id或用户名时，只需调用：

$user_id = $comment->user->id;
$username = $comment->user->username;

那么，您应该能够清理大量的控制器：

$article = Article::where('permalink', '=', $permalink)->first();
$comments = Comments::where('article_id', '=', $article->id)->get();

您的show.blade.php文件应该是正常的。您的comment.blade.php文件可以这样编写：

<li>{{ $comment->message }}</li>
@if ($comment->children->count() > 0)
    <ul>
        @foreach($comment->children as $child)
            @include('articles.comments.comment', $child)
        @endforeach
    </ul>
@endif

我相信您对Invalid argument supplied for foreach()错误的问题与您对评论的原始查询有关。错误应该通过使用适当的关系模型来修正。

另外，如果您需要通过一个node列来计算您的评论的子级，您应该可以这样做：

$comment->children()->where('node', $node)->get()->count();