Sonata Media Bundle - How to write a custom image resizer

Question

I'm using the Sonata Media Bundle and I need to code a specific behavior for the image resizer, because the default SimpleResizer and SquareResizer classes don't fit my needs.

I would like a simple image resizer that lets me resize the image exactly if I specify both the width and height parameters. I would also like that it can fallback on the simple resizer behavior if I don't specify a height parameter.

I've just searched for the docs but I wasn't able to find a solution.

Answer 1

First of all you have to create a resizer service in your bundle in order to put it in the Sonata Media Bundle configuration.

# Acme/Bundle/CoreBundle/Resources/config/services.yml

services:
    sonata.media.resizer.custom:
        class: Acme\Bundle\CoreBundle\Resizer\CustomResizer
        arguments: [@sonata.media.adapter.image.gd, 'outbound', @sonata.media.metadata.proxy]

The second service argument, in this case, must be 'outbound'. Allowed parameters are ImageInterface::THUMBNAIL_INSET and ImageInterface::THUMBNAIL_OUTBOUND.

Now the Acme\Bundle\CoreBundle\Resizer\CustomResizer code:

<?php

    namespace Acme\Bundle\CoreBundle\Resizer;

    use Imagine\Image\ImagineInterface;
    use Imagine\Image\Box;
    use Gaufrette\File;
    use Sonata\MediaBundle\Model\MediaInterface;
    use Sonata\MediaBundle\Resizer\ResizerInterface;
    use Imagine\Image\ImageInterface;
    use Imagine\Exception\InvalidArgumentException;
    use Sonata\MediaBundle\Metadata\MetadataBuilderInterface;

    class CustomResizer implements ResizerInterface
    {
        protected $adapter;
        protected $mode;
        protected $metadata;

        /**
         * @param ImagineInterface $adapter
         * @param string $mode
         */
        public function __construct(ImagineInterface $adapter, $mode, MetadataBuilderInterface $metadata)
        {
            $this->adapter = $adapter;
            $this->mode = $mode;
            $this->metadata = $metadata;
        }

        /**
         * {@inheritdoc}
         */
        public function resize(MediaInterface $media, File $in, File $out, $format, array $settings)
        {
            if (!(isset($settings['width']) && $settings['width']))
                throw new \RuntimeException(sprintf('Width parameter is missing in context "%s" for provider "%s"', $media->getContext(), $media->getProviderName()));

            $image = $this->adapter->load($in->getContent());

            $content = $image
                       ->thumbnail($this->getBox($media, $settings), $this->mode)
                       ->get($format, array('quality' => $settings['quality']));

            $out->setContent($content, $this->metadata->get($media, $out->getName()));
        }

        /**
         * {@inheritdoc}
         */
        public function getBox(MediaInterface $media, array $settings)
        {
            $size = $media->getBox();
            $hasWidth = isset($settings['width']) && $settings['width'];
            $hasHeight = isset($settings['height']) && $settings['height'];

            if (!$hasWidth && !$hasHeight)
                throw new \RuntimeException(sprintf('Width/Height parameter is missing in context "%s" for provider "%s". Please add at least one parameter.', $media->getContext(), $media->getProviderName()));

            if ($hasWidth && $hasHeight)
                return new Box($settings['width'], $settings['height']);

            if (!$hasHeight)
                $settings['height'] = intval($settings['width'] * $size->getHeight() / $size->getWidth());

            if (!$hasWidth)
                $settings['width'] = intval($settings['height'] * $size->getWidth() / $size->getHeight());

            return $this->computeBox($media, $settings);
        }

        /**
         * @throws InvalidArgumentException
         *
         * @param MediaInterface $media
         * @param array $settings
         *
         * @return Box
         */
        private function computeBox(MediaInterface $media, array $settings)
        {
            if ($this->mode !== ImageInterface::THUMBNAIL_INSET && $this->mode !== ImageInterface::THUMBNAIL_OUTBOUND)
                throw new InvalidArgumentException('Invalid mode specified');

            $size = $media->getBox();

            $ratios = [
                $settings['width'] / $size->getWidth(),
                $settings['height'] / $size->getHeight()
            ];

            if ($this->mode === ImageInterface::THUMBNAIL_INSET)
                $ratio = min($ratios);
            else
                $ratio = max($ratios);

            return $size->scale($ratio);
        }
    }

Well done. Your service is defined. You have to link it in the app/config.yml and all is done. I've included the whole sonata_media configuration in order to provide a good example, but remember you only need the last three lines.

sonata_media:
    default_context: default
    db_driver: doctrine_orm # or doctrine_mongodb, doctrine_phpcr
    contexts:
        default:  # the default context is mandatory
            providers:
                - sonata.media.provider.dailymotion
                - sonata.media.provider.youtube
                - sonata.media.provider.image
                - sonata.media.provider.file

            formats:
                small: { width: 100, height: 100, quality: 70 }
                big:   { width: 500, height: 300, quality: 70 }
            download:
                strategy: sonata.media.security.public_strategy
    cdn:
        server:
            path: /uploads/media # http://media.sonata-project.org/
    filesystem:
        local:
            directory:  %kernel.root_dir%/../web/uploads/media
            create:     true
    providers:
        image:
            resizer: sonata.media.resizer.custom # THIS IS OUR NEW RESIZER SERVICE