JonasG JonasG - 6 months ago 20
iOS Question

Best way to parse URL string to get values for keys?

I need to parse a URL string like this one:

&ad_eurl=http://www.youtube.com/video/4bL4FI1Gz6s&hl=it_IT&iv_logging_level=3&ad_flags=0&endscreen_module=http://s.ytimg.com/yt/swfbin/endscreen-vfl6o3XZn.swf&cid=241&cust_gender=1&avg_rating=4.82280613104


I need to split the NSString up into the signle parts like
cid=241
and
&avg_rating=4.82280613104
. I've been doing this with
substringWithRange:
but the values return in a random order, so that messes it up. Is there any class that allows easy parsing where you can basically convert it to NSDictionary to be able to read the value for a key (for example ValueForKey:
cid
should return
241
). Or is there just another easier way to parse it than using
NSMakeRange
to get a substring?

Answer

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.