how to load xml into memory in faster way? - iphone

Question

I am new to objective-c. I load the whole xml string from server to an nsxml parser like below: but the problem is loding from url to memory takes much more time than parsing it. how can i solve that? (my app is very slow)
xmlString = [[NSMutableString alloc] initWithContentsOfURL:url usedEncoding:&NSUTF8StringEncoding error:&error];
NSData *xmlData = [xmlString dataUsingEncoding:NSUTF8StringEncoding];
NSXMLParser *parser = [[NSXMLParser alloc] initWithData:xmlData];

Answer 1

Run your XML Parser in different Thread.(this will not make your parsing faster)
How To Choose The Best XML Parser for Your iPhone Project

Answer 2

Basically NSXMLParser is slow. There is a possibility of finding a better parser for the specific need. A true stream parser might help if you do not need the entire DOM and validation.

Answer 3

Don't use
xmlString = [[NSMutableString alloc] initWithContentsOfURL:url usedEncoding:&NSUTF8StringEncoding error:&error];
Use a network library like ASIHTTPRequest to load the content from a URL and then parse it.
Loading directly from URL like you've done will hang your app till the data is loaded.
Download and install that library as given in the instructions (it's easy), then you can do
{
//in some function
NSURL *url = [NSURL URLWithString:urlString];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request startAsynchronous]; //this will load URL in background
}
- (void)requestFinished:(ASIHTTPRequest *)request
{
// Use when fetching text data
NSString *responseString = [request responseString];
//parse the XML here
[self parseXML:responseString];
}
- (void)requestFailed:(ASIHTTPRequest *)request
{
NSError *error = [request error];
}

Answer 4

You cannot load the xml faster from the url as it totally depends on your internet connection.
To keep your application smooth, you need to parse the xml in another thread. I answered a similar question in the following url
How to handle freezing programm at loading xml from bad url?
Also there are faster XML parser than the defaul NSXMLParser. There is a good introduction about them in the following blog post. So you can use any of these parser in place of NSXMLParser to improve the performance of your application.
http://www.raywenderlich.com/553/how-to-chose-the-best-xml-parser-for-your-iphone-project
I hope that it may clarify a little bit of your question.