Question

public function press (Request $request)
{
    if($request->has('search')){
        $articles =  Press::search($request->input('search'))->get();
    }
    return view('pages.press.index', compact('articles'));
}

我收到错误Undefined variable: articles。以上是我在我的控制器中使用的代码。我犯的错误是什么？

查看

 @if(!empty($articles))
    @foreach ($articles as $article)
      <div class="col-md-4">
        <div class="box border">
          <div class="box-header">
            <a href="{{ url('/press/'.$article->slug) }}"><img src="{{ url('http://assets.hobohweb.com/uploads/press/'.$article->image) }}" class="img-fluid" alt=""></a>
          </div>
          <div class="box-body">
            <a href="{{ url('/press/'.$article->slug) }}"><h6 class="h-2x">{{ $article->title }}</h6></a>
            {{ Carbon\Carbon::parse($article->created_at)->diffForHumans() }} on <a href="{{ url($article->source_url) }}" class="text-primary">{{ $article->source }}</a>
          </div>
        </div>
      </div>
    @endforeach
  @endif

Answer 1

您在if内声明变量，但如果条件为false，则永远不会设置变量。尝试使用else条件：

public function press (Request $request)
{
    if($request->has('search')){
        $articles =  Press::search($request->input('search'))->get();
    } else {
        $articles = null;
    }

    return view('pages.press.index', compact('articles'));
}

您还需要检查视图中$articles是否为空。

Answer 2

这是因为变量从未被赋值，并且在-if

的外部上下文中不存在

尝试使用此

public function press (Request $request)
{
  $articles = array();

   if($request->has('search')){
       $articles =  Press::search($request->input('search'))->get();
   }

   return view('pages.press.index', [
     'articles' => $articles
   ]);
}

查看

   @foreach ($articles as $article)
      <div class="col-md-4">
        <div class="box border">
         <div class="box-header">
           <a href="{{ url('/press/'.$article->slug) }}"><img src="{{ url('http://assets.hobohweb.com/uploads/press/'.$article->image) }}" class="img-fluid" alt=""></a>
         </div>
         <div class="box-body">
           <a href="{{ url('/press/'.$article->slug) }}"><h6 class="h-2x">{{ $article->title }}</h6></a>
           {{ Carbon\Carbon::parse($article->created_at)->diffForHumans() }} on <a href="{{ url($article->source_url) }}" class="text-primary">{{ $article->source }}</a>
         </div>
       </div>
     </div>
   @endforeach

我希望这可以帮到你

Answer 3

只需检查搜索中是否有文章，例如：

if($request->has('search')){
    $articles =  Press::search($request->input('search'))->get();
} else {
    $articles = [];
}

并在视图中使用它：

@forelse($articles as $article)
    ...
@empty
    <p>There are no articles!</p>
@endforelse

Laravel - 未定义的变量：文章

3 个答案: