View Composers Keep Controllers Thin

The Problem

Your admin panel has a product filter form. Every controller method that renders this view needs to pass the same dropdown data:

// ProductController@index
public function index()
{
    $categories = Category::pluck('name', 'id');
    $brands = Brand::pluck('name', 'id');
    $statuses = ['active', 'draft', 'archived'];
    
    return view('products.index', compact('categories', 'brands', 'statuses'));
}

// ProductController@create
public function create()
{
    $categories = Category::pluck('name', 'id');
    $brands = Brand::pluck('name', 'id');
    $statuses = ['active', 'draft', 'archived'];
    
    return view('products.create', compact('categories', 'brands', 'statuses'));
}

// ProductController@edit
public function edit($id)
{
    $product = Product::findOrFail($id);
    $categories = Category::pluck('name', 'id');
    $brands = Brand::pluck('name', 'id');
    $statuses = ['active', 'draft', 'archived'];
    
    return view('products.edit', compact('product', 'categories', 'brands', 'statuses'));
}

Duplicated logic across multiple methods. When you add a new filter dropdown, you update 5+ methods.

The Fix

Use a view composer to bind data automatically:

// app/Providers/ViewServiceProvider.php
use Illuminate\Support\Facades\View;
use App\Models\Category;
use App\Models\Brand;

public function boot()
{
    View::composer('products.*', function ($view) {
        $view->with([
            'categories' => Category::pluck('name', 'id'),
            'brands' => Brand::pluck('name', 'id'),
            'statuses' => ['active', 'draft', 'archived'],
        ]);
    });
}

Now your controllers stay thin:

public function index()
{
    return view('products.index');
}

public function create()
{
    return view('products.create');
}

public function edit($id)
{
    $product = Product::findOrFail($id);
    return view('products.edit', compact('product'));
}

How It Works

The composer runs before every view that matches products.*. The data is automatically injected, so your Blade templates can access $categories, $brands, and $statuses without the controller passing them.

When to Use It

• Shared dropdown data across multiple views (categories, statuses, countries)
• Default filter values that every page needs
• Navigation menus or sidebars that appear on many pages
• Current user permissions for conditional UI elements

Trade-Offs

The data is fetched on every view render, even if the template doesn’t use it. If your composer queries are expensive, cache them or use class-based composers with dependency injection for better control.

But for simple dropdown data, view composers eliminate duplication and keep your controllers focused on actions, not view preparation.