如何使用字符串在Qt中使用套接字发送/接收XML数据？

Question

I have a Qt TCP Server and Client program which can interact with each other. The Server can send some function generated data to the socket using Qtextstream . And the Client reads the data from the socket using simple readAll() and displays to a QtextEdit.

Now my data from Server side is huge (around 7000+ samples ) and I need the data to appear on the Client side instantaneously. I have learned that using XML will help in my case. So, I made an Qt XML Server and it generates the whole xml data into a .xml file. I read the .xml file in Client side and I can get to display its contents. I used the DOM method for parsing. But I get the data to display only when all the 7000+ samples have been generated on the Server side.

I need clarifications on these questions:

1. How do I write each element of the XML Server side in to a String and send them through socket? I learnt tagName() can help me, but I have not been able to figure out how.
2. Is there any other way other than the String method to get a single element generated in the Server side to appear in the Client side.

PS: I am a newbie, forgive my ignorance. Thank you.

Answer 1

Most DOM XML parsers require a complete, well-formed XML document before they'll do anything with it. That's precisely what you see: your data is processed only after all of the samples have been received.

You need to use an incremental parser that doesn't care about the XML document not being complete yet.

On the other hand: if you're not requiring XML for interoperability with 3rd party systems, you're probably wasting a lot of resources by using it. I don't know where you've "learned" that XML will "help in your case". To me it's not learning, it's just following the crowd without understanding what's going on. Is your requirement to use XML or to move the data around? Moving data around has been a well understood problem for decades. Computers "speak" binary. No need to work around it, you know. If all you need is to move around some numbers, use QDataStream and be done with it. It'll be two orders of magnitude faster than the fastest XML parsers, you'll transmit an order of magnitude less data, and everyone will live happily ever after*.

*living happily ever after not guaranteed, individual results may vary.