Objective C - Know when a method finish

I explain better my question : when my app start, some xml have been downloaded from the internet and this files have been parsed. I have 8 xml file开发者_如何学运维. My question is : how can i know when really the parser finish to parse? And when all data is ready to download?

If you're using NSXMLParser, then your delegate is notified when the end of the document is reached using – parserDidEndDocument: