Webservice/Form/ChoiceList/Loader/ClientChoiceLoader.php

<?php

namespace WebserviceBundle\Form\ChoiceList\Loader;

use Symfony\Component\Form\ChoiceList\ArrayChoiceList;
use Symfony\Component\Form\ChoiceList\Loader\ChoiceLoaderInterface;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormEvent;
use Symfony\Component\Form\FormEvents;

class ClientChoiceLoader implements ChoiceLoaderInterface
{
    
    /**
     * @var Webservice
     */
    protected $webservice;

    // Currently selected choices
    protected $selected = [];

    
    /**
     * @param Webservice $webservice
     */
    public function __construct($webservice)
    {
        $this->webservice = $webservice;
    }
    
    /**
     * @param FormBuilderInterface $builder
     */
    public function setBuilder(FormBuilderInterface $builder)
    {
        if (is_object($builder) && ($builder instanceof FormBuilderInterface)) {
            $builder->addEventListener(
                FormEvents::POST_SET_DATA, [$this, 'onFormPostSetData']
            );

            $builder->addEventListener(
                FormEvents::POST_SUBMIT, [$this, 'onFormPostSetData']
            );
        }
    }

    /**
     * Form submit event callback
     * Here we get notified about the submitted choices.
     * Remember them so we can add them in loadChoiceList().
     */
    public function onFormPostSetData(FormEvent $event)
    {
        $this->selected = [];

        $formdata = $event->getData();

        if (!is_object($formdata)) {
            return;
        }

        if ($formdata->getClientId()) {
            $this->selected = array($formdata->getClientId());
        }
    }

    /**
     * Choices to be displayed in the SELECT element.
     * It's okay to not return all available choices, but the
     * selected/submitted choices (model values) must be
     * included.
     * Required by ChoiceLoaderInterface.
     */
    public function loadChoiceList($value = null)
    {
        $choices = $this->getChoicesList(false);

        $missing_choices = array_flip($this->selected);

        foreach ($choices as $label => $id) {
            if (isset($missing_choices[$id])) {
                unset($missing_choices[$id]);
            }
        }

        // Now add selected choices if they're missing
        foreach (array_keys($missing_choices) as $id) {
            $label = $this->getChoiceLabel($id);

            if (strlen($label) === 0) {
                continue;
            }

            $choices[$label] = $id;
        }
        
        return new ArrayChoiceList($choices);
    }

    /**
     * Validate submitted choices, and turn them from strings
     * (HTML option values) into other datatypes if needed
     * (not needed here since our choices are strings).
     * We're also using this place for creating new choices
     * from new values typed into the autocomplete field.
     * Required by ChoiceLoaderInterface.
     */
    public function loadChoicesForValues(array $values, $value = null)
    {
        $result = [];
        foreach ($values as $id) {
            if ($this->choiceExists($id)) {
                $result[] = $id;
            }
        }

        return $result;
    }

    /**
     * Turn choices from other datatypes into strings (HTML option
     * values) if needed - we can simply return the choices as 
     * they're strings already.
     * Required by ChoiceLoaderInterface.
     */
    public function loadValuesForChoices(array $choices, $value = null)
    {
        $result = [];
        foreach ($choices as $id) {
            if ($this->choiceExists($id)) {
                $result[] = $id;
            }
        }

        return $result;
    }

    /**
     * Get first n choices
     */
    public function getChoicesList($filter)
    {
        $params = array();
        if ($filter !== false) {
            $params['name'] = $filter;
        }
        $choices = $this->webservice->getChoices('client', $params);

        $result = [];
        $cnt = 0;
        $limit = 10;
        $filter = mb_strtolower($filter);
        $filter_len = mb_strlen($filter);

        foreach ($choices as $label => $id) {
            if ($filter_len > 0) {
                if (mb_substr(mb_strtolower($label), 0, $filter_len) !== $filter) {
                    continue;
                }
            }

            $result[$label] = $id;

            if (++$cnt >= $limit) {
                break;
            }
        }

        return $result;
    }

    /**
     * Validate whether a choice exists
     */
    protected function choiceExists($id)
    {
        $label = array_search($id, $this->initChoices());

        return $label === false ? false : true;
    }

    /**
     * Get choice label
     */
    protected function getChoiceLabel($id)
    {
        $label = array_search($id, $this->initChoices());

        return $label === false ? false : $label;
    }

    /**
     * @return array
     */
    protected function initChoices()
    {
        return $this->webservice->getChoices('client');
    }

}