Efficiently Cache Repeated Results In Laravel With The Once() Helper

🧠 Introduction

When building Laravel applications, it's common to run into scenarios where the same logic or query is executed multiple times in a single request. This can become inefficient, especially if the operation is heavy or touches the database.

Laravel provides a neat solution for this: the once() helper.

Let’s explore how it works and when you should use it.

🔍 What is once()?

The once() helper executes a given closure just once per request, caching the result. On subsequent calls (with the same closure), Laravel returns the previously computed value instead of re-running the logic.

once(Closure $callback): mixed

Think of it as a simple, request-bound memory cache — no Redis, files, or databases involved.

🧠 Why Use once() ?

• ✅ Avoid repeated expensive logic (e.g., database queries)
• ✅ Improve performance without needing full caching setup
• ✅ Keep your code clean and stateless
• ✅ Works great in service classes, Blade templates, or anywhere inside a request

💡 Real-World Use Case

Imagine you’re fetching user permissions that involve a complex database relationship:

$permissions = auth()->user()->permissions;

If you do this multiple times in a single request, you’ll hit the database repeatedly. Instead, use once():

$permissions = once(fn () => auth()->user()->permissions);

Now, no matter how many times you call that line during the request, the query runs just once.

🧪 Another Example

<?php
 
function appSettings(): array
{
    return once(function () {
        return \App\Models\Setting::pluck('value', 'key')->toArray();
    });
}
 
// You can now call appSettings() multiple times within the request
// without hitting the database again.

✅ When Should You Use once()?

• Complex or repeated DB queries
• API calls (within same request)
• Expensive computations
• Reading config or settings stored in the database

🚫 When Not to Use It

• If the data must change dynamically during the same request
• If you need to persist data between requests — use Laravel’s cache for that

🧵 Pro Tip

You can combine once() with helper functions to cache inline logic cleanly: helper.php

function currentWorkspace()
{
    return once(fn () => auth()->user()->workspaces()->first());
}

🛠 Alternative: Using userOnce Property in a Class

You can also cache results in a class property — like userOnce — which works similarly to once() but is scoped to the class instance:

class User extends Authenticatable
{
    protected $userOnce;
 
    public function authUser()
    {
        return $this->userOnce ??= auth()->user();
    }
}

This approach is useful when working within services or models where object-scoped caching is appropriate.

📚 Conclusion

The once() helper may look small, but it solves a real performance bottleneck in many Laravel apps — without needing complex caching strategies.

Next time you find yourself calling the same method repeatedly in a single request, wrap it in once() and enjoy faster, cleaner code.