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[Home](https://www.msaied.com) 2. / 3. [Articles](https://www.msaied.com/articles) 4. / 5. Eloquent Custom Casts: Encrypting, Compressing, and Composing Value Objects at the Model Layer Eloquent Custom Casts: Encrypting, Compressing, and Composing Value Objects at the Model Layer =============================================================================================== Go beyond built-in Eloquent casts. Learn to build custom CastsAttributes implementations that encrypt, compress, and hydrate rich value objects — keeping your models clean and your domain logic portable. ![](https://cdn.msaied.com/01M22N44A70A5MC2S599JP0MPH.webp) [Mohamed Said](https://www.msaied.com#person) Published 19 Oct 2026 · Updated 19 Oct 2026 · 3 min read ShareCopy linkCopied ![Eloquent Custom Casts: Encrypting, Compressing, and Composing Value Objects at the Model Layer](https://cdn.msaied.com/796/13df3306c87eeeccf69b380e7a07d8da.png) On this page +1. [Why Custom Casts Deserve More Attention](#why-custom-casts-deserve-more-attention) 2. [The Contract](#the-contract) 3. [Parameterised Casts](#parameterised-casts) 4. [Combining Encryption and Compression](#combining-encryption-and-compression) 5. [Inbound-Only Casts](#inbound-only-casts) 6. [Composing Casts with withCastParameters](#composing-casts-with-codewithcastparameterscode) 7. [Takeaways](#takeaways) Why Custom Casts Deserve More Attention --------------------------------------- Laravel ships with a solid set of built-in casts — `integer`, `encrypted`, `AsCollection`, `AsEnumCollection` — but the moment your domain needs a `Money`, `Temperature`, or `GeoPoint` value object, you're back to mutators and boilerplate. The `CastsAttributes` contract is the clean answer, and it composes better than you might expect. --- The Contract ------------ ```php use Illuminate\Contracts\Database\Eloquent\CastsAttributes; use Illuminate\Database\Eloquent\Model; /** * @implements CastsAttributes */ class MoneyCast implements CastsAttributes { public function get(Model $model, string $key, mixed $value, array $attributes): Money { $decoded = json_decode($value, true, flags: JSON_THROW_ON_ERROR); return new Money($decoded['amount'], Currency::from($decoded['currency'])); } public function set(Model $model, string $key, mixed $value, array $attributes): string { if (! $value instanceof Money) { throw new \InvalidArgumentException('Expected a Money instance.'); } return json_encode(['amount' => $value->amount, 'currency' => $value->currency->value], JSON_THROW_ON_ERROR); } } ``` Attach it on the model: ```php protected function casts(): array { return [ 'price' => MoneyCast::class, ]; } ``` Now `$order->price` is always a `Money` object. No mutator, no accessor, no leaking raw integers into view logic. --- Parameterised Casts ------------------- Casts accept constructor arguments via the colon syntax. Use this to make a single cast reusable across different precision requirements: ```php class RoundedDecimalCast implements CastsAttributes { public function __construct(private readonly int $scale = 2) {} public function get(Model $model, string $key, mixed $value, array $attributes): string { return number_format((float) $value, $this->scale, '.', ''); } public function set(Model $model, string $key, mixed $value, array $attributes): string { return bcscale($this->scale) ? bcdiv((string) $value, '1', $this->scale) : (string) $value; } } ``` ```php 'tax_rate' => RoundedDecimalCast::class . ':4', 'discount' => RoundedDecimalCast::class . ':2', ``` --- Combining Encryption and Compression ------------------------------------ Storing large JSON blobs encrypted is expensive. Compress first, then encrypt: ```php class CompressedEncryptedCast implements CastsAttributes { public function get(Model $model, string $key, mixed $value, array $attributes): mixed { if ($value === null) return null; $decrypted = decrypt($value); $decompressed = gzinflate(base64_decode($decrypted)); return json_decode($decompressed, true, flags: JSON_THROW_ON_ERROR); } public function set(Model $model, string $key, mixed $value, array $attributes): ?string { if ($value === null) return null; $json = json_encode($value, JSON_THROW_ON_ERROR); $compressed = base64_encode(gzdeflate($json, 9)); return encrypt($compressed); } } ``` This pattern is useful for audit payloads, GDPR-sensitive metadata, or any column where you need both confidentiality and storage efficiency without a separate pipeline step. --- Inbound-Only Casts ------------------ Implement `CastsInboundAttributes` when you only need to transform on write — for example, hashing a token before storage: ```php use Illuminate\Contracts\Database\Eloquent\CastsInboundAttributes; class Sha256Cast implements CastsInboundAttributes { public function set(Model $model, string $key, mixed $value, array $attributes): string { return hash('sha256', $value); } } ``` Reading returns the raw hash from the database, which is exactly what you want for comparison operations. --- Composing Casts with `withCastParameters` ----------------------------------------- For complex value objects that need injected services (e.g., a currency converter), avoid reaching into the container inside the cast. Instead, pass configuration through parameters and keep the cast stateless. If you genuinely need a service, register a custom cast class in the container and bind it via `Model::resolveRelationUsing` — but that's a code smell worth questioning first. --- Takeaways --------- - Implement `CastsAttributes` to hydrate domain value objects directly on Eloquent models. - Use constructor parameters (colon syntax) to make a single cast class reusable with different configurations. - Combine `gzdeflate` + `encrypt` in one cast to handle large sensitive blobs without a separate pipeline. - `CastsInboundAttributes` is the right tool when the read path should return raw database values. - Keep casts stateless; if you need a service, reconsider whether the cast is the right boundary. - [laravel](https://www.msaied.com/articles?search=laravel) - [eloquent](https://www.msaied.com/articles?search=eloquent) - [casts](https://www.msaied.com/articles?search=casts) - [value-objects](https://www.msaied.com/articles?search=value-objects) - [domain-driven-design](https://www.msaied.com/articles?search=domain-driven-design) Frequently asked questions --------------------------- Can a custom cast return null safely without throwing?Yes. Guard against null in both `get` and `set` by returning null early. Laravel passes null through to your cast when the column value is NULL, so explicit null checks are your responsibility. Does using a custom cast affect Eloquent dirty-checking?It can. Eloquent compares the serialised (set) representation for dirty detection. If your cast produces a non-deterministic string (e.g., unordered JSON keys), the model may appear dirty on every save. Use `JSON\_FORCE\_OBJECT` or sort keys before encoding to keep comparisons stable. How do I unit-test a custom cast in isolation?Instantiate the cast class directly and call `get` or `set` with a plain `new class extends Model {}` stub. You don't need a database connection to test cast logic, which makes these fast pure-unit tests. ![Mohamed Said](https://cdn.msaied.com/01M22N44A70A5MC2S599JP0MPH.webp)About the author ---------------- [Mohamed Said](https://www.msaied.com#person)Senior Backend Engineer specializing in Laravel, scalable SaaS platforms, APIs, and cloud infrastructure. I build secure, high-performance web applications that help businesses grow. [About](https://www.msaied.com#about) [GitHub ↗](https://github.com/EG-Mohamed) [LinkedIn ↗](https://www.linkedin.com/in/msaiedm/) [WhatsApp ↗](https://wa.me/201094619204) [Email Address ↗](mailto:hello@msaied.com) [My CV ↗](https://drive.google.com/file/u/0/d/1MF20IPRJyzfy32mhEutjL5EpSls0w2Q8/view) [Previous articleEloquent Query Optimization: Defeating N+1 Problems at the Source](https://www.msaied.com/articles/eloquent-query-optimization-defeating-n1-problems-at-the-source) On this page ------------- 1. [Why Custom Casts Deserve More Attention](#why-custom-casts-deserve-more-attention) 2. [The Contract](#the-contract) 3. [Parameterised Casts](#parameterised-casts) 4. [Combining Encryption and Compression](#combining-encryption-and-compression) 5. [Inbound-Only Casts](#inbound-only-casts) 6. [Composing Casts with withCastParameters](#composing-casts-with-codewithcastparameterscode) 7. [Takeaways](#takeaways) ### Have a technical challenge? Tell me what you’re building. I reply within two working days. 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