Change a NSURL's scheme - ios

Question

Is there an easy way to change the scheme of a NSURL? I do realize that NSURL is immutable. My goal is to change the scheme of an URL to "https" if the Security.framework is linked, and "http" if the framework is not linked. I do know how to detect if the framework is linked.
This code works wonderfully if the URL has no parameters (such as "?param1=foo&param2=bar"):
+(NSURL*)adjustURL:(NSURL*)inURL toSecureConnection:(BOOL)inUseSecure {
if ( inUseSecure ) {
return [[[NSURL alloc] initWithScheme:#"https" host:[inURL host] path:[inURL path]] autorelease];
}
else {
return [[[NSURL alloc] initWithScheme:#"http" host:[inURL host] path:[inURL path]] autorelease];
}
}
But if the URL does have parameters, [inURL path] drops them.
Any suggestions short of parsing the URL string myself (which I can do but I want to try not doing)? I do what to be able to pass URLs with either http or https to this method.

Answer 1

Updated answer
NSURLComponents is your friend here. You can use it to swap out the http scheme for https. The only caveat is NSURLComponents uses RFC 3986 whereas NSURL uses the older RFCs 1738 and 1808, so there is some behavior differences in edge cases, but you're extremely unlikely to hit those cases (and NSURLComponents has the better behavior anyway).
NSURLComponents *components = [NSURLComponents componentsWithURL:url resolvingAgainstBaseURL:YES];
components.scheme = inUseSecure ? #"https" : #"http";
return components.URL;
Original answer
Why not just do a bit of string manipulation?
NSString *str = [url absoluteString];
NSInteger colon = [str rangeOfString:#":"].location;
if (colon != NSNotFound) { // wtf how would it be missing
str = [str substringFromIndex:colon]; // strip off existing scheme
if (inUseSecure) {
str = [#"https" stringByAppendingString:str];
} else {
str = [#"http" stringByAppendingString:str];
}
}
return [NSURL URLWithString:str];

Answer 2

If you are using iOS 7 and later, you can use NSURLComponents, as show here
NSURLComponents *components = [NSURLComponents new];
components.scheme = #"http";
components.host = #"joris.kluivers.nl";
components.path = #"/blog/2013/10/17/nsurlcomponents/";
NSURL *url = [components URL];
// url now equals:
// http://joris.kluivers.nl/blog/2013/10/17/nsurlcomponents/

Answer 3

Swift5
extension URL {
func settingScheme(_ value: String) -> URL {
let components = NSURLComponents.init(url: self, resolvingAgainstBaseURL: true)
components?.scheme = value
return (components?.url!)!
}
}
Usage
if nil == url.scheme { url = url.settingScheme("file") }

Answer 4

Perhaps using the resourceSpecifier would help:
return [[[NSURL alloc] initWithString:[NSString stringWithFormat:#"https:%#", [inURL resourceSpecifier]]]];

Answer 5

NSString *newUrlString = [NSString stringWithFormat:#"https://%#%#",
inURL.host, inURL.path];
if (inURL.query) {
newUrlString = [newUrlString stringByAppendingFormat:#"?%#", inURL.query];
}
return [NSURL URLWithString:newUrl];
[NOTE]
Code related to port and other fields handling are removal for simplicity.

Answer 6

I did it like this, using a variable resourceSpecifier in NSURL
SWIFT
var resourceSpecifier: String? { get }
OBJECTIVE-C
#property(readonly, copy) NSString *resourceSpecifier Discussion
This property contains the resource specifier. For example, in the URL http://www.example.com/index.html?key1=value1#jumplink, the resource specifier is //www.example.com/index.html?key1=value1#jumplink (everything after the colon).
-(NSURL*) URLByReplacingScheme
{
NSString *newUrlString = kHttpsScheme;
if([self.scheme isEqualToString:kEmbeddedScheme])
newUrlString = kHttpScheme;
newUrlString = [newUrlString stringByAppendingString:[NSString stringWithFormat:#":%#", self.resourceSpecifier]];
return [NSURL URLWithString:newUrlString];
}