Eloquent: Mutators & Casting
Introduction
Accessors, mutators, and attribute casting allow you to transform Eloquent attribute values when you retrieve or set them on model instances. For example, you may want to use the Laravel encrypter to encrypt a value while it is stored in the database, and then automatically decrypt the attribute when you access it on an Eloquent model. Or, you may want to convert a JSON string that is stored in your database to an array when it is accessed via your Eloquent model.
Accessors and Mutators
Defining an Accessor
An accessor transforms an Eloquent attribute value when it is accessed. To define an accessor, create a protected method on your model to represent the accessible attribute. This method name should correspond to the "camel case" representation of the true underlying model attribute / database column when applicable.
In this example, we'll define an accessor for the first_name
attribute. The accessor will automatically be called by Eloquent when attempting to retrieve the value of the first_name
attribute. All attribute accessor / mutator methods must declare a return type-hint of Illuminate\Database\Eloquent\Casts\Attribute
:
<?php namespace App\Models; use Illuminate\Database\Eloquent\Casts\Attribute;use Illuminate\Database\Eloquent\Model; class User extends Model{ /** * Get the user's first name. */ protected function firstName(): Attribute { return Attribute::make( get: fn (string $value) => ucfirst($value), ); }}
All accessor methods return an Attribute
instance which defines how the attribute will be accessed and, optionally, mutated. In this example, we are only defining how the attribute will be accessed. To do so, we supply the get
argument to the Attribute
class constructor.
As you can see, the original value of the column is passed to the accessor, allowing you to manipulate and return the value. To access the value of the accessor, you may simply access the first_name
attribute on a model instance:
use App\Models\User; $user = User::find(1); $firstName = $user->first_name;
If you would like these computed values to be added to the array / JSON representations of your model, you will need to append them.
Building Value Objects From Multiple Attributes
Sometimes your accessor may need to transform multiple model attributes into a single "value object". To do so, your get
closure may accept a second argument of $attributes
, which will be automatically supplied to the closure and will contain an array of all of the model's current attributes:
use App\Support\Address;use Illuminate\Database\Eloquent\Casts\Attribute; /** * Interact with the user's address. */protected function address(): Attribute{ return Attribute::make( get: fn (mixed $value, array $attributes) => new Address( $attributes['address_line_one'], $attributes['address_line_two'], ), );}
Accessor Caching
When returning value objects from accessors, any changes made to the value object will automatically be synced back to the model before the model is saved. This is possible because Eloquent retains instances returned by accessors so it can return the same instance each time the accessor is invoked:
use App\Models\User; $user = User::find(1); $user->address->lineOne = 'Updated Address Line 1 Value';$user->address->lineTwo = 'Updated Address Line 2 Value'; $user->save();
However, you may sometimes wish to enable caching for primitive values like strings and booleans, particularly if they are computationally intensive. To accomplish this, you may invoke the shouldCache
method when defining your accessor:
protected function hash(): Attribute{ return Attribute::make( get: fn (string $value) => bcrypt(gzuncompress($value)), )->shouldCache();}
If you would like to disable the object caching behavior of attributes, you may invoke the withoutObjectCaching
method when defining the attribute:
/** * Interact with the user's address. */protected function address(): Attribute{ return Attribute::make( get: fn (mixed $value, array $attributes) => new Address( $attributes['address_line_one'], $attributes['address_line_two'], ), )->withoutObjectCaching();}
Defining a Mutator
A mutator transforms an Eloquent attribute value when it is set. To define a mutator, you may provide the set
argument when defining your attribute. Let's define a mutator for the first_name
attribute. This mutator will be automatically called when we attempt to set the value of the first_name
attribute on the model:
<?php namespace App\Models; use Illuminate\Database\Eloquent\Casts\Attribute;use Illuminate\Database\Eloquent\Model; class User extends Model{ /** * Interact with the user's first name. */ protected function firstName(): Attribute { return Attribute::make( get: fn (string $value) => ucfirst($value), set: fn (string $value) => strtolower($value), ); }}
The mutator closure will receive the value that is being set on the attribute, allowing you to manipulate the value and return the manipulated value. To use our mutator, we only need to set the first_name
attribute on an Eloquent model:
use App\Models\User; $user = User::find(1); $user->first_name = 'Sally';
In this example, the set
callback will be called with the value Sally
. The mutator will then apply the strtolower
function to the name and set its resulting value in the model's internal $attributes
array.
Mutating Multiple Attributes
Sometimes your mutator may need to set multiple attributes on the underlying model. To do so, you may return an array from the set
closure. Each key in the array should correspond with an underlying attribute / database column associated with the model:
use App\Support\Address;use Illuminate\Database\Eloquent\Casts\Attribute; /** * Interact with the user's address. */protected function address(): Attribute{ return Attribute::make( get: fn (mixed $value, array $attributes) => new Address( $attributes['address_line_one'], $attributes['address_line_two'], ), set: fn (Address $value) => [ 'address_line_one' => $value->lineOne, 'address_line_two' => $value->lineTwo, ], );}
Attribute Casting
Attribute casting provides functionality similar to accessors and mutators without requiring you to define any additional methods on your model. Instead, your model's casts
method provides a convenient way of converting attributes to common data types.
The casts
method should return an array where the key is the name of the attribute being cast and the value is the type you wish to cast the column to. The supported cast types are:
-
array
-
AsStringable::class
-
boolean
-
collection
-
date
-
datetime
-
immutable_date
-
immutable_datetime
-
decimal:<precision>
-
double
-
encrypted
-
encrypted:array
-
encrypted:collection
-
encrypted:object
-
float
-
hashed
-
integer
-
object
-
real
-
string
-
timestamp
To demonstrate attribute casting, let's cast the is_admin
attribute, which is stored in our database as an integer (0
or 1
) to a boolean value:
<?php namespace App\Models; use Illuminate\Database\Eloquent\Model; class User extends Model{ /** * Get the attributes that should be cast. * * @return array<string, string> */ protected function casts(): array { return [ 'is_admin' => 'boolean', ]; }}
After defining the cast, the is_admin
attribute will always be cast to a boolean when you access it, even if the underlying value is stored in the database as an integer:
$user = App\Models\User::find(1); if ($user->is_admin) { // ...}
If you need to add a new, temporary cast at runtime, you may use the mergeCasts
method. These cast definitions will be added to any of the casts already defined on the model:
$user->mergeCasts([ 'is_admin' => 'integer', 'options' => 'object',]);
Attributes that are null
will not be cast. In addition, you should never define a cast (or an attribute) that has the same name as a relationship or assign a cast to the model's primary key.
Stringable Casting
You may use the Illuminate\Database\Eloquent\Casts\AsStringable
cast class to cast a model attribute to a fluent Illuminate\Support\Stringable
object:
<?php namespace App\Models; use Illuminate\Database\Eloquent\Casts\AsStringable;use Illuminate\Database\Eloquent\Model; class User extends Model{ /** * Get the attributes that should be cast. * * @return array<string, string> */ protected function casts(): array { return [ 'directory' => AsStringable::class, ]; }}
Array and JSON Casting
The array
cast is particularly useful when working with columns that are stored as serialized JSON. For example, if your database has a JSON
or TEXT
field type that contains serialized JSON, adding the array
cast to that attribute will automatically deserialize the attribute to a PHP array when you access it on your Eloquent model:
<?php namespace App\Models; use Illuminate\Database\Eloquent\Model; class User extends Model{ /** * Get the attributes that should be cast. * * @return array<string, string> */ protected function casts(): array { return [ 'options' => 'array', ]; }}
Once the cast is defined, you may access the options
attribute and it will automatically be deserialized from JSON into a PHP array. When you set the value of the options
attribute, the given array will automatically be serialized back into JSON for storage:
use App\Models\User; $user = User::find(1); $options = $user->options; $options['key'] = 'value'; $user->options = $options; $user->save();
To update a single field of a JSON attribute with a more terse syntax, you may make the attribute mass assignable and use the ->
operator when calling the update
method:
$user = User::find(1); $user->update(['options->key' => 'value']);
Array Object and Collection Casting
Although the standard array
cast is sufficient for many applications, it does have some disadvantages. Since the array
cast returns a primitive type, it is not possible to mutate an offset of the array directly. For example, the following code will trigger a PHP error:
$user = User::find(1); $user->options['key'] = $value;
To solve this, Laravel offers an AsArrayObject
cast that casts your JSON attribute to an ArrayObject class. This feature is implemented using Laravel's custom cast implementation, which allows Laravel to intelligently cache and transform the mutated object such that individual offsets may be modified without triggering a PHP error. To use the AsArrayObject
cast, simply assign it to an attribute:
use Illuminate\Database\Eloquent\Casts\AsArrayObject; /** * Get the attributes that should be cast. * * @return array<string, string> */protected function casts(): array{ return [ 'options' => AsArrayObject::class, ];}
Similarly, Laravel offers an AsCollection
cast that casts your JSON attribute to a Laravel Collection instance:
use Illuminate\Database\Eloquent\Casts\AsCollection; /** * Get the attributes that should be cast. * * @return array<string, string> */protected function casts(): array{ return [ 'options' => AsCollection::class, ];}
If you would like the AsCollection
cast to instantiate a custom collection class instead of Laravel's base collection class, you may provide the collection class name as a cast argument:
use App\Collections\OptionCollection;use Illuminate\Database\Eloquent\Casts\AsCollection; /** * Get the attributes that should be cast. * * @return array<string, string> */protected function casts(): array{ return [ 'options' => AsCollection::using(OptionCollection::class), ];}
Date Casting
By default, Eloquent will cast the created_at
and updated_at
columns to instances of Carbon, which extends the PHP DateTime
class and provides an assortment of helpful methods. You may cast additional date attributes by defining additional date casts within your model's casts
method. Typically, dates should be cast using the datetime
or immutable_datetime
cast types.
When defining a date
or datetime
cast, you may also specify the date's format. This format will be used when the model is serialized to an array or JSON:
/** * Get the attributes that should be cast. * * @return array<string, string> */protected function casts(): array{ return [ 'created_at' => 'datetime:Y-m-d', ];}
When a column is cast as a date, you may set the corresponding model attribute value to a UNIX timestamp, date string (Y-m-d
), date-time string, or a DateTime
/ Carbon
instance. The date's value will be correctly converted and stored in your database.
You may customize the default serialization format for all of your model's dates by defining a serializeDate
method on your model. This method does not affect how your dates are formatted for storage in the database:
/** * Prepare a date for array / JSON serialization. */protected function serializeDate(DateTimeInterface $date): string{ return $date->format('Y-m-d');}
To specify the format that should be used when actually storing a model's dates within your database, you should define a $dateFormat
property on your model:
/** * The storage format of the model's date columns. * * @var string */protected $dateFormat = 'U';
Date Casting, Serialization, and Timezones
By default, the date
and datetime
casts will serialize dates to a UTC ISO-8601 date string (YYYY-MM-DDTHH:MM:SS.uuuuuuZ
), regardless of the timezone specified in your application's timezone
configuration option. You are strongly encouraged to always use this serialization format, as well as to store your application's dates in the UTC timezone by not changing your application's timezone
configuration option from its default UTC
value. Consistently using the UTC timezone throughout your application will provide the maximum level of interoperability with other date manipulation libraries written in PHP and JavaScript.
If a custom format is applied to the date
or datetime
cast, such as datetime:Y-m-d H:i:s
, the inner timezone of the Carbon instance will be used during date serialization. Typically, this will be the timezone specified in your application's timezone
configuration option. However, it's important to note that timestamp
columns such as created_at
and updated_at
are exempt from this behavior and are always formatted in UTC, regardless of the application's timezone setting.
Enum Casting
Eloquent also allows you to cast your attribute values to PHP Enums. To accomplish this, you may specify the attribute and enum you wish to cast in your model's casts
method:
use App\Enums\ServerStatus; /** * Get the attributes that should be cast. * * @return array<string, string> */protected function casts(): array{ return [ 'status' => ServerStatus::class, ];}
Once you have defined the cast on your model, the specified attribute will be automatically cast to and from an enum when you interact with the attribute:
if ($server->status == ServerStatus::Provisioned) { $server->status = ServerStatus::Ready; $server->save();}
Casting Arrays of Enums
Sometimes you may need your model to store an array of enum values within a single column. To accomplish this, you may utilize the AsEnumArrayObject
or AsEnumCollection
casts provided by Laravel:
use App\Enums\ServerStatus;use Illuminate\Database\Eloquent\Casts\AsEnumCollection; /** * Get the attributes that should be cast. * * @return array<string, string> */protected function casts(): array{ return [ 'statuses' => AsEnumCollection::of(ServerStatus::class), ];}
Encrypted Casting
The encrypted
cast will encrypt a model's attribute value using Laravel's built-in encryption features. In addition, the encrypted:array
, encrypted:collection
, encrypted:object
, AsEncryptedArrayObject
, and AsEncryptedCollection
casts work like their unencrypted counterparts; however, as you might expect, the underlying value is encrypted when stored in your database.
As the final length of the encrypted text is not predictable and is longer than its plain text counterpart, make sure the associated database column is of TEXT
type or larger. In addition, since the values are encrypted in the database, you will not be able to query or search encrypted attribute values.
Key Rotation
As you may know, Laravel encrypts strings using the key
configuration value specified in your application's app
configuration file. Typically, this value corresponds to the value of the APP_KEY
environment variable. If you need to rotate your application's encryption key, you will need to manually re-encrypt your encrypted attributes using the new key.
Query Time Casting
Sometimes you may need to apply casts while executing a query, such as when selecting a raw value from a table. For example, consider the following query:
use App\Models\Post;use App\Models\User; $users = User::select([ 'users.*', 'last_posted_at' => Post::selectRaw('MAX(created_at)') ->whereColumn('user_id', 'users.id')])->get();
The last_posted_at
attribute on the results of this query will be a simple string. It would be wonderful if we could apply a datetime
cast to this attribute when executing the query. Thankfully, we may accomplish this using the withCasts
method:
$users = User::select([ 'users.*', 'last_posted_at' => Post::selectRaw('MAX(created_at)') ->whereColumn('user_id', 'users.id')])->withCasts([ 'last_posted_at' => 'datetime'])->get();
Custom Casts
Laravel has a variety of built-in, helpful cast types; however, you may occasionally need to define your own cast types. To create a cast, execute the make:cast
Artisan command. The new cast class will be placed in your app/Casts
directory:
php artisan make:cast Json
All custom cast classes implement the CastsAttributes
interface. Classes that implement this interface must define a get
and set
method. The get
method is responsible for transforming a raw value from the database into a cast value, while the set
method should transform a cast value into a raw value that can be stored in the database. As an example, we will re-implement the built-in json
cast type as a custom cast type:
<?php namespace App\Casts; use Illuminate\Contracts\Database\Eloquent\CastsAttributes;use Illuminate\Database\Eloquent\Model; class Json implements CastsAttributes{ /** * Cast the given value. * * @param array<string, mixed> $attributes * @return array<string, mixed> */ public function get(Model $model, string $key, mixed $value, array $attributes): array { return json_decode($value, true); } /** * Prepare the given value for storage. * * @param array<string, mixed> $attributes */ public function set(Model $model, string $key, mixed $value, array $attributes): string { return json_encode($value); }}
Once you have defined a custom cast type, you may attach it to a model attribute using its class name:
<?php namespace App\Models; use App\Casts\Json;use Illuminate\Database\Eloquent\Model; class User extends Model{ /** * Get the attributes that should be cast. * * @return array<string, string> */ protected function casts(): array { return [ 'options' => Json::class, ]; }}
Value Object Casting
You are not limited to casting values to primitive types. You may also cast values to objects. Defining custom casts that cast values to objects is very similar to casting to primitive types; however, the set
method should return an array of key / value pairs that will be used to set raw, storable values on the model.
As an example, we will define a custom cast class that casts multiple model values into a single Address
value object. We will assume the Address
value has two public properties: lineOne
and lineTwo
:
<?php namespace App\Casts; use App\ValueObjects\Address as AddressValueObject;use Illuminate\Contracts\Database\Eloquent\CastsAttributes;use Illuminate\Database\Eloquent\Model;use InvalidArgumentException; class Address implements CastsAttributes{ /** * Cast the given value. * * @param array<string, mixed> $attributes */ public function get(Model $model, string $key, mixed $value, array $attributes): AddressValueObject { return new AddressValueObject( $attributes['address_line_one'], $attributes['address_line_two'] ); } /** * Prepare the given value for storage. * * @param array<string, mixed> $attributes * @return array<string, string> */ public function set(Model $model, string $key, mixed $value, array $attributes): array { if (! $value instanceof AddressValueObject) { throw new InvalidArgumentException('The given value is not an Address instance.'); } return [ 'address_line_one' => $value->lineOne, 'address_line_two' => $value->lineTwo, ]; }}
When casting to value objects, any changes made to the value object will automatically be synced back to the model before the model is saved:
use App\Models\User; $user = User::find(1); $user->address->lineOne = 'Updated Address Value'; $user->save();
If you plan to serialize your Eloquent models containing value objects to JSON or arrays, you should implement the Illuminate\Contracts\Support\Arrayable
and JsonSerializable
interfaces on the value object.
Value Object Caching
When attributes that are cast to value objects are resolved, they are cached by Eloquent. Therefore, the same object instance will be returned if the attribute is accessed again.
If you would like to disable the object caching behavior of custom cast classes, you may declare a public withoutObjectCaching
property on your custom cast class:
class Address implements CastsAttributes{ public bool $withoutObjectCaching = true; // ...}
Array / JSON Serialization
When an Eloquent model is converted to an array or JSON using the toArray
and toJson
methods, your custom cast value objects will typically be serialized as well as long as they implement the Illuminate\Contracts\Support\Arrayable
and JsonSerializable
interfaces. However, when using value objects provided by third-party libraries, you may not have the ability to add these interfaces to the object.
Therefore, you may specify that your custom cast class will be responsible for serializing the value object. To do so, your custom cast class should implement the Illuminate\Contracts\Database\Eloquent\SerializesCastableAttributes
interface. This interface states that your class should contain a serialize
method which should return the serialized form of your value object:
/** * Get the serialized representation of the value. * * @param array<string, mixed> $attributes */public function serialize(Model $model, string $key, mixed $value, array $attributes): string{ return (string) $value;}
Inbound Casting
Occasionally, you may need to write a custom cast class that only transforms values that are being set on the model and does not perform any operations when attributes are being retrieved from the model.
Inbound only custom casts should implement the CastsInboundAttributes
interface, which only requires a set
method to be defined. The make:cast
Artisan command may be invoked with the --inbound
option to generate an inbound only cast class:
php artisan make:cast Hash --inbound
A classic example of an inbound only cast is a "hashing" cast. For example, we may define a cast that hashes inbound values via a given algorithm:
<?php namespace App\Casts; use Illuminate\Contracts\Database\Eloquent\CastsInboundAttributes;use Illuminate\Database\Eloquent\Model; class Hash implements CastsInboundAttributes{ /** * Create a new cast class instance. */ public function __construct( protected string|null $algorithm = null, ) {} /** * Prepare the given value for storage. * * @param array<string, mixed> $attributes */ public function set(Model $model, string $key, mixed $value, array $attributes): string { return is_null($this->algorithm) ? bcrypt($value) : hash($this->algorithm, $value); }}
Cast Parameters
When attaching a custom cast to a model, cast parameters may be specified by separating them from the class name using a :
character and comma-delimiting multiple parameters. The parameters will be passed to the constructor of the cast class:
/** * Get the attributes that should be cast. * * @return array<string, string> */protected function casts(): array{ return [ 'secret' => Hash::class.':sha256', ];}
Castables
You may want to allow your application's value objects to define their own custom cast classes. Instead of attaching the custom cast class to your model, you may alternatively attach a value object class that implements the Illuminate\Contracts\Database\Eloquent\Castable
interface:
use App\ValueObjects\Address; protected function casts(): array{ return [ 'address' => Address::class, ];}
Objects that implement the Castable
interface must define a castUsing
method that returns the class name of the custom caster class that is responsible for casting to and from the Castable
class:
<?php namespace App\ValueObjects; use Illuminate\Contracts\Database\Eloquent\Castable;use App\Casts\Address as AddressCast; class Address implements Castable{ /** * Get the name of the caster class to use when casting from / to this cast target. * * @param array<string, mixed> $arguments */ public static function castUsing(array $arguments): string { return AddressCast::class; }}
When using Castable
classes, you may still provide arguments in the casts
method definition. The arguments will be passed to the castUsing
method:
use App\ValueObjects\Address; protected function casts(): array{ return [ 'address' => Address::class.':argument', ];}
Castables & Anonymous Cast Classes
By combining "castables" with PHP's anonymous classes, you may define a value object and its casting logic as a single castable object. To accomplish this, return an anonymous class from your value object's castUsing
method. The anonymous class should implement the CastsAttributes
interface:
<?php namespace App\ValueObjects; use Illuminate\Contracts\Database\Eloquent\Castable;use Illuminate\Contracts\Database\Eloquent\CastsAttributes; class Address implements Castable{ // ... /** * Get the caster class to use when casting from / to this cast target. * * @param array<string, mixed> $arguments */ public static function castUsing(array $arguments): CastsAttributes { return new class implements CastsAttributes { public function get(Model $model, string $key, mixed $value, array $attributes): Address { return new Address( $attributes['address_line_one'], $attributes['address_line_two'] ); } public function set(Model $model, string $key, mixed $value, array $attributes): array { return [ 'address_line_one' => $value->lineOne, 'address_line_two' => $value->lineTwo, ]; } }; }}