Parsing simple XML in Objective-C - objective-c

Question

I have the following very simple XML returned from a webserver which I use ASIHttpRequest to connect to:
<element1>something</element1>
<element2>somethingelse</element2>
<element3>anotherthing</element3>
ASIHttpRequest can return it as NSData or NSString. I need to parse the information, what is the easiest way to do so?
Thanks

Answer 1

There are some XML parsers available for iOS NSXMLParser, libxml2 (DOM and SAX),TBXML,KissXML. You can refer http://www.raywenderlich.com/553/how-to-chose-the-best-xml-parser-for-your-iphone-project to choose best XML Parser (Speed and memory footprint). Easiest would be TBXML. NSXMLParser is easy as well.
NSXMLParser* xmlParser = [[NSXMLParser alloc] initWithData:receivedXMLData];//init NSXMLParser with receivedXMLData
[xmlParser setDelegate:self]; // Set delegate for NSXMLParser
[xmlParser parse]; //Start parsing
[xmlParser release];
//Delegate Methods
//Have a instance variable NSMutableString* currentString; to hold data between elements and NSMutableArray* elementsArray; to hold parsed data
- (void)parserDidStartDocument:(NSXMLParser *)parser
{
elementsArray = [[NSMutableArray alloc] init];
}
//store all found characters between elements in currentString mutable string
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
if(!currentString)
{
currentString = [[NSMutableString alloc] init];
}
[currentString appendString:string];
}
//When end of XML tag is found this method gets notified
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
if([elementName isEqualToString:#"element1"])
{
[elementsArray addObject:currentString];
[currentString release],currentString=nil;
return;
}
if([elementName isEqualToString:#"element2"])
{
[elementsArray addObject:currentString];
[currentString release],currentString=nil;
return;
}
if([elementName isEqualToString:#"element3"])
{
[elementsArray addObject:currentString];
[currentString release],currentString=nil;
return;
}
[currentString release],currentString =nil;
}
//Parsing has ended
- (void)parserDidEndDocument:(NSXMLParser *)parser
{
NSLog(#"Content of Elements Array: %#",elementsArray);
[elementsArray release],elementsArray=nil;
}
- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError
{
UIAlertView* parseErrorAlert = [[UIAlertView alloc] initWithTitle:#"Parse Error" message:[NString stringWithFormat:"%#",[parseError localizedDescription]] delegate:nil cancelButtonTitle:#"Ok" otherButtonTitles:nil];
[parseErrorAlert show];
[parseErrorAlert release];
}
You have other delegate methods too like parseErrorOccured. Refer http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSXMLParser_Class/Reference/Reference.html
For TBXML : http://tbxml.co.uk/TBXML/API.html
Updated: Implemented parseError delegate method and valid xml example
XML You posted in code is not a valid XML (You can check XML validation online: http://validator.w3.org/#validate_by_input) so it will throw an parseError. Here is valid XML for XML you posted in question:
<?xml version="1.0"?>
<root>
<element1>something</element1>
<element2>somethingelse</element2>
<element3>anotherthing</element3>
</root>

Answer 2

Try also XMLObject. This may helps if you want to keep your cocoa style in your project.