README

Parentity is a package that allows the use of MTI (Multi-Table Inheritance) entities in Laravel 5.7+ using Eloquent models.

Installation

composer require "norse-blue/parentity"

Usage

1. Create parent model table with the following fields:

   $table->string('entity_type')->nullable();
   $table->unsignedInteger('entity_id')->nullable();

   Note: Use the proper id type for your child models (unsignedInteger, unsignedBigInteger, ...).

2. Create parent model that extends Models and uses IsMtiParentModeltrait:

   <?php
   
   namespace App;
   
   use App\Customers\Company;
   use App\Customers\Person;
   use Illuminate\Database\Eloquent\Model;
   use NorseBlue\Parentity\Traits\IsMtiParentModel;
   
   class Customer extends Model
   {
       use IsMtiParentModel;
   
       protected $fillable = [
           'name',
       ];
   
       /** @optional */
       protected $childTypeAliases = [
           'person' => Person::class,
           'company' => Company::class,
       ];
   
       /** @optional */
       protected $ownAttributes = [
           'id',
           'name',
           'entity_type',
           'entity_id',
       ];
   }

   Notes:

   • The $childTypeAliases array is optional. It allows to create child models using an alias instead of the full qualified class name.
   • The $ownAttributes array is optional. It allows the proxying of get and set calls between parent and child models (instead of $customer->entity->last_name it allows to use $customer->last_name). It is recommended to specify this array so that everything works neatly.

3. Create the child model(s) that extends Models and uses IsMtiChildModel trait:

   <?php
   
   namespace App;
   
   use App\Customer;
   use Illuminate\Database\Eloquent\Model;
   use NorseBlue\Parentity\Traits\IsMtiChildModel;
   
   class Person extends Model
   {
       use IsMtiChildModel;
       
       protected $parentModel = Customer::class;
   
       protected $parentEntity = 'entity';
   
       protected $fillable = [
           'last_name',
       ];
   }

   Notes:

   • All fields are mandatory so that the child model knows how to access the parent model.

Model creation

Creating a model from the parent class

To create a model from the parent class you need to specify the entity type before the attributes.

$customer = Customer::create(Person::class, [
    'name' => 'Axel',
    'last_name' => 'Pardemann',
]);

Creating a model from the child class

The best way to create a model is from the child classes. Just include all the models (parent and child) attributes.

$person = Person::create([
    'name' => 'Axel',
    'last_name' => 'Pardemann',
]);

In both cases a parent and a linked child will be created with the given attribute values, which will be stored in each model's table.

Model properties

There are two ways that we can access the model properties: explicitly or implicitly.

Explicit properties

When using explicit properties we explicitly ask for the parent or the entity property:

// using the previously created models

// Explicit property from the parent model
echo $customer->name . " " . $customer->entity->last_name;

// Explicit property from the child model
echo $person->parent->name . " " . $person->last_name;

Outputs:

Axel Pardemann
Axel Pardemann

Implicit properties

If set up correctly, instead of using the explicit property calls we can use the shorter version which implicitly proxies the call to the parent or child model:

// using the previously created models

// Implicit property from the parent model
echo $customer->name . " " . $customer->last_name;

// Implicit property from the child model
echo $person->name . " " . $person->last_name;

Outputs:

Axel Pardemann
Axel Pardemann

Code status and known issues

• This package is still a proof of concept. At the moment we can only create models and use the properties.
• It is planned to extend the functionality to the make, update and save methods first.

Contributing

Please see CONTRIBUTING for details.