Add additional table prototype for json string array

[alexander-schranz]

This pull request contains a lot of hacks, but good for a prototype. It generates a dynamic class which will generate a table instead of json array.

TODO

• Move generating of Proxy Classes to compilerpass
  • Alternative listen to onClassMetadataNotFound exception
  • Find out how to access mapping configuration in compilerpass
  • Remove custom ClassMetadataFactory with duplicated getAllmetadata call
• Implement MEMBER OF query method which should join the additional table

Version A (move json to own to many table)

• Convert $locales array to collection on persist / update
• Convert $locales collection to array on load

Version B (duplicate data to additional table)

• Keep json field
• Add additional $localeCollection only for filter query
• Add ore remove locales on Persist / Update events check over unit of work diff

The entity should register the array field the following way:

    /**
     * @var iterable<\Stringable|string>
     *
     * @ORM\Column(type="json", options={"string-array": true})
     */
    private $locales;

The metadata loader will convert the json into a additonal table with a stringable entity.

CREATE TABLE event (id INT AUTO_INCREMENT NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB;
CREATE TABLE page (id INT AUTO_INCREMENT NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB;

CREATE TABLE page_locales (string VARCHAR(255) NOT NULL, object_id INT NOT NULL, INDEX IDX_1FFBBF2E232D562B (object_id), INDEX idx_string (string), INDEX idx_object_string (string, object_id), PRIMARY KEY(object_id, string)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB;

CREATE TABLE event_locales (string VARCHAR(255) NOT NULL, object_id INT NOT NULL, INDEX IDX_60CCFD14232D562B (object_id), INDEX idx_string (string), INDEX idx_object_string (string, object_id), PRIMARY KEY(object_id, string)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB;

ALTER TABLE page_locales ADD CONSTRAINT FK_1FFBBF2E232D562B FOREIGN KEY (object_id) REFERENCES page (id) ON DELETE CASCADE;
ALTER TABLE event_locales ADD CONSTRAINT FK_60CCFD14232D562B FOREIGN KEY (object_id) REFERENCES event (id) ON DELETE CASCADE;

A proxy class which implements \Stringable is created which looks like the following:

The proxy class name is a sha1 hash over the related entity full qualified class name plus the related field name.

<?php

namespace ORMArrayProxy;

use Doctrine\ORM\Mapping\Builder\ClassMetadataBuilder;
use Doctrine\ORM\Mapping\ClassMetadata;

/**
 * @internal
 */
class Proxy_0607a2d5cae4c928270cdaf51534266e1871bb19 implements \Stringable
{
    /**
     * @var null|string
     */
    public static $targetEntity = 'App\Entity\Page';

    /**
     * @var null|string
     */
    public static $inversedBy = 'locales';

    /**
     * @var null|string
     */
    public static $tableName = 'page_locales';

    /**
     * @var null|string
     */
    public static $referenceColumn =  'id';
    
    /**
     * @var object
     */
    protected $object;

    /**
     * @var string
     */
    protected $string = '';

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

    public static function loadMetadata(ClassMetadata $metadata)
    {
        $builder = new ClassMetadataBuilder($metadata);

        $builder->setTable(static::$tableName);

        $builder->createManyToOne(
            'object',
            static::$targetEntity
        )
            ->inversedBy(static::$inversedBy)
            ->addJoinColumn(
                'object_id',
                static::$referenceColumn,
                true,
                false,
                'CASCADE'
            )
            ->makePrimaryKey()
            ->build();

        $builder->createField('string', 'string')
            ->columnName('string')
            ->makePrimaryKey()
            ->build();

        $builder->addIndex(['string'], 'idx_string');
        $builder->addIndex(['string', 'object_id'], 'idx_object_string');
    }
}