Symfony
sponsored by SensioLabs
Menu
  • About
  • Documentation
  • Screencasts
  • Cloud
  • Certification
  • Community
  • Businesses
  • News
  • Download
  1. Home
  2. Documentation
  3. Cookbook
  4. Form
  5. How to Configure empty Data for a Form Class
  • Documentation
  • Book
  • Reference
  • Bundles
  • Cloud
Search by Algolia

Table of Contents

  • Option 1: Instantiate a new Class
  • Option 2: Provide a Closure

How to Configure empty Data for a Form Class

Edit this page

Warning: You are browsing the documentation for Symfony 2.4, which is no longer maintained.

Read the updated version of this page for Symfony 6.2 (the current stable version).

How to Configure empty Data for a Form Class

The empty_data option allows you to specify an empty data set for your form class. This empty data set would be used if you submit your form, but haven't called setData() on your form or passed in data when you created your form. For example:

1
2
3
4
5
6
7
8
9
10
public function indexAction()
{
    $blog = ...;

    // $blog is passed in as the data, so the empty_data option is not needed
    $form = $this->createForm(new BlogType(), $blog);

    // no data is passed in, so empty_data is used to get the "starting data"
    $form = $this->createForm(new BlogType());
}

By default, empty_data is set to null. Or, if you have specified a data_class option for your form class, it will default to a new instance of that class. That instance will be created by calling the constructor with no arguments.

If you want to override this default behavior, there are two ways to do this.

Option 1: Instantiate a new Class

One reason you might use this option is if you want to use a constructor that takes arguments. Remember, the default data_class option calls that constructor with no arguments:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
// src/Acme/DemoBundle/Form/Type/BlogType.php

// ...
use Symfony\Component\Form\AbstractType;
use Acme\DemoBundle\Entity\Blog;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;

class BlogType extends AbstractType
{
    private $someDependency;

    public function __construct($someDependency)
    {
        $this->someDependency = $someDependency;
    }
    // ...

    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setDefaults(array(
            'empty_data' => new Blog($this->someDependency),
        ));
    }
}

You can instantiate your class however you want. In this example, we pass some dependency into the BlogType when we instantiate it, then use that to instantiate the Blog class. The point is, you can set empty_data to the exact "new" object that you want to use.

Option 2: Provide a Closure

Using a closure is the preferred method, since it will only create the object if it is needed.

The closure must accept a FormInterface instance as the first argument:

1
2
3
4
5
6
7
8
9
10
11
12
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
use Symfony\Component\Form\FormInterface;
// ...

public function setDefaultOptions(OptionsResolverInterface $resolver)
{
    $resolver->setDefaults(array(
        'empty_data' => function (FormInterface $form) {
            return new Blog($form->get('title')->getData());
        },
    ));
}
This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.
We stand with Ukraine.
Version:
Code consumes server resources. Blackfire tells you how

Code consumes server resources. Blackfire tells you how

Peruse our complete Symfony & PHP solutions catalog for your web development needs.

Peruse our complete Symfony & PHP solutions catalog for your web development needs.

↓ Our footer now uses the colors of the Ukrainian flag because Symfony stands with the people of Ukraine.

Avatar of Kim Wüstkamp, a Symfony contributor

Thanks Kim Wüstkamp (@kimwuestkamp) for being a Symfony contributor

2 commits • 43 lines changed

View all contributors that help us make Symfony

Become a Symfony contributor

Be an active part of the community and contribute ideas, code and bug fixes. Both experts and newcomers are welcome.

Learn how to contribute

Symfony™ is a trademark of Symfony SAS. All rights reserved.

  • What is Symfony?
    • Symfony at a Glance
    • Symfony Components
    • Case Studies
    • Symfony Releases
    • Security Policy
    • Logo & Screenshots
    • Trademark & Licenses
    • symfony1 Legacy
  • Learn Symfony
    • Symfony Docs
    • Symfony Book
    • Reference
    • Bundles
    • Best Practices
    • Training
    • eLearning Platform
    • Certification
  • Screencasts
    • Learn Symfony
    • Learn PHP
    • Learn JavaScript
    • Learn Drupal
    • Learn RESTful APIs
  • Community
    • SymfonyConnect
    • Support
    • How to be Involved
    • Code of Conduct
    • Events & Meetups
    • Projects using Symfony
    • Downloads Stats
    • Contributors
    • Backers
  • Blog
    • Events & Meetups
    • A week of symfony
    • Case studies
    • Cloud
    • Community
    • Conferences
    • Diversity
    • Documentation
    • Living on the edge
    • Releases
    • Security Advisories
    • SymfonyInsight
    • Twig
    • SensioLabs
  • Services
    • SensioLabs services
    • Train developers
    • Manage your project quality
    • Improve your project performance
    • Host Symfony projects
    Deployed on
Follow Symfony
Search by Algolia