Prazi Prazi - 2 months ago 15
Objective-C Question

NSRegularExpression to extract text between two XML tags

How to extract the value "6" between the "badgeCount" tags using NSRegularExpression. Following is the response from the server:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><badgeCount>6</badgeCount><rank>2</rank><screenName>myName</screenName>


Following is the code I tried but not getting success. Actually it goes in else part and prints "Value of regex is nil":

NSString *responseString = [[NSString alloc] initWithBytes:[responseDataForCrntUser bytes] length:responseDataForCrntUser.length encoding:NSUTF8StringEncoding];

NSError *error;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(?<=badgeCount>)(?:[^])*?(?=</badgeCount)" options:0 error:&error];
if (regex != nil) {
NSTextCheckingResult *firstMatch = [regex firstMatchInString:responseString options:0 range:NSMakeRange(0, [responseString length])];
NSLog(@"NOT NIL");
if (firstMatch) {
NSRange accessTokenRange = [firstMatch rangeAtIndex:1];
NSString *value = [urlString substringWithRange:accessTokenRange];
NSLog(@"Value: %@", value);
}
}
else
NSLog(@"Value of regex is nil");


If you could provide sample code that would be much appreciated.

Thanks in advance.

NOTE: I don't want to use NSXMLParser.

Answer

Example:

NSString *xml = @"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><badgeCount>6</badgeCount><rank>2</rank><screenName>myName</screenName>";
NSString *pattern = @"<badgeCount>(\\d+)</badgeCount>";

NSRegularExpression *regex = [NSRegularExpression
                                      regularExpressionWithPattern:pattern
                                      options:NSRegularExpressionCaseInsensitive
                                      error:nil];
NSTextCheckingResult *textCheckingResult = [regex firstMatchInString:xml options:0 range:NSMakeRange(0, xml.length)];

NSRange matchRange = [textCheckingResult rangeAtIndex:1];
NSString *match = [xml substringWithRange:matchRange];
NSLog(@"Found string '%@'", match);

NSLog output:

Found string '6'
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