ParameterProvider.php

<?php

namespace eZ\Publish\Core\MVC\Symfony\FieldType\Relation;

use eZ\Publish\API\Repository\ContentService;
use eZ\Publish\API\Repository\Exceptions\NotFoundException;
use eZ\Publish\API\Repository\Exceptions\UnauthorizedException;
use eZ\Publish\API\Repository\Values\Content\Field;
use eZ\Publish\Core\MVC\Symfony\FieldType\View\ParameterProviderInterface;

class ParameterProvider implements ParameterProviderInterface
{
    /** @var \eZ\Publish\API\Repository\ContentService */
    private $contentService;

    /**
     * @param \eZ\Publish\API\Repository\ContentService $contentService
     */
    public function __construct(ContentService $contentService)
    {
        $this->contentService = $contentService;
    }

    /**
     * Returns a hash of parameters to inject to the associated fieldtype's view template.
     * Returned parameters will only be available for associated field type.
     *
     * Key is the parameter name (the variable name exposed in the template, in the 'parameters' array).
     * Value is the parameter's value.
     *
     * @param \eZ\Publish\API\Repository\Values\Content\Field $field The field parameters are provided for.
     *
     * @return array
     */
    public function getViewParameters(Field $field)
    {
        try {
            $contentInfo = $this->contentService->loadContentInfo($field->value->destinationContentId);

            return [
                'available' => !$contentInfo->isTrashed(),
            ];
        } catch (NotFoundException $exception) {
            return ['available' => false];
        } catch (UnauthorizedException $exception) {
            return ['available' => false];
        }
    }
}