Faster XML reading required in iPhone - iphone

Question

I have following code - methods to read XML files. But it works very slow for me. Isn't there any sufficient way to fetch and read data faster?
if(connectionRemaining)
{
[self LoadingPopUp];
NSURL *tmpURl=[NSURL URLWithString:[NSString stringWithFormat:#"%#getcategory.php",[iGolfAppDelegate getServerPath]]];
NSMutableURLRequest *theRequest=[NSMutableURLRequest requestWithURL:tmpURl];
NSURLConnection *conn=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if(conn)
myWebData=[[NSMutableData data] retain];
connectionRemaining=NO;
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[myWebData setLength: 0];
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[myWebData appendData:data];
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
[connection release];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection {
// NSString *theXML = [[NSString alloc] initWithBytes: [myWebData mutableBytes] length:[myWebData length] encoding:NSUTF8StringEncoding];
// NSLog(#"%#",theXML);[theXML release];
if( myXMLParser )
[myXMLParser release];
myXMLParser = [[NSXMLParser alloc] initWithData: myWebData];
[myXMLParser setDelegate: self]; [myXMLParser setShouldResolveExternalEntities: YES];
[myXMLParser parse];[connection release];[myWebData release];
}
#pragma mark
#pragma mark XMLParsing Methods
-(void)parser:(NSXMLParser*)parser didStartElement:(NSString*)elementName namespaceURI:(NSString*)namespaceURI qualifiedName:(NSString*)qualifiedName attributes:(NSDictionary*)attributeDict {
if([elementName isEqualToString:#"category"])
categoryArray=[[NSMutableArray alloc]init];
else if([elementName isEqualToString:#"Prop_Category"])
aCategory=[[Category alloc] init];
}
-(void)parser:(NSXMLParser*)parser foundCharacters:(NSString*)string {
if(!currentElementValue)
currentElementValue=[[NSMutableString alloc] initWithString:string];
else
[currentElementValue appendString:string];
}
-(void)parser:(NSXMLParser*)parser didEndElement:(NSString*)elementName namespaceURI:(NSString*)namespaceURI qualifiedName:(NSString*)qualifiedName {
if([elementName isEqualToString:#"category"])
{ [LoadingAlert dismissWithClickedButtonIndex:0 animated:YES]; [LoadingAlert release];[self categoryPickerDiplay]; return; }
else if([elementName isEqualToString:#"Prop_Category"])
{ [categoryArray addObject:aCategory];[aCategory release];aCategory=nil; }
else{
[aCategory setValue:currentElementValue forKey:elementName];
[currentElementValue release];currentElementValue=nil;
}
}
Let me clarify my question again.
I have observed that this way of reading XML is not sufficient. By using this way iPhone loads data very slowly. Because, iPhone will read & compare each tag every time.
I want some faster XML loading & parsing.

Answer 1

There's an example from Apple called XMLPerformance that illustrates libxml vs. NSXMLParser in terms of performance. Check out its implementation of libxml.

Answer 2

The SiesmicXML and TopSongs code samples from adc show some ways of parsing XML that cause a minimum of user wait time.

Answer 3

Have you looked at the libxml C library, or the TouchXML wrapper for it? Also, are you sure that it's the NSXMLParser that's causing your slowdown? You might want to do a quick runthrough using Instruments or Shark to profile the application and find the hotspots.