21. YAML Mapping

The YAML mapping driver enables you to provide the ORM metadata in form of YAML documents.

The YAML mapping document of a class is loaded on-demand the first time it is requested and subsequently stored in the metadata cache. In order to work, this requires certain conventions:

  • Each entity/mapped superclass must get its own dedicated YAML mapping document.
  • The name of the mapping document must consist of the fully qualified name of the class, where namespace separators are replaced by dots (.).
  • All mapping documents should get the extension ”.dcm.yml” to identify it as a Doctrine mapping file. This is more of a convention and you are not forced to do this. You can change the file extension easily enough.
<?php
$driver->setFileExtension('.yml');

It is recommended to put all YAML mapping documents in a single folder but you can spread the documents over several folders if you want to. In order to tell the YamlDriver where to look for your mapping documents, supply an array of paths as the first argument of the constructor, like this:

<?php
use Doctrine\ORM\Mapping\Driver\YamlDriver;

// $config instanceof Doctrine\ORM\Configuration
$driver = new YamlDriver(array('/path/to/files'));
$config->setMetadataDriverImpl($driver);

21.1. Simplified YAML Driver

The Symfony project sponsored a driver that simplifies usage of the YAML Driver. The changes between the original driver are:

  • File Extension is .orm.yml
  • Filenames are shortened, “MyProject\Entities\User” will become User.orm.yml
  • You can add a global file and add multiple entities in this file.

Configuration of this client works a little bit different:

<?php
$namespaces = array(
    '/path/to/files1' => 'MyProject\Entities',
    '/path/to/files2' => 'OtherProject\Entities'
);
$driver = new \Doctrine\ORM\Mapping\Driver\SimplifiedYamlDriver($namespaces);
$driver->setGlobalBasename('global'); // global.orm.yml

21.1.1. Example

As a quick start, here is a small example document that makes use of several common elements:

# Doctrine.Tests.ORM.Mapping.User.dcm.yml
Doctrine\Tests\ORM\Mapping\User:
  type: entity
  repositoryClass: Doctrine\Tests\ORM\Mapping\UserRepository
  table: cms_users
  readOnly: true
  indexes:
    name_index:
      columns: [ name ]
  id:
    id:
      type: integer
      generator:
        strategy: AUTO
  fields:
    name:
      type: string
      length: 50
    email:
      type: string
      length: 32
      column: user_email
      unique: true
      options:
        fixed: true
        comment: User's email address
    loginCount:
      type: integer
      column: login_count
      nullable: false
      options:
        unsigned: true
        default: 0
  oneToOne:
    address:
      targetEntity: Address
      joinColumn:
        name: address_id
        referencedColumnName: id
        onDelete: CASCADE
  oneToMany:
    phonenumbers:
      targetEntity: Phonenumber
      mappedBy: user
      cascade: ["persist", "merge"]
  manyToMany:
    groups:
      targetEntity: Group
      joinTable:
        name: cms_users_groups
        joinColumns:
          user_id:
            referencedColumnName: id
        inverseJoinColumns:
          group_id:
            referencedColumnName: id
  lifecycleCallbacks:
    prePersist: [ doStuffOnPrePersist, doOtherStuffOnPrePersistToo ]
    postPersist: [ doStuffOnPostPersist ]

Be aware that class-names specified in the YAML files should be fully qualified.

21.2. Reference

21.2.1. Unique Constraints

It is possible to define unique constraints by the following declaration:

# ECommerceProduct.orm.yml
ECommerceProduct:
  type: entity
  fields:
    # definition of some fields
  uniqueConstraints:
    search_idx:
      columns: [ name, email ]
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