Once Laravel Package

Getting Started

Start by installing the package via Composer: composer require spatie/once. The core API is simplicity itself: wrap any expensive operation in Once::cache() with a unique ID and a closure. For example:

$result = Once::cache('expensive_lookup', fn() => expensiveComputation());

The first call executes the closure; subsequent calls with the same ID return the cached result. In Laravel, this works out-of-the-box in service providers, model accessors, or middleware—no configuration required. Begin by identifying repeated expensive calls (e.g., config parsing, API lookups) and memoizing them.

Implementation Patterns

• Method Memoization in Models: Cache derived attributes in accessors to avoid recomputing on every property access:

public function getCustomerScoreAttribute()
{
    return Once::cache('customer_score_'.$this->id, fn() => $this->calculateScore());
}

• Configuration Loading: Load and parse config files once per request:

$config = Once::cache('app_config', fn() => json_decode(file_get_contents('config.json'), true));

• Service Provider Optimizations: Avoid repeated heavy setup in boot():

Once::cache('register_custom_extensions', fn() => $this->registerExtensions());

• Middleware & Job Contexts: Cache computed values across multiple job/requests where state persists (e.g., within a Laravel queue job), but remember cache is request-scoped, not global.

Gotchas and Tips

• Request-Scoped Only: Cache lives only within a single PHP request lifecycle. Don’t expect persistence across HTTP requests or CLI invocations—this is not a Redis/DB cache. Reset occurs on Once::flush() or script termination.
• ID Uniqueness Matters: IDs must be globally unique per use case. Avoid dynamic IDs like md5($data) unless the data is stable and consistent across calls. Prefix IDs (e.g., 'user_' . $userId) to avoid collisions.
• Stateful Closures Can Break It: Never close over mutable variables that change between calls—Once caches the result, not recomputes if dependencies change. Prefer pure functions or ensure closure inputs are stable.
• Testing Tip: Use Once::flush() in your test fixtures (e.g., setUp() or between data provider rows) to reset state and avoid false positives.
• Laravel Tip: Works seamlessly with Laravel’s service container. Memoize expensive bindings in AppServiceProvider::register(), but avoid caching resolved instances that depend on transient state (e.g., Request).
• Performance Edge Case: For trivially fast operations (e.g., $a + $b), the overhead of Once::cache() may outweigh the benefit. Use it only for genuinely expensive ops (I/O, loops, recursions).