Laravel-5.7:所有类别都没有显示在db的标头中

Question

我试图得到所有的主要类别在标题的网站，但只有一个类别显示，谁能提供这个解决方案？

以下是ProductsController：

ProductsController.php

public function products($url = null)
{

  $categories = Category::with('products')->where(['parent_id'=>0])->get();
  $categoryDetails = Category::where(['url' => $url])->first();

  if($categoryDetails->parent_id==0)
  {
      //if url is main category url
      $subCategories = Category::where(['parent_id'=>$categoryDetails])->get();
      $cat_ids = "";
      foreach ($subCategories as $subCat) {
          $cat_ids .= $subCat->id.",";
      }
      $productsAll = Product::whereIn('category_id',array($cat_ids))->get();
  }
  else
  {
      //if url is sub category url
      $productsAll = Product::where(['category_id' => $categoryDetails->id])
                          ->get();
  }

  return view('products.listing')
            ->with(compact('categories','categoryDetails','productsAll'));
}

在listing.blade.php上，我写了这篇文章，将它与类别联系起来：

{{ $categoryDetails->name }}

主计长守则：

Controller.php

<?php

  namespace App\Http\Controllers;

  use Illuminate\Foundation\Bus\DispatchesJobs;
  use Illuminate\Routing\Controller as BaseController;
  use Illuminate\Foundation\Validation\ValidatesRequests;
  use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
  use App\Category;

  class Controller extends BaseController
  {
   use AuthorizesRequests, DispatchesJobs, ValidatesRequests;

    public static function mainCategories(){
    $mainCategories = Category::where(['parent_id' => 0])->get();
    $mainCategories = json_decode(json_encode($mainCategories));
    /*echo "<pre>"; print_r($mainCategories); die;*/
    return $mainCategories;
    }
   }

我在header视图中编写的代码：

header.blade.php

<?php use App\Http\Controllers\Controller;
  $mainCategories =  Controller::mainCategories();
?>

<!--some html-->

@foreach($mainCategories as $cat)
          <div class="dropdown-content">
               <a href="{{ asset('products/'.$cat->url) }}" style="margin-bottom: -10px;">{{ $cat->name }}</a>
          </div>
@endforeach

Answer 1

试着改变

<?php use App\Http\Controllers\Controller;
  $mainCategories =  Controller::mainCategories();
?>

至

<?php 
  use App\Controller;
  $mainCategories =  Controller::mainCategories();
?>

或更直接地：

<?php 
   $mainCategories =  App\Controller::mainCategories();
?>

在header.blade.php中

Answer 2

您可以为此使用视图数据(https://laravel.com/docs/master/views#passing-data-to-views)：

在您的App/Providers/AppServiceProvider.php文件中：

public function boot()
{
    View::share('mainCategories', Category::where(['parent_id' => 0])->get());
}

只需使用：

@foreach($mainCategories as $cat)
  // .... your code
@endforeach

在模板文件中。