hi can anyone give me hint of how to start coding for an app to search the internet and find the rss xml url's using a string provided by the 开发者_运维问答user.

thanks upfront.

You need to use XML parsing to implement this.I suggest use touchXML

-(void)callwebservice{

NSString *path = @"YOUR URL";
[self grabRSSFeed:path];

}

pragma mark -

pragma mark Touch XML

pragma mark -

-(void) grabRSSFeed:(NSString *)blogAddress {

// Initialize the blogEntries MutableArray that we declared in the header
blogEntries = [[NSMutableArray alloc] init];    

// Convert the supplied URL string into a usable URL object
NSURL *url = [NSURL URLWithString: blogAddress];

// Create a new rssParser object based on the TouchXML "CXMLDocument" class, this is the
// object that actually grabs and processes the RSS data
CXMLDocument *rssParser = [[[CXMLDocument alloc] initWithContentsOfURL:url options:0 error:nil] autorelease];

// Create a new Array object to be used with the looping of the results from the rssParser
NSArray *resultNodes = NULL;

// Set the resultNodes Array to contain an object for every instance of an  node in our RSS feed
resultNodes = [rssParser nodesForXPath:@"//Node you want to parse" error:nil];

// Loop through the resultNodes to access each items actual data
for (CXMLElement *resultElement in resultNodes) {
    
    // Create a temporary MutableDictionary to store the items fields in, which will eventually end up in blogEntries
    NSMutableDictionary *blogItem = [[NSMutableDictionary alloc] init];
    // Create a counter variable as type "int"
    int counter;
    
    // Loop through the children of the current  node
    for(counter = 0; counter < [resultElement childCount]; counter++) {
        // Add each field to the blogItem Dictionary with the node name as key and node value as the value
        [blogItem setObject:[[resultElement childAtIndex:counter] stringValue] forKey:[[resultElement childAtIndex:counter] name]];
                    NSLog(@"Data = %@",[[resultElement childAtIndex:counter] stringValue]);
        
    }
    
    // Add the blogItem to the global blogEntries Array so that the view can access it.
    [blogEntries addObject:[blogItem copy]];
    
}
        [YourTable reloadData];

}

Import touchXML library in you header file.

Thanks