Chapters

13 Chapters | 1:00:24 |

01

Form Parts & Functions Reference

3:10
02

Form Rendering Functions

4:56
03

Form Variables are the Bomb

5:45
04

Pro Form Theming

5:37
05

Form Theming: Add an Error Icon

5:23
06

Complex Blocks & the parent() Function

5:32
07

Adding Form Field Help Text

2:42
08

Go Deeper: Vars, Twig merge & Form Functions

4:37
09

Form Options & Variables: Dream Team

5:15
10

Controlling Vars with finishView()

2:36
11

Form Type Extension Magic

5:31
12

Compound & Embedded Forms

3:03
13

Rendering Fields Manually

6:17

> Symfony 3 > Getting Crazy with Form Themes

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11.

Form Type Extension Magic

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The only way to make an option valid for a field is to, well, hack the core class and add it! For example, since funFact is a TextType, I could - if I were feeling crazy - open TextType, scroll down, and hack that help option into configureOptions():

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            vendor/symfony/symfony/src/Symfony/Component/Form/Extension/Core/Type/TextType.php
        
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                                                    // ... lines 1 - 16
                            
            use Symfony\Component\OptionsResolver\OptionsResolver;
        
            class TextType extends AbstractType implements DataTransformerInterface
        
            {
        
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                                                    // ... lines 21 - 35
                            
                public function configureOptions(OptionsResolver $resolver)
        
                {
        
                    $resolver->setDefaults(array(
        
                        'compound' => false,
        
                    ));
        
                }
        
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                                                    // ... lines 42 - 67
                            
            }

With a few other hacks, we could have this feature working!

Form Plugins: Type Extensions

Obviously, this is not the right path to take, and that's ok, but there is another way to add an option to a field. It's called a form type extension, and it's basic a plugin to the Symfony form field system. By leveraging a form type extension, you can modify any field in the system. You could, I don't know, add a new attribute to literally every single field on your entire site.

Let's find out how.

Creating a Form Type Extension

In your Form directory, create a new directory called TypeExtension and then a new class called HelpFormExtension:

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            src/AppBundle/Form/TypeExtension/HelpFormExtension.php
        
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                                                    // ... lines 1 - 2
                            
            namespace AppBundle\Form\TypeExtension;
        
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                                                    // ... lines 4 - 6
                            
            class HelpFormExtension extends AbstractTypeExtension
        
            {
        
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                                                    // ... lines 9 - 12
                            
            }

The goal of this class will be to to allow for a help option to be passed to any field, and to turn that help option into a help variable.

First, all form type extensions should extend AbstractTypeExtension:

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            src/AppBundle/Form/TypeExtension/HelpFormExtension.php
        
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                                                    // ... lines 1 - 2
                            
            namespace AppBundle\Form\TypeExtension;
        
            use Symfony\Component\Form\AbstractTypeExtension;
        
            class HelpFormExtension extends AbstractTypeExtension
        
            {
        
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                                                    // ... lines 9 - 12
                            
            }

Next, use the "Code"->"Generate" menu, or Command+N on a Mac, and click "Implement Methods". This abstract class requires us to have one method: getExtendedType():

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            src/AppBundle/Form/TypeExtension/HelpFormExtension.php
        
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                                                    // ... lines 1 - 2
                            
            namespace AppBundle\Form\TypeExtension;
        
            use Symfony\Component\Form\AbstractTypeExtension;
        
            class HelpFormExtension extends AbstractTypeExtension
        
            {
        
                public function getExtendedType()
        
                {
        
                    // TODO: Implement getExtendedType() method.
        
                }
        
            }

You see, when you create a form type extension, you could make it modify every field in your entire system, or just one type, like the FileType. To modify every field, return FormType::class:

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            src/AppBundle/Form/TypeExtension/HelpFormExtension.php
        
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                                                    // ... lines 1 - 5
                            
            use Symfony\Component\Form\Extension\Core\Type\FormType;
        
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                                                    // ... lines 7 - 9
                            
            class HelpFormExtension extends AbstractTypeExtension
        
            {
        
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                                                    // ... lines 12 - 16
                            
                public function getExtendedType()
        
                {
        
                    return FormType::class;
        
                }
        
            }

Because remember, FormType is the parent for all fields.

Tip

Technically, FormType is the parent type for all fields, except for buttons. But I don't like adding buttons to my form anyways!

Overriding Field Behavior

Here's the cool thing about these classes: they have all the same functions as a normal form class, like buildForm() or configureOptions(). The difference is that whatever modifications we make to this class will literally be applied to every field in the system.

For example, go back to the "Code"->"Generate" menu, click "Override Methods", then select buildView():

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            src/AppBundle/Form/TypeExtension/HelpFormExtension.php
        
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                                                    // ... lines 1 - 6
                            
            use Symfony\Component\Form\FormInterface;
        
            use Symfony\Component\Form\FormView;
        
            class HelpFormExtension extends AbstractTypeExtension
        
            {
        
                public function buildView(FormView $view, FormInterface $form, array $options)
        
                {
        
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                                                    // ... line 14
                            
                }
        
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                                                    // ... lines 16 - 20
                            
            }

When we're done setting things up, whenever any field is transformed into a FormView object, this method will be called and we will be able to add variables to anything!

Try it: add $view - which represents whatever one field is being setup - $view->vars['help'] set to TURTLES!

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            src/AppBundle/Form/TypeExtension/HelpFormExtension.php
        
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                                                    // ... lines 1 - 9
                            
            class HelpFormExtension extends AbstractTypeExtension
        
            {
        
                public function buildView(FormView $view, FormInterface $form, array $options)
        
                {
        
                    $view->vars['help'] = 'TURTLES!';
        
                }
        
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                                                    // ... lines 16 - 20
                            
            }

That's a ridiculous, and yet, fully-functional type extension.

Registering a Type Extension

To tell Symfony about this, you guys can probably guess, we need to register this as a service. In app/config/services.yml, add a new service: call it app.form.help_form_extension. Set its class to HelpFormExtension and then I'll set autowire to true... even though the class doesn't have any constructor arguments, at least not yet:

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            app/config/services.yml
        
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                                                    // ... lines 1 - 5
                            
            services:
        
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                                                    // ... lines 7 - 27
                            
                app.form.help_form_extenion:
        
                    class: AppBundle\Form\TypeExtension\HelpFormExtension
        
                    autowire: true
        
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                                                    // ... lines 31 - 33

Then, to actually tell Symfony: "Hey! This is a form type extension!", add a tag, set to form.type_extension. Also give this an extended_type option. This needs to match whatever you're returning from getExtendedType(). FormType::class returns the long string in the use statement, so copy that, and paste it into your service:

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            app/config/services.yml
        
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                                                    // ... lines 1 - 5
                            
            services:
        
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                                                    // ... lines 7 - 27
                            
                app.form.help_form_extenion:
        
                    class: AppBundle\Form\TypeExtension\HelpFormExtension
        
                    autowire: true
        
                    tags:
        
                        - { name: form.type_extension, extended_type: Symfony\Component\Form\Extension\Core\Type\FormType }

That's it team! Temporarily remove the help option from GenusFormType, ya know, so the page doesn't explode. Then, refresh! OMG, everyone is screaming about TURTLES! Well, everyone except for the isPublished field, because we're overriding that help variable at the last possible second: from inside the template.

Using the Option to Fuel the help Variable

Finally, uncomment the help option. So, how can we make this a valid option? Go back to HelpFormExtension, use the "Code"->"Generate" menu one last time, click "Override Methods", and select configureOptions():

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            src/AppBundle/Form/TypeExtension/HelpFormExtension.php
        
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                                                    // ... lines 1 - 8
                            
            use Symfony\Component\OptionsResolver\OptionsResolver;
        
            class HelpFormExtension extends AbstractTypeExtension
        
            {
        
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                                                    // ... lines 13 - 19
                            
                public function configureOptions(OptionsResolver $resolver)
        
                {
        
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                                                    // ... line 22
                            
                }
        
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                                                    // ... lines 24 - 28
                            
            }

Our job here is so simple: $resolver->setDefault('help', null):

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            src/AppBundle/Form/TypeExtension/HelpFormExtension.php
        
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                                                    // ... lines 1 - 10
                            
            class HelpFormExtension extends AbstractTypeExtension
        
            {
        
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                                                    // ... lines 13 - 19
                            
                public function configureOptions(OptionsResolver $resolver)
        
                {
        
                    $resolver->setDefault('help', null);
        
                }
        
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                                                    // ... lines 24 - 28
                            
            }

Just by doing that, you are now allowed to have a help option on any field. It also means that when buildView() is called, the $options array will have a key called help. All we need to say is if $options['help'], then set the help variable to $options['help']:

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            src/AppBundle/Form/TypeExtension/HelpFormExtension.php
        
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                                                    // ... lines 1 - 10
                            
            class HelpFormExtension extends AbstractTypeExtension
        
            {
        
                public function buildView(FormView $view, FormInterface $form, array $options)
        
                {
        
                    if ($options['help']) {
        
                        $view->vars['help'] = $options['help'];
        
                    }
        
                }
        
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                                                    // ... lines 19 - 28
                            
            }

And that takes care of it. Try this puppy out.

And consider yourself very, very dangerous.

5 Comments

Sort By

maraloon 6 years ago

https://knpuniversity.com/s...

I think it will be good to remind about Symfony3.3-like adding service:

AppBundle\Form\TypeExtension\HelpFormExtension:
tags:
- { name: form.type_extension, extended_type: Symfony\Component\Form\Extension\Core\Type\FormType }

| Reply |

weaverryan SFCASTS maraloon 6 years ago edited

maraloon We'll be releasing a whole new suite of Symfony 4 videos soon :). The service name change for Symfony 3.3 was a bit tough - we added a bunch of notes in our older tutorials to make people aware. But mostly, this will be improved with fresh tutorials!

| Reply |

Josk 6 years ago

Hi, I get this error at the end:
Type error: Argument 1 passed to Symfony\Component\OptionsResolver\OptionsResolver::setDefaults() must be of the type array, string given, called in C:\Users\John\Documents\Siti\aqua_note\src\AppBundle\Form\TypeExtension\HelpFormExtension.php on line 22
I think It shouldn't be an array because it's a value and its option, what am I doing wrong? Below my code:
namespace AppBundle\Form\TypeExtension;

use Symfony\Component\Form\AbstractTypeExtension;
use Symfony\Component\Form\Extension\Core\Type\FormType;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\Form\FormView;
use Symfony\Component\OptionsResolver\OptionsResolver;

class HelpFormExtension extends AbstractTypeExtension
{
public function buildView(FormView $view, FormInterface $form, array $options)
{
if ($options['help']) {
$view->vars['help'] = $options['help'];
}
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults('help', null);
}
public function getExtendedType()
{
return FormType::class;
}
}

Thanks in advance

| Reply |

Josk Josk 6 years ago

Solved, I made a stupid typo mistake (setDefaults instead of setDefault) :(

| Reply |

Victor SFCASTS Josk 6 years ago

Hey Josh,

Ah, those methods do the same but in a different way, very easy to miss "s" at the end :)
I'm glad you found the problem so quick.

Cheers!

| Reply |

This tutorial is built on Symfony 3 but form theming hasn't changed much in Symfony 4 and Symfony 5. Other than some path differences - this tutorial should work fine.

Symfony 3

What PHP libraries does this tutorial use?

// composer.json
{
    "require": {
        "php": "^7.1.3",
        "symfony/symfony": "3.4.*", // v3.4.49
        "doctrine/orm": "^2.5", // 2.7.5
        "doctrine/doctrine-bundle": "^1.6", // 1.12.13
        "doctrine/doctrine-cache-bundle": "^1.2", // 1.4.0
        "symfony/swiftmailer-bundle": "^2.3", // v2.6.7
        "symfony/monolog-bundle": "^2.8", // v2.12.1
        "symfony/polyfill-apcu": "^1.0", // v1.23.0
        "sensio/distribution-bundle": "^5.0", // v5.0.25
        "sensio/framework-extra-bundle": "^3.0.2", // v3.0.29
        "incenteev/composer-parameter-handler": "^2.0", // v2.1.4
        "composer/package-versions-deprecated": "^1.11", // 1.11.99.4
        "knplabs/knp-markdown-bundle": "^1.4", // 1.9.0
        "doctrine/doctrine-migrations-bundle": "^1.1", // v1.3.2
        "stof/doctrine-extensions-bundle": "^1.2" // v1.3.0
    },
    "require-dev": {
        "sensio/generator-bundle": "^3.0", // v3.1.7
        "symfony/phpunit-bridge": "^3.0", // v3.4.47
        "nelmio/alice": "^2.1", // v2.3.6
        "doctrine/doctrine-fixtures-bundle": "^2.3" // v2.4.1
    }
}

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Form Type Extension Magic

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Form Plugins: Type Extensions

Creating a Form Type Extension

Overriding Field Behavior

Registering a Type Extension

Using the Option to Fuel the help Variable

5 Comments

Delete comment?

What PHP libraries does this tutorial use?

Show Lines	// ... lines 1 - 16
	use Symfony\Component\OptionsResolver\OptionsResolver;

	class TextType extends AbstractType implements DataTransformerInterface
	{
Show Lines	// ... lines 21 - 35
	public function configureOptions(OptionsResolver $resolver)
	{
	$resolver->setDefaults(array(
	'compound' => false,
	));
	}
Show Lines	// ... lines 42 - 67
	}

Show Lines	// ... lines 1 - 2
	namespace AppBundle\Form\TypeExtension;
Show Lines	// ... lines 4 - 6
	class HelpFormExtension extends AbstractTypeExtension
	{
Show Lines	// ... lines 9 - 12
	}

Show Lines	// ... lines 1 - 5
	use Symfony\Component\Form\Extension\Core\Type\FormType;
Show Lines	// ... lines 7 - 9
	class HelpFormExtension extends AbstractTypeExtension
	{
Show Lines	// ... lines 12 - 16
	public function getExtendedType()
	{
	return FormType::class;
	}
	}

Show Lines	// ... lines 1 - 6
	use Symfony\Component\Form\FormInterface;
	use Symfony\Component\Form\FormView;

	class HelpFormExtension extends AbstractTypeExtension
	{
	public function buildView(FormView $view, FormInterface $form, array $options)
	{
Show Lines	// ... line 14
	}
Show Lines	// ... lines 16 - 20
	}

Show Lines	// ... lines 1 - 9
	class HelpFormExtension extends AbstractTypeExtension
	{
	public function buildView(FormView $view, FormInterface $form, array $options)
	{
	$view->vars['help'] = 'TURTLES!';
	}
Show Lines	// ... lines 16 - 20
	}

Show Lines	// ... lines 1 - 5
	services:
Show Lines	// ... lines 7 - 27
	app.form.help_form_extenion:
	class: AppBundle\Form\TypeExtension\HelpFormExtension
	autowire: true
Show Lines	// ... lines 31 - 33

Show Lines	// ... lines 1 - 8
	use Symfony\Component\OptionsResolver\OptionsResolver;

	class HelpFormExtension extends AbstractTypeExtension
	{
Show Lines	// ... lines 13 - 19
	public function configureOptions(OptionsResolver $resolver)
	{
Show Lines	// ... line 22
	}
Show Lines	// ... lines 24 - 28
	}

Show Lines	// ... lines 1 - 10
	class HelpFormExtension extends AbstractTypeExtension
	{
Show Lines	// ... lines 13 - 19
	public function configureOptions(OptionsResolver $resolver)
	{
	$resolver->setDefault('help', null);
	}
Show Lines	// ... lines 24 - 28
	}