When To Use Laravel When

In Laravel, the when method is a versatile and elegant way to conditionally execute logic within your code. It simplifies conditional operations, improving readability and reducing clutter, particularly in chained methods or query builders.

Here’s a breakdown of when to use when in Laravel:

1. Conditional Query Building

The when method is often used to add conditions to query builders dynamically based on certain criteria.

Example: Applying a Filter Dynamically

$query = User::query();
$users = $query->when(request('role'), function ($q, $role) {
    $q->where('role', $role);
 })->get();        

? Why Use when Here?

? If request('role') exists, the condition is applied.

? If request('role') is null, the condition is skipped, keeping the code clean and concise.

2. Conditional Logic in Collections

The when method can also be used in collections to perform operations based on certain conditions.

Example: Transforming Data Conditionally

$collection = collect([1, 2, 3, 4]);
$result = $collection->when(true, function ($coll) {
    return $coll->map(fn ($item) => $item * 2);
});        

? Why Use when Here?

? It allows conditional execution without needing separate if statements, making the code more readable.

3. Cleaner Code in Controllers

The when method can simplify controller logic by removing multiple nested if statements.

Example: Conditionally Adding Features

$data = [];

$data = collect($data)->when($user->isAdmin(), function ($data) {
    return $data->put('admin_tools', true);
 })->when($user->isPremium(), function ($data) {
    return $data->put('premium_features', true);
});        

? Why Use when Here?

? Avoids deeply nested conditions.

? Keeps the logic declarative and easier to follow.

4. Improving Readability in Fluent Chains

When working with methods that are chained together, when can help conditionally apply parts of the chain without breaking the flow.

Example: Fluent Chain with Conditional Middleware

Route::get('/dashboard', [DashboardController::class, 'index'])->when(auth()->user()->isAdmin(), fn ($route) => $route->middleware('admin'));        

? Why Use when Here?

? Maintains a fluent interface while conditionally applying middleware.

5. In Custom Logic or Helper Functions

You can use when to conditionally execute logic in helper functions, avoiding explicit if statements.

Example: Simplifying a Helper Function

function formatPrice($price, $applyDiscount = false) {
     return collect(['price' => $price])
     ->when($applyDiscount, function ($data) {
          $data['price'] *= 0.9; // Apply 10% discount
     })->get('price');
}        

? Why Use when Here?

? Keeps the function logic compact and readable.

Conclusion

Use Laravel’s when method whenever you need to conditionally execute logic without breaking the flow of your code. It is particularly useful in:

? Query builders.

? Collections.

? Fluent chains.

? Replacing nested if statements for better readability.

By leveraging when, you can write cleaner, more expressive Laravel applications that are easier to maintain.