Laravel Eloquent Edit Form with Associated Checkboxes Checked

gistfile1.txt

/*
* The issue at hand is how to show checked boxes in 
* a Laravel edit form using Eloquent models.
*/

/*
* My Models
*
*/

// models/Product.php

class Product extends Eloquent{
...
    public function categories(){
        return $this->belongsToMany('Category');
    }
...
}

// models/Category.php

class Category extends Eloquent{
...
    public function products(){
        return $this->belongsToMany('Product');
    }
...
}

/*
* My controller for Product class
*
*/

// controllers/ProductAdminController.php
class ProductAdminController extends BaseController{
        protected $product;

        protected $rules;

        protected $category;

        /**
         * Construct the object from model
         *
         */

        public function __construct(Product $product, Category $category)
        {
                $this->product = $product;

                $this->category = $category;
        }
        ...
        public function edit($id)
        {
                // Pass the Product with the given id and Categor[ies] with an eagr-load of associated Products

                return View::make('admin.products.edit')->with('product',$this->product->find($id))->with('categories',$this->category->with('products')->get());
        }
        ...
}

/*
* Blade Edit View
*
*/

// views/admin/products/edit.blade.php

{{ Form::model($product,array('route' => array('admin.products.update',$product->id),'method' => 'put')) }}

...

<fieldset>
<legend>Categories</legend>
<ul>

// loop through my categories which are eager-loaded with an array of associated products

@foreach($categories as $cat)

// if this category contains an instance of the product we're editing set the checkbox to true

    @if($cat->products->contains($product))
      <li>{{ Form::checkbox('categories[]',$cat->id,true,array('id'=>"category_$cat->id")) }}{{ Form::label("category_$cat->id",$cat->title) }}</li>

// otherwise the checkbox value is null

    @else
      <li>{{ Form::checkbox('categories[]',$cat->id,null,array('id'=>"category_$cat->id")) }}{{ Form::label("category_$cat->id",$cat->title) }}</li>

  @endif
@endforeach
</ul>
</fieldset>

...
{{ Form::close() }}