Why is my form not submitting to the pivot table?

Question

I am using Laravel 5. I am following this tutorial on using a form to create tagged articles. I replaced the tags with categories. My articles belong to many categories, and my categories belong to many articles. I have a form for creating a new article, but it only creates an entry in the table articles, not in the pivot table article_category.

I get this error:

FatalErrorException in ArticlesController.php line 77:

Calling member functions () in an array

I think the problem is with the fourth line in the function store. I can not find anyone with the same problem. This line should attach the article idto the category ids, but it does not work. Grateful for any help.

My articles Controller:

public function store(CreateArticleRequest $request)
{

     $article = $request->all();

    Article::create($article);

    $categoriesId = $request->input('categories');

    $article->categories()->attach($categoriesId);

    return redirect()->route('articles_path');

}

Namespaces:

namespace App\Http\Controllers;

use App\Article;
use Illuminate\Http\Request;
use App\Http\Requests;
use App\Http\Requests\CreateArticleRequest;
use App\Http\Controllers\Controller;
use App\Category;
use App\Day;

Routes

Route::resource('articles', 'ArticlesController', [

    'names' => [

        'index' => 'articles_path',
        'show' => 'article_path',
        'edit' => 'articleEdit_path',
        'update' => 'articleUpdate_path',
        'create' => 'articleCreate_path',
        'store' => 'articleStore_path'
    ]

    ]);

:

namespace App;
use Illuminate\Database\Eloquent\Model;
class Article extends Model
{
    public function categories()
    {
        return $this->belongsToMany('App\Category', 'article_category', 'category_id', 'article_id')->withTimestamps();
    }
protected $fillable = array('title', 'description', 'image', 'lat', 'lng');

}

namespace App;

use Illuminate\Database\Eloquent\Model;

class Category extends Model
{
    public function articles()
    {
        return $this->belongsToMany('App\Article', 'article_category', 'article_id', 'category_id')->withTimestamps();
    }

protected $fillable = array('name'); 
}

PivotTable:

Schema::create('article_category', function (Blueprint $table) {
    $table->integer('article_id')->unsigned()->index();
    $table->foreign('article_id')->references('id')->on('articles')->onDelete('cascade');
    $table->integer('category_id')->unsigned()->index();
    $table->foreign('category_id')->references('id')->on('categories')->onDelete('cascade');
    $table->timestamps();
});

Answer 1

:

$article = $request->all();

Article::create($article);

$article = Article::create($request->all());

public function categories()
{
    return $this->belongsToMany('App\Category', 'article_category', 'article_id', 'category_id')->withTimestamps();
}