iPhone parsing url for GET params

Question

Hello, I have an string which is got from parsing an xml site.

http://www.arijasoft.com/givemesomthing.php?a=3434&b=435edsf&c=500

I want to have an NSString function that will be able to parse the value of c. Is there a default function or do i have to write it manually.

Answer 1

You could use Regular expression via RegExKit Lite: http://regexkit.sourceforge.net/RegexKitLite/

Or you could separate the string into components (which is less nice):

NSString *url=@"http://www.arijasoft.com/givemesomthing.php?a=3434&b=435edsf&c=500";
NSArray *comp1 = [url componentsSeparatedByString:@"?"];
NSString *query = [comp1 lastObject];
NSArray *queryElements = [query componentsSeparatedByString:@"&"];
for (NSString *element in queryElements) {
    NSArray *keyVal = [element componentsSeparatedByString:@"="];
    NSString *variableKey = [keyVal objectAtIndex:0];
    NSString *value = [keyVal lastObject];
}

Answer 2

Try the following:

NSURL *url = [NSURL URLWithString:@"http://www.arijasoft.com/givemesomthing.php?a=3434&b=435edsf&c=500"];
NSMutableString *parameterString = [NSMutableString stringWithFormat:@"{%@;}",[url parameterString]];
[parameterString replaceOccurrencesOfString:@"&" withString:@";"];
// Convert string into Dictionary
NSPropertyListFormat format;
NSString *error;    
NSDictionary *paramDict = [NSPropertyListSerialization propertyListFromData:[parameterString dataUsingEncoding:NSUTF8StringEncoding] mutabilityOption: NSPropertyListImmutable format:&format errorDescription:&error];

// Now take the parameter you want
NSString *value = [paramDict valueForKey:@"c"];

Answer 3

I made a class that does this parsing for you using an NSScanner, as an answer to the same question a few days ago. You might find it useful.

You can easily use it like:

    URLParser *parser = [[[URLParser alloc] initWithURLString:@"http://www.arijasoft.com/givemesomthing.php?a=3434&b=435edsf&c=500"] autorelease];
    NSString *c = [parser valueForVariable:@"c"];   //c=500