/**
* Returns a thumbnail of the given asset
*
* If the maximum width / height is not specified or exceeds the original asset's dimensions, the width / height of
* the original asset is used.
*
* @param AssetInterface $asset The asset to render a thumbnail for
* @param ThumbnailConfiguration $configuration
* @return ImageInterface
* @throws \Exception
*/
public function getThumbnail(AssetInterface $asset, ThumbnailConfiguration $configuration)
{
// Calculates the dimensions of the thumbnail to be generated and returns the thumbnail image if the new
// dimensions differ from the specified image dimensions, otherwise the original image is returned.
if ($asset instanceof ImageInterface) {
if ($asset->getWidth() === null && $asset->getHeight() === null) {
return $asset;
}
$maximumWidth = $configuration->getMaximumWidth() > $asset->getWidth() ? $asset->getWidth() : $configuration->getMaximumWidth();
$maximumHeight = $configuration->getMaximumHeight() > $asset->getHeight() ? $asset->getHeight() : $configuration->getMaximumHeight();
if ($configuration->isUpScalingAllowed() === false && $maximumWidth === $asset->getWidth() && $maximumHeight === $asset->getHeight()) {
return $asset;
}
}
$assetIdentifier = $this->persistenceManager->getIdentifierByObject($asset);
$configurationHash = $configuration->getHash();
if (!isset($this->thumbnailCache[$assetIdentifier])) {
$this->thumbnailCache[$assetIdentifier] = [];
}
if (isset($this->thumbnailCache[$assetIdentifier][$configurationHash])) {
$thumbnail = $this->thumbnailCache[$assetIdentifier][$configurationHash];
} else {
$thumbnail = $this->thumbnailRepository->findOneByAssetAndThumbnailConfiguration($asset, $configuration);
$this->thumbnailCache[$assetIdentifier][$configurationHash] = $thumbnail;
}
$async = $configuration->isAsync();
if ($thumbnail === null) {
try {
$thumbnail = new Thumbnail($asset, $configuration, $async);
$this->emitThumbnailCreated($thumbnail);
// If the thumbnail strategy failed to generate a valid thumbnail
if ($async === false && $thumbnail->getResource() === null && $thumbnail->getStaticResource() === null) {
$this->thumbnailRepository->remove($thumbnail);
return null;
}
if (!$this->persistenceManager->isNewObject($asset)) {
$this->thumbnailRepository->add($thumbnail);
}
$asset->addThumbnail($thumbnail);
// Allow thumbnails to be persisted even if this is a "safe" HTTP request:
$this->persistenceManager->whiteListObject($thumbnail);
$this->thumbnailCache[$assetIdentifier][$configurationHash] = $thumbnail;
} catch (NoThumbnailAvailableException $exception) {
$this->systemLogger->logException($exception);
return null;
}
$this->persistenceManager->whiteListObject($thumbnail);
$this->thumbnailCache[$assetIdentifier][$configurationHash] = $thumbnail;
} elseif ($thumbnail->getResource() === null && $async === false) {
$this->refreshThumbnail($thumbnail);
}
return $thumbnail;
}
