PHP7

When it comes to parsing XML/CSV/JSON/... documents, there are 2 approaches to consider. DOM loading loads all the documents, making it easy to navigate and parse, and as such provides maximum flexibility for developers. Streaming implies iterating through the document, acts like a cursor, and stops at each element in its way, thus avoiding memory overkill. Thus, when it comes to big files, callbacks will be executed meanwhile file is downloading and will be much more efficient as far as memory is concerned.