Craft CMS rename asset and title on asset save

gist.php

<?php

protected function initSaveAssetEventListeners()
{
    craft()->on('assets.saveAsset', function(Event $event) {
        if ($event->params['isNewAsset']) {
            $asset = $event->params['asset'];
            $source = $asset->getSource();

            if (in_array($source->handle, ['myAssetSource'])) {
                $extension = IOHelper::getExtension($asset->filename);
                $filename = StringHelper::randomString(32, false).'.'.$extension;
                $filename = StringHelper::toLowerCase($filename);
                $title = $asset->generateAttributeLabel(IOHelper::getFileName($filename, false));

                // Rename the actual file on the server
                craft()->assets->renameFile($asset, $filename);

                // Update the asset's filename and title in the database
                $asset->getContent()->title = $title;
                $asset->setAttribute('filename', $filename);
                craft()->assets->storeFile($asset);
            }
        }
    });
}