Symfony 3：如何在Form中实现包含大量对象的EntityType？

Question

I have an entity City with more than 30000 objects stored. User is able to add an Address object with a relation ManyToOne to City. But during Form building, the rendering of <input> type radio or select is not appropriate for the number of objects...

I use the following implementation code (it is a snippet):

public function buildForm(FormBuilderInterface $builder, array $options)
{
  /* Pattern to get cities */
  $pattern = 'Bor%';  //I use this filter to reduce the number of objects but not sufficient

  $builder
    ->add('city', EntityType::class, array(
      'class'        => 'AppPlatformBundle:City',
      'choice_label' => 'name',
      'multiple'     => false,
      'expanded'     => true,
      'query_builder'=> function(CityRepository $repository) use($pattern) {
        return $repository->getCitiesWithPattern($pattern);
      }));
}

I think that a solution is to use a TextType where the proposals can be selected by the user when he start type anything. But I haven't idea on how implement this.

Do you have a solution on my issue please?

Thank you

Answer 1

With this steps :

1. Create a custom form type inheriting from a simple TextType
2. Use this custom form type with a javascript autocomplete plugin and an ajax call
3. Create your custom action in order to retrieve your choices for your select box (created by the plugin)
4. Use a Data Transformer in your custom form type in order to retrieve objects instead of values