urllib alternative for iPhone

I am trying to create an iPhone application which in some point connects to the internet, fills an on-line form, fetches the resulting website, parses it and returns a string to the user. I want all this process to happen in the background. I kn开发者_JAVA技巧ow how to do this kind of things with python and urllib but in objc I can't find an alternative, from on-line search I found either sites that explain how to use webkit to retrieve webpages (I suppose this is for displaying them to the user) or how to parse an existing HTML file or string. Since I want the file to be retrieved from the internet and the whole process should be running in the background, neither of these solutions covers my needs.

Use NSURLConnection and implement the delegates. You could also use ASIHTTPRequest