[ // move from data-attribute to storage backend [ 'id' => 1, 'backend-class' => null, 'backend-ref' => 'f0c0d0i2', 'data' => 'without class', ], // move from storage-backend to maybe filesystem backend, skip at database backend [ 'id' => 2, 'backend-class' => 'Database', 'backend-ref' => 1, 'data' => '', ], // move data if invalid storage [ 'id' => 3, 'backend-class' => 'invalid!', 'backend-ref' => 'unimported', 'data' => 'invalid data moved', ], // skip everytime because of invalid storage and no data [ 'id' => 3, 'backend-class' => 'invalid!', 'backend-ref' => 'unimported', 'data' => '', ], ], 'storage' => [ [ 'id' => 1, 'data' => 'inside database', ], ], ];