PHP - Iteration Over $this And Inheritance

class MyProductClass
{
    function computeProductA()
    {
        doSometing();
    }

    function computeProductB()
    {
        doSometingElse();
        $this->computeProductCommon();
    }

    function computeProductC()
    {
        $this->computeProductCommon();
    }

    function computeProductCommon()
    {
    }
}

Context.

Class AbstractTenantEntity's purpose is to restrict access to data to the tenant (i.e. account, owner, etc) that owns the data.  Any entity which extends it will have the TenantId added when created and the TenantId in the WHERE clause for all other requests.

Tenant typically does not have collections of the various entities which extend AbstractTenantEntity, but does for a few of them do.  When using annotation, I handled it by applying Doctrine's AssociationOverride annotation to the extended classes which should have a collection in Tenant.

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity()
 */
class Tenant
{
    /**
     * @ORM\OneToMany(targetEntity=Asset::class, mappedBy="tenant")
     */
    private $assets;

    // Other properties and typical getters and setters
}

use Doctrine\ORM\Mapping as ORM;

abstract class AbstractTenantEntity implements TenantInterface
{
    /**
     * inversedBy performed in child where required
     * @ORM\ManyToOne(targetEntity=Tenant::class)
     * @ORM\JoinColumn(nullable=false)
     */
    protected ?Tenant $tenant = null;

    // Typical getters and setters
}

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity()
 * @ORM\AssociationOverrides({
 *     @ORM\AssociationOverride(name="tenant", inversedBy="assets")
 * })
 */
class Asset extends PublicIdTenantEntity
{
    // Various properties and typical getters and setters
}

So, now I am changing from annotations to attributes, and modified AbstractTenantEntity as follows:

use Doctrine\ORM\Mapping\ManyToOne;
use Doctrine\ORM\Mapping\JoinColumn;

abstract class AbstractTenantEntity implements TenantInterface
{
    /**
     * inversedBy performed in child where required
     */
    #[ManyToOne(targetEntity: Tenant::class)]
    #[JoinColumn(nullable: false)]
    protected ?Tenant $tenant = null;

    // Typical getters and setters
}

Next I went to modify Asset and realized that there didn't appear to be an attribute for AssociationOverride.  I found a little discussion on the topic on github but couldn't find any resolution.

Question

Can inheritance be used with PHP 8 attributes where the property is defined in the parent class and the attribute is applied in the child class?  Googling php 8 attributes inheritance didn't provide anything and thus I expect the answer is no but thought I'd ask.

Thanks

EDIT.  Maybe Doctrine does have an attribute version: https://github.com/doctrine/orm/blob/2.9.x/lib/Doctrine/ORM/Mapping/AttributeOverride.php

EDIT2.  Actually don't think so

I am using API-Platform, Doctrine, and Symfony with entities that utilize class type inheritance to extend an abstract entity.

I've been running into one issue after another primarily related to the serialization process (serialization groups, parent annotations not propagated to the child, etc), and while I am sure user error on my part is part of the culprit, it appears that API-Platform and potentially Symfony and Doctrine don't fully support entity inheritance.  My reason for thinking so is the incredibly sparse amount of documentation on the subject and remarks on quite a few github issues posts and other blogs how it is "bad practice".

For instance, say I have Mouse, Cat, and Dog which all extend AbstractAnimal, and each has a bunch of common properties such as birthday, weight, etc, and methods such as eats(), sleeps(), etc.  Sorry in advance for using hypothetical entities but I don't think doing so distracts.  I like how inheritance allows me to keep all common properties in a single table, but can let that go.  More importantly, the subset mouse, cat, and dog table shares an ID from the animal table allowing me to associate all animals to some other table (i.e. many-to-one to person whether they are their pet or many-to-many to country whether they are native to a country), and to retrieve a list of animals and filter by some property or type as needed without a bunch of unions.

To me, this sounds like inheritance, but if the products I am using don't support it very well, it doesn't matter.

First question.  Is entity inheritance considered bad practice?  And even if not, is it common for frameworks to limit their level of support for them?

If so, what can I do about it?  Maybe favor composition over inheritance?  Okay, great, I now have a single animal table which makes all my SQL concerns issues go away and I am pretty confident that my serialization issues will also go away. All I need to do is inject each animal with some "thing" to make them a mouse, cat, or dog.

But what do I call this thing?  I've struggled with this topic for a while and asked the same question regarding how to deal with BarCharts, PieCharts, GaugeCharts, LineCharts, etc all being charts but all acting slightly differently, and never really came to any conclusion.

For a non-hypothetical scenario, I have BacnetGateway and ModbusGateway which extend AbstractGateway.  Okay, this one is easy and I change to just having a Gateway and inject either BacnetProtocol or ModbusProtocol.

For another non-hypothetical scenario, I have PhysicalPoint which represents some real environmental parameter, VirtualPoint which represents combining one or more PhysicalPoints or VirtualPoints, and TransformedPoint (feel free to provide a better name) which represents performing some time function such as integrating over a given time.  Currently, they all extend AbstractPoint, but if I was trying to do so with composition, I could inject PointType but don't think doing so makes sense.

For my hypothetical scenario, do I make a DNA interface and inject an Animal with DogDNA to get a dog?

I really need to get my head around this once and for all.  Thanks

I wish to create and store in a DB three objects which are created using injection;

$myAObject=new BaseEntity(new InjectedThingA());
$myBObject=new BaseEntity(new InjectedThingB());
$myCObject=new BaseEntity(new InjectedThingC());

BaseEntity is defined by SQL table base_entity and my three injected objects InjectedThingA,  InjectedThingB, and InjectedThingC are each defined by SQL tables injected_thing_a, injected_thing_b, injected_thing_c, respectively.  Each of these injected tables has autoincrement column id plus whatever other columns, and base_entity includes a column injected_thing_id.  But this won't work since this ID is not unique across InjectedThings and also poor since there is no foreign key, so instead I do the following.

InjectedThingA extends AbstractInjectedThing
InjectedThingB extends AbstractInjectedThing
InjectedThingC extends AbstractInjectedThing

Then I add an autoincrement id column to AbstractedInjectedThing and place a one-to-one constraint from column id in InjectedThingA,  InjectedThingB, and InjectedThingC to column id in AbstractedInjectedThing.

So, I still need to use inheritance, right?  I don't think that this type of inheritance brings the baggage which MyInheritedEntity extends BaseEntity does and I am okay with it, but just want to make sure I am doing this right.

Thanks

Trying to create a model where Parent1 and Parent2 extend Grandparent, and Child1_1 and Child1_2 extend Parent1 as well as Child2_1 and Child2_2 extend Parent2.

I set up my definitions:

Grandparent:
    type: entity
    table: grandparent_table
    inheritanceType: JOINED
    discriminatorColumn:
        name: discriminator_column_grandparent
        type: string
    repositoryClass: GrandParent
    id:
        id:
            type: integer
            generator:
                strategy: AUTO
    fields:
        GrandParent_Item1:
            type: string
        GrandParent_Item2:
            type: string
Parent1:
    type: entity
    table: parent_table1
    extends: Grandparent
    inheritanceType: JOINED
    discriminatorColumn:
        name: discriminator_column_parent1
        type: string
    id:
        id:
            associationKey: true
    fields:
        Parent1_Item1:
            type: string
        Parent1_Item2:
            type: string
Parent2:
    type: entity
    table: parent_table2
    extends: Grandparent
    inheritanceType: JOINED
    discriminatorColumn:
        name: discriminator_column_parent2
        type: string
    id:
        id:
            associationKey: true
    fields:
        Parent2_Item1:
            type: string
        Parent2_Item2:
            type: string
Child1_1:
    extends: Parent1
    type: entity
    table: child1_1_table
    id:
        id:
            associationKey: true
    fields:
        Child1_1_Item1:
            type: string
        Child1_1_Item2:
            type: string
Child1_2:
    extends: Parent1
    type: entity
    table: child1_2_table
    id:
        id:
            associationKey: true
    fields:
        Child1_2_Item1:
            type: string
        Child1_2_Item2:
            type: string
Child2_1:
    extends: Parent2
    type: entity
    table: child2_1_table
    id:
        id:
            associationKey: true
    fields:
        Child2_1_Item1:
            type: string
        Child2_1_Item2:
            type: string
Child2_2:
    extends: Parent2
    type: entity
    table: child2_2_table
    id:
        id:
            associationKey: true
    fields:
        Child2_2_Item1:
            type: string
        Child2_2_Item2:
            type: string

 And then generate my entities:       

$ vendor/bin/doctrine orm:generate-entities -vvv src

 Processing entity "Child1_1"
 Processing entity "Child1_2"
 Processing entity "Child2_1"
 Processing entity "Child2_2"
 Processing entity "Grandparent"
 Processing entity "Parent1"
 Processing entity "Parent2"


 [OK] Entity classes generated to "/var/www/doctrine/src"

Note that I needed to manually edit the Parent1 and 2 classes to extend Grandparent as well as the individual Child classes to extend their applicable Parent.

Next, I create the schema:

$ vendor/bin/doctrine orm:schema-tool:create --dump-sql

 The following SQL statements will be executed:

     CREATE TABLE child1_1_table (id INT NOT NULL, Child1_1_Item1 VARCHAR(255) NOT NULL, Child1_1_Item2 VARCHAR(255) NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB;
     CREATE TABLE child1_2_table (id INT NOT NULL, Child1_2_Item1 VARCHAR(255) NOT NULL, Child1_2_Item2 VARCHAR(255) NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB;
     CREATE TABLE child2_1_table (id INT NOT NULL, Child2_1_Item1 VARCHAR(255) NOT NULL, Child2_1_Item2 VARCHAR(255) NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB;
     CREATE TABLE child2_2_table (id INT NOT NULL, Child2_2_Item1 VARCHAR(255) NOT NULL, Child2_2_Item2 VARCHAR(255) NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB;
     CREATE TABLE grandparent_table (id INT AUTO_INCREMENT NOT NULL, GrandParent_Item1 VARCHAR(255) NOT NULL, GrandParent_Item2 VARCHAR(255) NOT NULL, discriminator_column_grandparent VARCHAR(255) NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB;
     CREATE TABLE parent_table1 (id INT NOT NULL, Parent1_Item1 VARCHAR(255) NOT NULL, Parent1_Item2 VARCHAR(255) NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB;
     CREATE TABLE parent_table2 (id INT NOT NULL, Parent2_Item1 VARCHAR(255) NOT NULL, Parent2_Item2 VARCHAR(255) NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB;
     ALTER TABLE child1_1_table ADD CONSTRAINT FK_3445750EBF396750 FOREIGN KEY (id) REFERENCES grandparent_table (id) ON DELETE CASCADE;
     ALTER TABLE child1_2_table ADD CONSTRAINT FK_5AD6F93BF396750 FOREIGN KEY (id) REFERENCES grandparent_table (id) ON DELETE CASCADE;
     ALTER TABLE child2_1_table ADD CONSTRAINT FK_DC849CBBF396750 FOREIGN KEY (id) REFERENCES grandparent_table (id) ON DELETE CASCADE;
     ALTER TABLE child2_2_table ADD CONSTRAINT FK_3C205356BF396750 FOREIGN KEY (id) REFERENCES grandparent_table (id) ON DELETE CASCADE;
     ALTER TABLE parent_table1 ADD CONSTRAINT FK_5386E15BBF396750 FOREIGN KEY (id) REFERENCES grandparent_table (id) ON DELETE CASCADE;
     ALTER TABLE parent_table2 ADD CONSTRAINT FK_CA8FB0E1BF396750 FOREIGN KEY (id) REFERENCES grandparent_table (id) ON DELETE CASCADE;

I see how Grandparent has discriminatorColumn discriminator_column_grandparent as expected.

But why doesn't Parent1 and Parent2 have discriminatorColumn's discriminator_column_parent1 and discriminator_column_parent2?

Note that I've also tried making Grandparent, Parent1, and Parent2 abstract but get the same results.  I've also messed around with Mapped Superclasses, but I don't think they are applicable for my use (correct me if you think I am wrong).

Thanks!

I am doing something stupid, and just can't see it and hoping someone has better eyes than mine.  I have two Doctrine entities which extend another class using single class inheritance, but when retrieving the collection of either of the two child classes, I get the collection of the parent (i.e. combination of both child classes).  I've experimented with making the parent abstract and not including it in the discriminator map but no change.  In hopes to identifying my mistake, I created a new Symfony project with just the relevant classes and show all steps below.

Initial install by running the following:

symfony new test
composer update
composer require doctrine/orm
composer require migrations
composer require maker --dev
composer require security

Using "php bin/console make:user", I created three users: AbstractUser, OwnerUser, VendorUser.  I then edited all three entities and the owner and vendor repositories as follows:

<?php

namespace App\Entity;

use App\Repository\AbstractUserRepository;
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Security\Core\User\UserInterface;

/**
 * @ORM\Entity(repositoryClass=AbstractUserRepository::class)
 * @ORM\InheritanceType("SINGLE_TABLE")
 * @ORM\DiscriminatorColumn(name="discr", type="string")
 * @ORM\DiscriminatorMap({"owner" = "OwnerUser", "vendor" = "VendorUser", "abstract" = "AbstractUser"})
 */
class AbstractUser implements UserInterface
{
    // No changes made
}

<?php

namespace App\Entity;

use App\Repository\OwnerUserRepository;
use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity(repositoryClass=OwnerUserRepository::class)
 */
class OwnerUser extends AbstractUser
{
}

<?php

namespace App\Entity;

use App\Repository\VendorUserRepository;
use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity(repositoryClass=VendorUserRepository::class)
 */
class VendorUser extends AbstractUser
{
}

No change to AbstractUserRepository.

<?php

namespace App\Repository;

class OwnerUserRepository extends AbstractUserRepository
{
}

<?php

namespace App\Repository;

class VendorUserRepository extends AbstractUserRepository
{
}

Then I migrated the DB.

php bin/console doctrine:schema:drop --full-database --force
rm migrations/*
php bin/console make:migration
php bin/console doctrine:migrations:migrate

Next I created two OwnerUsers and one VendorUser using a command script I wrote shown at the end of this post.

# php bin/console app:tester create OwnerUser roles=[]
# php bin/console app:tester create OwnerUser roles=[]
# php bin/console app:tester create VendorUser roles=[]

Checked the PostSQL database.

facdocs=> \d
                     List of relations
 Schema |            Name             |   Type   |  Owner
--------+-----------------------------+----------+---------
 public | abstract_user               | table    | facdocs
 public | abstract_user_id_seq        | sequence | facdocs
 public | doctrine_migration_versions | table    | facdocs
(3 rows)

facdocs=> select * from abstract_user;
 id |    email    | roles |    password    | discr
----+-------------+-------+----------------+--------
  1 | setEmail158 | []    | setPassword146 | owner
  2 | setEmail87  | []    | setPassword101 | owner
  3 | setEmail62  | []    | setPassword20  | vendor
(3 rows)

facdocs=>

Next, I retrieved the entities using Doctrine along with the beforementioned test script.
 

[michael@devserver test]$ php bin/console app:tester read VendorUser
Test Entity Manager
============

command: read
entity: VendorUser
class: \App\Entity\VendorUser
properties: []
array(3) {
  [0]=>
  object(stdClass)#293 (5) {
    ["__CLASS__"]=>
    string(20) "App\Entity\OwnerUser"
    ["id:App\Entity\AbstractUser:private"]=>
    int(1)
    ["email:App\Entity\AbstractUser:private"]=>
    string(11) "setEmail158"
    ["roles:App\Entity\AbstractUser:private"]=>
    string(8) "Array(0)"
    ["password:App\Entity\AbstractUser:private"]=>
    string(14) "setPassword146"
  }
  [1]=>
  object(stdClass)#294 (5) {
    ["__CLASS__"]=>
    string(20) "App\Entity\OwnerUser"
    ["id:App\Entity\AbstractUser:private"]=>
    int(2)
    ["email:App\Entity\AbstractUser:private"]=>
    string(10) "setEmail87"
    ["roles:App\Entity\AbstractUser:private"]=>
    string(8) "Array(0)"
    ["password:App\Entity\AbstractUser:private"]=>
    string(14) "setPassword101"
  }
  [2]=>
  object(stdClass)#358 (5) {
    ["__CLASS__"]=>
    string(21) "App\Entity\VendorUser"
    ["id:App\Entity\AbstractUser:private"]=>
    int(3)
    ["email:App\Entity\AbstractUser:private"]=>
    string(10) "setEmail62"
    ["roles:App\Entity\AbstractUser:private"]=>
    string(8) "Array(0)"
    ["password:App\Entity\AbstractUser:private"]=>
    string(13) "setPassword20"
  }
}
[michael@devserver test]$
[michael@devserver test]$ php bin/console app:tester read OwnerUser
Test Entity Manager
============

command: read
entity: OwnerUser
class: \App\Entity\OwnerUser
properties: []
array(3) {
  [0]=>
  object(stdClass)#293 (5) {
    ["__CLASS__"]=>
    string(20) "App\Entity\OwnerUser"
    ["id:App\Entity\AbstractUser:private"]=>
    int(1)
    ["email:App\Entity\AbstractUser:private"]=>
    string(11) "setEmail158"
    ["roles:App\Entity\AbstractUser:private"]=>
    string(8) "Array(0)"
    ["password:App\Entity\AbstractUser:private"]=>
    string(14) "setPassword146"
  }
  [1]=>
  object(stdClass)#294 (5) {
    ["__CLASS__"]=>
    string(20) "App\Entity\OwnerUser"
    ["id:App\Entity\AbstractUser:private"]=>
    int(2)
    ["email:App\Entity\AbstractUser:private"]=>
    string(10) "setEmail87"
    ["roles:App\Entity\AbstractUser:private"]=>
    string(8) "Array(0)"
    ["password:App\Entity\AbstractUser:private"]=>
    string(14) "setPassword101"
  }
  [2]=>
  object(stdClass)#358 (5) {
    ["__CLASS__"]=>
    string(21) "App\Entity\VendorUser"
    ["id:App\Entity\AbstractUser:private"]=>
    int(3)
    ["email:App\Entity\AbstractUser:private"]=>
    string(10) "setEmail62"
    ["roles:App\Entity\AbstractUser:private"]=>
    string(8) "Array(0)"
    ["password:App\Entity\AbstractUser:private"]=>
    string(13) "setPassword20"
  }
}
[michael@devserver test]$

As seen, when requesting a collection of either OwnerUsers or VendorUsers, I am retrieving the combination of both collections.  I am sure it is totally user (i.e. me) error, but just don't see it.  Are you able to see my stupid mistake?  Thanks

My test script is below:
 

<?php

namespace App\Command;

use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;
use Symfony\Component\Console\Input\InputArgument;
use Doctrine\ORM\EntityManagerInterface;
use Doctrine\Common\Util\Debug;

class Tester extends Command
{
    // the name of the command (the part after "bin/console")
    protected static $defaultName = 'app:tester';
    private $entityManager;
    public function __construct(EntityManagerInterface $entityManager)
    {
        $this->entityManager = $entityManager;
        parent::__construct();
    }

    protected function configure()
    {
        $this
        ->setDescription('Doctrine Object Tester.  --help')
        ->setHelp('This command allows you to query a single entity...')
        ->addArgument('cmd', InputArgument::REQUIRED, 'The command name [create, read].')
        ->addArgument('entity', InputArgument::REQUIRED, 'The name of the entity.')
        ->addArgument('properties', InputArgument::IS_ARRAY | InputArgument::OPTIONAL, 'properies (foo=foo bla=[]')
        ;
    }

    private function getProperties($input)
    {
        $properties=[];
        foreach($input as $property) {
            $property=explode('=', $property);
            $name = trim($property[0]);
            $value = trim($property[1]);
            if($value === '[]') {
                $value = [];
            }
            elseif($value === 'null') {
                $value = null;
            }
            elseif(substr($value, 0, 1) === '/') {
                $value = explode('/', substr($value, 1));
                $class = ucfirst(substr($value[0], 0, -1));
                $class = '\App\Entity\\'.$class;
                if(count($value)===1) {
                    $value = $this->entityManager->getRepository($class)->findAll();
                }
                else {
                    $value = $this->entityManager->getRepository($class)->find($value[1]);
                }
            }
            $properties[$name] = $value;
        }
        return $properties;
    }

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $output->writeln([
            'Test Entity Manager',
            '============',
            '',
        ]);

        // retrieve the argument value using getArgument()

        $cmd = $input->getArgument('cmd');
        $output->writeln('command: '.$cmd);
        $entity = $input->getArgument('entity');
        $output->writeln('entity: '.$entity);
        $class = '\App\Entity\\'.$entity;
        $output->writeln('class: '.$class);
        $properties = $this->getProperties($input->getArgument('properties'));

        $output->writeln('properties: '.json_encode($properties));

        switch($cmd) {
            case 'create':
                $entity = new $class;
                foreach(get_class_methods($entity) as $method) {
                    if(substr($method, 0, 3)==='set') {
                        $m = lcfirst(substr($method, 3));
                        $entity->$method(array_key_exists($m, $properties)?$properties[$m]:$method.rand(0,200));
                    }
                }
                $this->entityManager->persist($entity);
                $this->entityManager->flush();
                $output->writeln('entity created');
                break;
            case 'read':
                Debug::dump($this->entityManager->getRepository($class)->findAll());
                break;
            default:
                $output->writeln('INVALID COMMAND: '.$cmd.'.  Only create and read are supported.'); 
        }
        return Command::SUCCESS;
    }
}

For solely to reduce duplicated code and when injection isn't applicable, should one use inheritance or traits?

<?php
abstract class BaseClass
{
    private $id, $name;
    public function __construct(int $id, string $name) {
        $this->id=$id;
        $this->name=$name;
    }

    public function getId():int
    {
        return $this->id;
    }

    public function getName():string
    {
        return $this->name;
    }
}

<?php
class A extends BaseClass{}
class B extends BaseClass{}
class C extends BaseClass
{
    private $foo;
    public function __construct(int $id, string $name, Foo $foo) {
        parent::__construct($id, $name);
        $this->foo=$foo;
    }
    public function getFoo():Foo {
        return $this->foo;
    }
}

<?php
trait MyTrait
{
    private $id, $name;
    public function __construct(int $id, string $name) {
        $this->id=$id;
        $this->name=$name;
    }

    public function getId():int
    {
        return $this->id;
    }

    public function getName():string
    {
        return $this->name;
    }
}

<?php
class A
{
    use MyTrait;
}
class B
{
    use MyTrait;
}
class C
{
    use MyTrait;
    private $foo;
    public function __construct(int $id, string $name, Foo $foo) {
        $this->id=$id;
        $this->name=$name;
        $this->foo=$foo;
    }
    public function getFoo():Foo {
        return $this->foo;
    }
}