Best way to parse URL string to get values for keys?
edit (June 2018): this answer is better. Apple added NSURLComponents
in iOS 7.
I would create a dictionary, get an array of the key/value pairs with
NSMutableDictionary *queryStringDictionary = [[NSMutableDictionary alloc] init];
NSArray *urlComponents = [urlString componentsSeparatedByString:@"&"];
Then populate the dictionary :
for (NSString *keyValuePair in urlComponents)
{
NSArray *pairComponents = [keyValuePair componentsSeparatedByString:@"="];
NSString *key = [[pairComponents firstObject] stringByRemovingPercentEncoding];
NSString *value = [[pairComponents lastObject] stringByRemovingPercentEncoding];
[queryStringDictionary setObject:value forKey:key];
}
You can then query with
[queryStringDictionary objectForKey:@"ad_eurl"];
This is untested, and you should probably do some more error tests.
I also answered this at https://stackoverflow.com/a/26406478/215748.
You can use queryItems
in URLComponents
.
When you get this property’s value, the NSURLComponents class parses the query string and returns an array of NSURLQueryItem objects, each of which represents a single key-value pair, in the order in which they appear in the original query string.
let url = "http://example.com?param1=value1¶m2=param2"
let queryItems = URLComponents(string: url)?.queryItems
let param1 = queryItems?.filter({$0.name == "param1"}).first
print(param1?.value)
Alternatively, you can add an extension on URL to make things easier.
extension URL {
var queryParameters: QueryParameters { return QueryParameters(url: self) }
}
class QueryParameters {
let queryItems: [URLQueryItem]
init(url: URL?) {
queryItems = URLComponents(string: url?.absoluteString ?? "")?.queryItems ?? []
print(queryItems)
}
subscript(name: String) -> String? {
return queryItems.first(where: { $0.name == name })?.value
}
}
You can then access the parameter by its name.
let url = URL(string: "http://example.com?param1=value1¶m2=param2")!
print(url.queryParameters["param1"])