Laravel View Models

 

The Laravel View Models by Brent Roose of Spatie is a package that can move the work you might do in a controller to a “view model”:

Have you ever made a controller where you had to do a lot of work to prepare variables to be passed to a view? You can move that kind of work to a so-called view model. In essence, view models are simple classes that take some data and transform it into something usable for the view.

A view model class is designed to house the complex logic of your views and clean up view-related logic from controllers:

class PostViewModel extends ViewModel
{
    public $indexUrl = null;

    public function __construct(User $user, Post $post = null)
    {
        $this->user = $user;
        $this->post = $post;

        $this->indexUrl = action([PostsController::class, 'index']);
    }

    public function post(): Post
    {
        return $this->post ?? new Post();
    }

    public function categories(): Collection
    {
        return Category::canBeUsedBy($this->user)->get();
    }
}

The above view model class gets created in the controller:

class PostsController
{
    public function create()
    {
        $viewModel = new PostViewModel(
            current_user()
        );

        return view('blog.form', $viewModel);
    }

    public function edit(Post $post)
    {
        $viewModel = new PostViewModel(
            current_user(),
            $post
        );

        return view('blog.form', $viewModel);
    }
}

And together, the view model and the controller provide your view with the following abilities:

<input type="text" value="{{ $post->title }}" />
<input type="text" value="{{ $post->body }}" />

<select>
    @foreach ($categories as $category)
        <option value="{{ $category->id }}">{{ $category->name }}</option>
    @endforeach
</select>

<a href="{{ $indexUrl }}">Back</a>

All public methods and properties in a view model are automatically exposed to the view.

I think this package is an excellent abstraction of this logic, and instead of passing the view model to the view, you can return a view directly like this:

class PostsController
{
    public function update(Request $request, Post $post)
    {
        // …

        return (new PostViewModel($post))->view('post.form');
    }
}

And last but not least, you can expose functions which require extra parameters:

class PostViewModel extends ViewModel
{
    public function formatDate(Carbon $date): string
    {
        return $date->format('Y-m-d');
    }
}

Which you can then reference in your template:

{{ $formatDate($post->created_at) }}

Thanks to Brent Roose and the folks at Spatie for this excellent package! You can access the code and installation instructions from the GitHub repository spatie/laravel-view-models.