Graphics Programs Reference
In-Depth Information
BNRConnection
class is pretty handy - you can use that in any application. In fact, that
very same class is in a number of applications that are currently on the App Store.)
Another request
Now that we have
BNRConnection
and a store object, adding new requests for the
store to handle is really straight-forward. Let's have the
BNRFeedStore
fetch the top
songs from
iTunes
. First, we need to make a minor change to the
RSSChannel
and
RSSItem
classes because Apple's RSS feed uses a different element name (
entry
) to
identify items in their RSS feed. In
RSSChannel.m
, modify
pars-
er:didStartElement:namespaceURI:qualifiedName:attributes:
to
create an
RSSItem
when it encounters the
entry
element.
- (void)parser:(NSXMLParser *)parser
didStartElement:(NSString *)elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qualifiedName
attributes:(NSDictionary *)attributeDict
{
if ([elementName isEqual:@"title"]) {
currentString = [[NSMutableString alloc] init];
[self setTitle:currentString];
}
else if ([elementName isEqual:@"description"]) {
currentString = [[NSMutableString alloc] init];
[self setInfoString:currentString];
} else if ([elementName isEqual:@"item"]
|| [elementName isEqual:@"entry"]) {
RSSItem *entry = [[RSSItem alloc] init];
[entry setParentParserDelegate:self];
[parser setDelegate:entry];
[items addObject:entry];
}
}
Then in
RSSItem.m
, have the
RSSItem
return control to the channel when it ends an
entry
element.
- (void)parser:(NSXMLParser *)parser
didEndElement:(NSString *)elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qName
{
currentString = nil;
if ([elementName isEqual:@"item"]
