使用 'choice_list' 将表单更新为 Symfony >= 2.8

Question

我想将表单 class 更新到 Symfony2.8（后来更新到 Symfony3）。现在除了一个不再支持的属性 choice_list 外，表单已转换。而且我不知道该怎么做。

我有以下也定义为服务的表单类型：

class ExampleType extends AbstractType
{

    /** @var Delegate */
    private $delegate;

    public function __construct(Delegate $delegate)
    {
        $this->delegate = $delegate;
    }

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('list', ChoiceType::class, array(
            'choice_list' => new ExampleChoiceList($this->delegate),
            'required'=>false)
        );
    }

    public function configureOptions(OptionsResolver $resolver)
    {
            $resolver->setDefaults(array(
                'data_class' => 'ExampleClass',
            ));
    }
}

我有以下 class 选择列表：

class ExampleChoiceList extends LazyChoiceList
{

    /** @var Delegate  */
    private $delegate;

    public function __construct(Delegate $delegate)
    {
        $this->delegate = $delegate;
    }


    /**
     * Loads the choice list
     * Should be implemented by child classes.
     *
     * @return ChoiceListInterface The loaded choice list
     */
    protected function loadChoiceList()
    {
        $persons = $this->delegate->getAllPersonsFromDatabase();
        $personsList = array();
        foreach ($persons as $person) {
            $id = $person->getId();
            $personsList[$id] = (string) $person->getLastname().', '.$person->getFirstname();
        }
        return new ArrayChoiceList($personsList);
    }


}

class ExampleChoiceList 生成我想要的选择列表，直到现在它都有效。但是属性 choice_list 不再被支持，我的问题是 "how do I get this converted without too much work?"。我读到我应该使用简单的 choice 但是我如何在 Symfony 2.8 中得到我想要的（数据库中的特定标签）。我希望有人能帮助我。

Answer 1

是的，'choice_list' 在 SYmfony 2.8 中已被弃用，但您可以改用 'choices'，它也接受数组。来自 documentation:

The choices option is an array, where the array key is the item's label and the array value is the item's value.

你一定要注意，在Symfony 3.0中，keys和values是颠倒的，而在Symfony 2.8中，推荐的方式是使用新的倒序，并指定'choices_as_values' => true。

因此，在表单中输入：

$builder->add('list', ChoiceType::class, array(
               'choices' => new ExampleChoiceList($this->delegate),
               'choices_as_values' => true,
               'required'=>false));

在 ExampleChoiceList 中：

protected function loadChoiceList()
    {
        $persons = $this->delegate->getAllPersonsFromDatabase();
        $personsList = array();
        foreach ($persons as $person) {
            $id = $person->getId();
            $personsList[(string) $person->getLastname().', '.$person->getFirstname()] = $id; // <== here
        }
        return new ArrayChoiceList($personsList);
    }

更新：

好的，所以我建议您根本不要使用 ChoiceType，而是使用 EntityType，因为您似乎要从数据库中获取所有 "Persons"。要将 "Last Name, First Name" 显示为标签，请使用 'choice_label' 选项。假设您的实体名为 'Person':

$builder->add('list', EntityType::class, array(
    'class' => 'AppBundle:Person',
    'choice_label' => function ($person) {
        return $person->getLastName() . ', ' . $person->getFirstName();
    }
));

Answer 2

使用 ChoiceListInterface 你就快到了。

我建议您将 ExampleChoiceList 改为实现 Symfony\Component\Form\ChoiceList\Loader\ChoiceLoaderInterface，它需要您实现 3 个方法：

<?php
// src/AppBundle/Form/ChoiceList/Loader/ExampleChoiceLoader.php

namespace AppBundle\Form\ChoiceList\Loader;

use Acme\SomeBundle\Delegate;
use Symfony\Component\Form\ArrayChoiceList;
use Symfony\Component\Form\Loader\ChoiceLoaderInterface;

class ExampleChoiceLoader implements ChoiceLoaderInterface
{
    /** $var ArrayChoiceList */
    private $choiceList;

    /** @var Delegate  */
    private $delegate;

    public function __construct(Delegate $delegate)
    {
        $this->delegate = $delegate;
    }

    /**
     * Loads the choice list
     * 
     * $value is a callable set by "choice_name" option
     *
     * @return ArrayChoiceList The loaded choice list
     */
    public function loadChoiceList($value = null)
    {
        if (null !== $this->choiceList) {
            return $this->choiceList;
        }

        $persons = $this->delegate->getAllPersonsFromDatabase();
        $personsList = array();
        foreach ($persons as $person) {
            $label = (string) $person->getLastname().', '.$person->getFirstname();
            $personsList[$label] = (string) $person->getId();
            // So $label will be displayed and the id will be used as data
            // "value" will be ids as strings and used for post
            // this is just a suggestion though
        }

        return $this->choiceList = new ArrayChoiceList($personsList);
    }

    /**
     * {@inheritdoc}
     *
     * $choices are entities or the underlying data you use in the field
     */
    public function loadValuesForChoices(array $choices, $value = null)
    {
        // optimize when no data is preset
        if (empty($choices)) {
            return array();
        }

        $values = array();
        foreach ($choices as $person) {
            $values[] = (string) $person->getId();
        }

        return $values;
    }

    /**
     * {@inheritdoc}
     * 
     * $values are the submitted string ids
     *
     */
    public function loadChoicesForValues(array $values, $value)
    {
        // optimize when nothing is submitted
        if (empty($values)) {
            return array();
        }

        // get the entities from ids and return whatever data you need.
        // e.g return $this->delegate->getPersonsByIds($values);
    }
}

将加载程序和类型都注册为服务以便注入：

# app/config/services.yml

services:
    # ...
    app.delegate:
        class: Acme\SomeBundle\Delegate

    app.form.choice_loader.example:
        class: AppBundle\Form\ChoiceList\Loader\ExampleChoiceLoader
        arguments: ["@app.delegate"]

    app.form.type.example:
        class: AppBundle\Form\Type\ExampleType
        arguments: ["@app.form.choice_loader.example"]

然后更改表单类型以使用加载程序：

<?php
// src/AppBundle/Form/Type/ExampleType.php

namespace AppBundle\Form\Type;

use AppBundle\Form\ChoiceList\Loader\ExampleChoiceLoader;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;

class ExampleType extends AbstractType
{
    /** @var ExampleChoiceLoader */
    private $loader;

    public function __construct(ExampleChoiceLoader $loader)
    {
        $this->loader = $loader;
    }

    public function buildForm(FormBuilderInterface $builder, array $options = array())
    {
        $builder->add('list', ChoiceType::class, array(
            'choice_loader' => $this->loader,
            'required' => false,
        ));
    }

    // ...

}

使用 'choice_list' 将表单更新为 Symfony >= 2.8

Update Form with 'choice_list' to Symfony >= 2.8

php

symfony-forms

symfony