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What is the Conditionable trait?

Illuminate\Support\Traits\Conditionable adds when() and unless() to any class that uses it. These methods let you branch logic conditionally while keeping a fluent method chain intact.
The source lives in src/Illuminate/Conditionable/Traits/Conditionable.php. The Illuminate\Support\Traits\Conditionable namespace is an alias that points there.
Many Laravel classes use this trait: QueryBuilder, Eloquent Builder, Mail, Notification, and others.

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Basic usage

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when() — execute when the condition is truthy

use Illuminate\Support\Collection;

$results = collect([1, 2, 3, 4, 5])
    ->when(true, function (Collection $collection) {
        return $collection->filter(fn ($n) => $n > 2);
    });
// [3, 4, 5]
When the first argument is truthy the second argument (callback) runs. When it is falsy the optional third argument (default callback) runs instead. 
$results = collect([1, 2, 3, 4, 5])
    ->when(false, function (Collection $collection) {
        return $collection->filter(fn ($n) => $n > 2);
    }, function (Collection $collection) {
        return $collection->filter(fn ($n) => $n < 3);
    });
// [1, 2]

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unless() — execute when the condition is falsy

unless() is the inverse of when(). The callback runs when the condition is falsy. 
$results = collect([1, 2, 3, 4, 5])
    ->unless(false, function (Collection $collection) {
        return $collection->take(3);
    });
// [1, 2, 3]

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Why the chain continues

When the callback returns null, when() returns $this so the chain continues. When the callback returns a value, that value becomes the next item in the chain. 
// The chain continues because the callbacks return void/null
$query = User::query()
    ->when($request->has('active'), function ($query) {
        $query->where('active', true);
    })
    ->when($request->filled('name'), function ($query) use ($request) {
        $query->where('name', 'like', "%{$request->name}%");
    })
    ->orderBy('created_at', 'desc');
The source implementation is: 
if ($value) {
    return $callback($this, $value) ?? $this;
} elseif ($default) {
    return $default($this, $value) ?? $this;
}

return $this;
When the callback returns an explicit value, that value flows to the next call in the chain. When the callback returns nothing (null), $this is returned instead.

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Calling when() with no arguments — HigherOrderWhenProxy

Calling when() with zero arguments returns a HigherOrderWhenProxy. This lets you set the condition lazily. 
$query = User::query()
    ->when()->isActive()
    ->where('role', 'admin');
Calling when() with one argument returns a proxy that holds that value as the condition. 
// One argument: get a proxy with the condition already set
$proxy = collect([1, 2, 3])->when($request->has('filter'));
// $proxy->methodName() calls methodName() only when the condition is truthy

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Passing a closure as the condition

When the first argument is a closure, the closure’s return value is used as the condition. 
$results = User::query()
    ->when(
        fn ($query) => $request->filled('role'),
        fn ($query) => $query->where('role', $request->role)
    )
    ->get();
This lets you encapsulate the condition evaluation inside a callback.

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The classic QueryBuilder pattern

Dynamic query building with when() is the most common use case. 
public function index(Request $request)
{
    $users = User::query()
        ->when($request->filled('search'), function ($query) use ($request) {
            $query->where('name', 'like', "%{$request->search}%")
                  ->orWhere('email', 'like', "%{$request->search}%");
        })
        ->when($request->filled('role'), fn ($q) => $q->where('role', $request->role))
        ->when($request->boolean('verified'), fn ($q) => $q->whereNotNull('email_verified_at'))
        ->when(
            $request->filled('sort'),
            fn ($q) => $q->orderBy($request->sort, $request->get('direction', 'asc')),
            fn ($q) => $q->latest()
        )
        ->paginate();

    return UserResource::collection($users);
}

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Adding Conditionable to your own classes

Use the trait in any class to get when() and unless() for free. 
namespace App\Services;

use Illuminate\Support\Traits\Conditionable;

class ReportBuilder
{
    use Conditionable;

    protected array $filters = [];
    protected bool $includeArchived = false;
    protected ?string $groupBy = null;

    public function withArchived(): static
    {
        $this->includeArchived = true;

        return $this;
    }

    public function groupBy(string $column): static
    {
        $this->groupBy = $column;

        return $this;
    }

    public function addFilter(string $column, mixed $value): static
    {
        $this->filters[$column] = $value;

        return $this;
    }

    public function build(): \Illuminate\Database\Eloquent\Builder
    {
        return Report::query()
            ->when($this->includeArchived, fn ($q) => $q->withTrashed())
            ->when($this->groupBy, fn ($q) => $q->groupBy($this->groupBy))
            ->when($this->filters, function ($q) {
                foreach ($this->filters as $column => $value) {
                    $q->where($column, $value);
                }
            });
    }
}

// Usage
$query = (new ReportBuilder)
    ->when($request->boolean('archived'), fn ($b) => $b->withArchived())
    ->when($request->filled('group'), fn ($b) => $b->groupBy($request->group))
    ->addFilter('status', 'published')
    ->build();

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Using when() with Mail and Notifications

when() is available in Mailable and Notification classes too. 
use Illuminate\Mail\Mailable;

class OrderConfirmation extends Mailable
{
    public function build(): static
    {
        return $this
            ->subject('Your order has been received')
            ->view('emails.order.confirmation')
            ->when($this->order->hasDiscount(), function (Mailable $mail) {
                $mail->attach(storage_path('discounts/coupon.pdf'));
            })
            ->when(app()->environment('production'), function (Mailable $mail) {
                $mail->bcc('[email protected]');
            });
    }
}

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when() vs tap()

Both look similar but serve different purposes.
tap()when()
PurposeSide effects (logging, debugging)Conditional branching
Return valueAlways $this$this or the callback’s return value
ConditionNoneYes
// tap: use for side effects; always returns $this
$user = User::find($id)
    ->tap(fn ($user) => Log::info("User {$user->id} loaded"));

// when: use for conditional branching
$user = User::query()
    ->when($isAdmin, fn ($q) => $q->where('role', 'admin'))
    ->first();
If you only want to trigger a side effect (logging, debugging) mid-chain, use tap(). Use when() or unless() when you need to change behavior based on a condition.

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Next steps

Higher order messages

Learn how the $collection->map->method() syntax works and how to use it in practice.
Last modified on March 28, 2026