symfony form basics - oromeetup #3 cherkassy

Presentation title here

Symfony Form

“Make simple cases simple, make complex cases possible”

- Bernhard Schussek

presented by Andreii Yatsenko


About me

● Я Андрюха● PHP Developer at Oro Inc.● Live in Kyiv● Studied at GeekHub ~3 years ago● 6 years with PHP


Agenda

● Form Flow● Form EventListeners● Form Extensions● Data Transformers● Form Tests

● Bad and Good Practices● Almost W/O code samples


Form flow

● create form● set data to form● handle request● Profit! do something with updated data

○ E.g. persist data to DB


How to create form?At first ● you need to create formFactory● or if you are using Symfony just get it from

ServiceContainer

$formFactory = $container->get(“form.factory”);


How to create form?

● 1) using FormBuilder in Controller :($formFactory->createFormBuilder()

->add(‘firstName”)->add(“lastName”)->add(“email”);


How to create form?

● 2) using FormType


How to create form?

● If you in Controller$this->createForm($formType)// or$this->createFormBuilder()

->add(“name”, “text”)->getForm();


How to set form data?


Always set form data at form creation!

$data = new User();$formFactory

->createForm($formType, $data, $options);// or$formFactory->createFormBuilder($data);


Try to not setData after form creation

Because● All form events will be triggered twice :(

$form = $formFactory->createForm($formType);

$form->setData($data);


Always use objects instead of arrays!


If you don’t have object - you just not created it yet!

● Create DTO


Why objects, I like kittens arrays?


Because of ValidationValidation


How to Validate Form

● Do not validate form!● Validate data

○ yaml, xml, annotation drivers for constrants

● But what if my form doesn’t submit the data? ○ like “Apply terms checkbox”

● Make field mapped = false and validate form


$formFactory->createForm($formType, $data, $options);

Form options (configuration)



● Form options is a form configuration. And it’s a data too, data that needed for building and submitting the form, but it’s not the Form Data (Usually don’t need to be updated from user input)



● Buy the way Form Data is an option too. You can just set $options[‘data’], and form factory internally use it too. It’s have higher priority than $data (second param) in

$formFactory->createForm($type, $data, $options)


Next

Some form internals


How form saves your memory

In Symfony2 all form fields are forms too, and can be reused.

E.x. ● TextFormType● CategoryFormType● ProductFormType● etc.



Form composed from ● Form (form builder template etc.) and● FormConfig (options with data)

● Form and FormConfig are different objects.



When you reuse Form, e.x. if you create form with 20 text fields, only ONE TextForm will be created.



● But for different fields you have different data, and usually different options, they are so called FormConfig and will be created for each fields, so in our example you will have 20 FormConfig objects


How to create form, that depends on data?● Use dependency injections:inject data to FormType container

E.x. new FormType($someData);


• How to create form, that depends on data?● Use dependency injections:inject data to FormType container

E.x. new FormType($someData);


Never inject dinamic objects to FormType!


Never inject dinamic objects to FormType!

Because you will change FormType, not the FormConfig, so all forms on page will be configured the same.


The right way :)

● Inject to container static objects E.x. Doctine, not concrete Entities


If I don’t have static object? :(

● Use custom form options

$formFactory->createFrom($type, $data, $options);

At first you need to configure them in FormType::configureOptions()


But wait, Where to place dinamic business logic, if I can’t place it in FormType?

:(


But wait, Where to place dinamic business logic, if I can’t place it in FormType?

In EventListeners! :)


Form Events

● PRE_SET_DATA● POST_SET_DATA

● PRE_SUBMIT● SUBMIT● POST_SUBMIT


How to subscribe to form events?

1) Create:● EventListener - any callable● EventSubscriber - separate class

implementedSymfony\Component\EventDispatcher\EventSubscriberInterface

2) Add them to FormBuilder

$builder->addEventListener(“PRE_SUBMIT”, $listener);

$builder->addEventSubscriber($subscriber)


You can even change the form in EventListeners● add or remove form fields

http://symfony.com/doc/current/components/form/form_events.html


You can even change the form in EventListeners● but in Symfony you can’t change or

replace form field

In OroPlatform we have FormUtils that solve this problemhttps://github.com/orocrm/platform/blob/936c1bfcff34c2381a31fa40726d518d3f6ab0b8/src/Oro/Bundle/FormBundle/Utils/FormUtils.php

https://github.com/orocrm/platform/blob/936c1bfcff34c2381a31fa40726d518d3f6ab0b8/src/Oro/Bundle/FormBundle/Utils/FormUtils.php






But you can’t register event listener like in symfony or doctrine EventDispatcher, from another bundle


How to solve this?


How to solve this?

FormTypeExtensions


FormTypeExtensions● Like form types but have getExtendedType()

method● extends Symfony\Component\Form\AbstractTypeExtension

● Registered in DI with tag form.type_extension


How form works with data internally?



E.x. DateTimeFormType● You set to form timestamp

● User will see human formatted string



E.x. DateTimeFormType● You set to form timestamp● In EventListeners you work with DateTime ● User will see human formatted string



E.x.● Controller - timestamp● Form - DateTime ● User - formatted string



E.x.● Model Data - timestamp● Normalized Data - DateTime ● View Data - formatted string


Data Transformers● Model Transformer● View Transformer

implement Symfony\Component\Form\DataTransformerInterface

2 methods:● transform($data)● reverseTransform($data)


Data Transformers

Register at $builder

$builder->get('date') ->addModelTransformer($transformer);


Data Transformers

● Should only transform data from one format to another, but never change the data.

● If you want to change data use EventListeners


Debugging Forms


How to test forms

Unit Test$builder = $this->createMock(“FormBuilder”);$builder->expects($this->at(1))->method(“add”)->withArguments(“username”, “text”)//...


How to test forms

● Write Integrational tests \Symfony\Component\Form\Test\FormIntegrationTestCaseE.x.https://github.com/laboro/b2b/blob/9d18a036099357b04d41116ca2dfcaa57a59163c/src/OroB2B/Bundle/AccountBundle/Tests/Unit/Form/Extension/CategoryFormExtensionTest.php#L34-L34

https://github.com/laboro/b2b/blob/9d18a036099357b04d41116ca2dfcaa57a59163c/src/OroB2B/Bundle/AccountBundle/Tests/Unit/Form/Extension/CategoryFormExtensionTest.php#L34-L34






Agenda

● Form Flow● Form EventListeners● Form Extensions● Data Transformers● Form Tests


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symfony form basics - oromeetup #3 cherkassy

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