How to add an autocomplete field in a Symfony2 form for a collection and using Propel?

Question

I\'m using Symfony 2.1 forms with PropelBundle and I\'m trying to refactor a form that had a drop-down list of objects (to select from) to instead use a jquery autocomplete fiel

Answer 1

The solution I ultimately went for is slightly different from my previous answer. I ended up using a "text" field type instead of a "collection" field type in my "ReaderType" form, since I ended up using the Loopj Tokeninput jQuery plugin which allows for selecting multiple objects (e.g. "Favorite Book") to associate to my main object (e.g. "Reader" object) in the form. Considering that, I created a "Data Transformer" for transforming the objects' ids passed (in a comma separated list in the text field) into a Propel Object Collection. The code is shared as follows, including a sample ajax object controller.

The key part of the "ReaderType" form looks as follows:

$transformer = new BooksToIdsTransformer();
$builder->add(
    $builder->create('books', 'text', array(
        'required' => false,
    ))->addModelTransformer($transformer)
);

The "Data Transformer" file looks like this:

// src/MyVendor/MyBundle/Form/DataTransformer/BooksToIdsTransformer.php
namespace MyVendor\MyBundle\Form\DataTransformer;

use \PropelObjectCollection;
use Symfony\Component\Form\DataTransformerInterface;
use Symfony\Component\Form\Exception\UnexpectedTypeException;
use MyVendor\MyBundle\Model\BookQuery;

class BooksToIdsTransformer implements DataTransformerInterface
{
    public function transform($books)
    {
        if (null === $books) {
            return "";
        }

        if (!$books instanceof PropelObjectCollection) {
            throw new UnexpectedTypeException($books, '\PropelObjectCollection');
        }
        $idsArray = array();
        foreach ($books as $book) {
            $idsArray[] = $book->getId();
        }
        $ids = implode(",", $idsArray);
        return $ids;
    }

    public function reverseTransform($ids)
    {
        $books = new PropelObjectCollection();

        if ('' === $ids || null === $ids) {
            return $books;
        }

        if (!is_string($ids)) {
            throw new UnexpectedTypeException($ids, 'string');
        }
        $idsArray = explode(",", $ids);
        $idsArray = array_filter ($idsArray, 'is_numeric');
        foreach ($idsArray as $id) {
            $books->append(BookQuery::create()->findOneById($id));
        }
        return $books;
    }
}

The ajax controller that returns a json collection of "books" to the Tokeninput autocomplete function is as follows:

namespace MyVendor\MyBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use MyVendor\MyBundle\Model\BookQuery;


class ClassAjaxController extends Controller
{
    public function bookAction(Request $request)
    {
        $value = $request->get('q');

        $books = BookQuery::create()->findByName('%'.$value.'%');

        $json = array();
        foreach ($books as $book) {
            $json[] = array(
                'id' => $book->getId(),
                'name' => $book->getName()
            );
        }

        $response = new Response();
        $response->setContent(json_encode($json));

        return $response;
    }
}

And finally, the router in the "routing.yml" file:

ajax_book:
    pattern:  /ajax_book
    defaults: { _controller: MySiteBundle:ClassAjax:book }