Get parts of a NSURL in objective-c
I have an NSString with the value of
http://digg.com/news/business/24hr
How can I get everything before the 3rd level?
http://digg.com/news/
This isn't exactly the third level, mind you. An URL is split like that way:
- the protocol or scheme (here,
http
) - the
://
delimiter - the username and the password (here there isn't any, but it could be
username:password@hostname
) - the host name (here,
digg.com
) - the port (that would be
:80
after the domain name for instance) - the path (here,
/news/business/24hr
) - the parameter string (anything that follows a semicolon)
- the query string (that would be if you had GET parameters like
?foo=bar&baz=frob
) - the fragment (that would be if you had an anchor in the link, like
#foobar
).
A "fully-featured" URL would look like this:
http://foobar:[email protected]:8080/some/path/file.html;params-here?foo=bar#baz
NSURL
has a wide range of accessors. You may check them in the documentation for the NSURL
class, section Accessing the Parts of the URL. For quick reference:
-
-[NSURL scheme]
= http -
-[NSURL resourceSpecifier]
= (everything from // to the end of the URL) -
-[NSURL user]
= foobar -
-[NSURL password]
= nicate -
-[NSURL host]
= example.com -
-[NSURL port]
= 8080 -
-[NSURL path]
= /some/path/file.html -
-[NSURL pathComponents]
= @["/", "some", "path", "file.html"] (note that the initial / is part of it) -
-[NSURL lastPathComponent]
= file.html -
-[NSURL pathExtension]
= html -
-[NSURL parameterString]
= params-here -
-[NSURL query]
= foo=bar -
-[NSURL fragment]
= baz
What you'll want, though, is something like that:
NSURL* url = [NSURL URLWithString:@"http://digg.com/news/business/24hr"];
NSString* reducedUrl = [NSString stringWithFormat:
@"%@://%@/%@",
url.scheme,
url.host,
url.pathComponents[1]];
For your example URL, what you seem to want is the protocol, the host and the first path component. (The element at index 0 in the array returned by -[NSString pathComponents]
is simply "/", so you'll want the element at index 1. The other slashes are discarded.)
Playground provides an interactive way of seeing this in action. I hope you can enjoy doing the same, a fun way to learn NSURL an important topic in iOS.