Blobs can be used to store binary data in Google Cloud Datastore.
Example:
use Google\Cloud\ServiceBuilder;
$cloud = new ServiceBuilder();
$datastore = $cloud->datastore();
$blob = $datastore->blob(file_get_contents(__DIR__ .'/family-photo.jpg'));
Get the value of a blob by casting to a string.
echo (string) $blob;
public function testToString() { $blob = new Blob('hello world'); $this->assertEquals((string) $blob->get(), (string) $blob); }