Controlling the loading order

When we want to create a new fixture that depends on other fixtures, we will need to make sure that it is loaded after all its dependencies. To do that, we simply need to add an order property to the class and make its value higher than that of all its dependencies.

We will also need to link the entity to its dependencies (foreign keys) in the YAML file. We do that by setting the value of the foreign key to be the key of the entity it depends on. Take the following example, in which we add a Group entity...:

# src/Acme/HelloBundle/DataFixtures/ORM/Data/Group.yml

options:
  add_reference: true
data:
  admin:
    group_name: admin

<?php
// src/Acme/HelloBundle/DataFixtures/ORM/LoadGroup.php

namespace Acme\HelloBundle\DataFixtures\ORM;

class LoadGroup extends AcmeHelloOrmFixture
{
    protected $name = 'Group';
}

... and a UserGroup entity to assign a User to a Group:

# src/Acme/HelloBundle/DataFixtures/ORM/Data/userGroup.yml

options:
  foreign_keys:
    - user
    - group
data:
  -
    user: User-admin
    group: Group-admin

<?php
// src/Acme/HelloBundle/DataFixtures/ORM/LoadUserGroup.php

namespace Acme\HelloBundle\DataFixtures\ORM;

class LoadUserGroup extends AcmeHelloOrmFixture
{
    protected $name = 'UserGroup';
    protected $order = 200;
}

Notice that we referred to the admin user by making user have the value User-admin, in which the first part is the entity it refers to and the second part was the key for the admin user as defined in its YAML file (same applies for group). Also notice that the order is set to 200 to make sure User and Group are already loaded when we process UserGroup.

The loader knows that those values are foreign keys because we explicitly listed them using the foreign_keys option. Any fields that start with fk_ (case insensitive) are automatically inferred to be foreign keys, so they don’t need to be included in the list. The references exist because we added the option add_reference: true to our User.yml and Group.yml files.

We have just gone through examples that required the use of options, so let’s jump straight into that topic and describe all available options.