Parental is a Laravel package that brings STI (Single Table Inheritance) capabilities to Eloquent.
It's a fancy name for a simple concept: Extending a model (usually to add specific behavior), but referencing the same table.
composer require "calebporzio/parental=0.9"
// The "parent"
class User extends Model
{
//
}
// The "child"
class Admin extends User
{
use \Parental\HasParent;
public function impersonate($user) {
...
}
}
// Returns "Admin" model, but reference "users" table:
$admin = Admin::first();
// Can now access behavior exclusive to "Admin"s
$admin->impersonate($user);
Without Parental, calling Admin::first()
would throw an error because Laravel would be looking for an admins
table. Laravel generates expected table names, as well as foreign keys and pivot table names, using the model's class name. By adding the HasParent
trait to the Admin model, Laravel will now reference the parent model's class name users
.
// First, we need to create a `type` column on the `users` table
Schema::table('users', function ($table) {
$table->string('type')->nullable();
});
// The "parent"
class User extends Model
{
use \Parental\HasChildren;
protected $fillable = ['type'];
}
// A "child"
class Admin extends User
{
use \Parental\HasParent;
}
// Another "child"
class Guest extends User
{
use \Parental\HasParent;
}
// Adds row to "users" table with "type" column set to: "App/Admin"
Admin::create(...);
// Adds row to "users" table with "type" column set to: "App/Guest"
Guest::create(...);
// Returns 2 model instances: Admin, and Guest
User::all();
Before, if we ran: User::first()
we would only get back User
models. By adding the HasChildren
trait and a type
column to the users
table, running User::first()
will return an instance of the child model (Admin
or Guest
in this case).
If you don't want to store raw class names in the type column, you can override them using the $childTypes
property.
class User extends Model
{
use \Parental\HasChildren;
protected $fillable = ['type'];
protected $childTypes = [
'admin' => App\Admin::class,
'guest' => App\Guest::class,
];
}
Now, running Admin::create()
will set the type
column in the users
table to admin
instead of App\Admin
.
This feature is useful if you are working with an existing type column, or if you want to decouple application details from your database.
You can override the default type column by setting the $childColumn
property on the parent model.
class User extends Model
{
use \Parental\HasChildren;
protected $fillable = ['parental_type'];
protected $childColumn = 'parental_type';
}
If you want to use share parent Nova resources with child models, you may register the following provider at the end of the boot method of your NovaServiceProvider:
class NovaServiceProvider extends NovaApplicationServiceProvider
{
public function boot() {
parent::boot();
// ...
$this->app->register(\Parental\Providers\NovaResourceProvider::class);
}
}
Thanks to @sschoger for the sick logo design, and @DanielCoulbourne for helping brainstorm the idea on Twenty Percent Time.