Eloquent: Serialization

Introduction

When building JSON APIs, you will often need to convert your models and relationships to arrays or JSON. Eloquent includes convenient methods for making these conversions, as well as controlling which attributes are included in your serializations.

Serializing Models & Collections

Serializing To Arrays

To convert a model and its loaded relationships to an array, you should use the toArray method. This method is recursive, so all attributes and all relations (including the relations of relations) will be converted to arrays:

$user = App\User::with('roles')->first();

return $user->toArray();

You may also convert entire collections of models to arrays:

$users = App\User::all();

return $users->toArray();

Serializing To JSON

To convert a model to JSON, you should use the toJson method. Like toArray, the toJson method is recursive, so all attributes and relations will be converted to JSON. You may also specify JSON encoding options supported by PHP:

$user = App\User::find(1);

return $user->toJson();

return $user->toJson(JSON_PRETTY_PRINT);

Alternatively, you may cast a model or collection to a string, which will automatically call the toJson method on the model or collection:

$user = App\User::find(1);

return (string) $user;

Since models and collections are converted to JSON when cast to a string, you can return Eloquent objects directly from your application's routes or controllers:

Route::get('users', function () {
    return App\User::all();
});

Hiding Attributes From JSON

Sometimes you may wish to limit the attributes, such as passwords, that are included in your model's array or JSON representation. To do so, add a $hidden property to your model:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = ['password'];
}

备注

When hiding relationships, use the relationship's method name.

Alternatively, you may use the visible property to define a white-list of attributes that should be included in your model's array and JSON representation. All other attributes will be hidden when the model is converted to an array or JSON:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    /**
     * The attributes that should be visible in arrays.
     *
     * @var array
     */
    protected $visible = ['first_name', 'last_name'];
}

Temporarily Modifying Attribute Visibility

If you would like to make some typically hidden attributes visible on a given model instance, you may use the makeVisible method. The makeVisible method returns the model instance for convenient method chaining:

return $user->makeVisible('attribute')->toArray();

Likewise, if you would like to make some typically visible attributes hidden on a given model instance, you may use the makeHidden method.

return $user->makeHidden('attribute')->toArray();

Appending Values To JSON

Occasionally, when casting models to an array or JSON, you may wish to add attributes that do not have a corresponding column in your database. To do so, first define an accessor for the value:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    /**
     * Get the administrator flag for the user.
     *
     * @return bool
     */
    public function getIsAdminAttribute()
    {
        return $this->attributes['admin'] == 'yes';
    }
}

After creating the accessor, add the attribute name to the appends property on the model. Note that attribute names are typically referenced in "snake case", even though the accessor is defined using "camel case":

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    /**
     * The accessors to append to the model's array form.
     *
     * @var array
     */
    protected $appends = ['is_admin'];
}

Once the attribute has been added to the appends list, it will be included in both the model's array and JSON representations. Attributes in the appends array will also respect the visible and hidden settings configured on the model.

Appending At Run Time

You may instruct a single model instance to append attributes using the append method. Or, you may use the setAppends method to override the entire array of appended properties for a given model instance:

return $user->append('is_admin')->toArray();

return $user->setAppends(['is_admin'])->toArray();

Date Serialization

Customizing The Date Format Per Attribute

You may customize the serialization format of individual Eloquent date attributes by specifying the date format in the cast declaration:

protected $casts = [
    'birthday' => 'date:Y-m-d',
    'joined_at' => 'datetime:Y-m-d H:00',
];

Global Customization Via Carbon

Laravel extends the Carbon date library in order to provide convenient customization of Carbon's JSON serialization format. To customize how all Carbon dates throughout your application are serialized, use the Carbon::serializeUsing method. The serializeUsing method accepts a Closure which returns a string representation of the date for JSON serialization:

<?php

namespace App\Providers;

use Illuminate\Support\Carbon;
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Perform post-registration booting of services.
     *
     * @return void
     */
    public function boot()
    {
        Carbon::serializeUsing(function ($carbon) {
            return $carbon->format('U');
        });
    }

    /**
     * Register bindings in the container.
     *
     * @return void
     */
    public function register()
    {
        //
    }
}