Graphics Programs Reference
In-Depth Information
Create
BNRConnection
, the actor, as a new
NSObject
subclass.
BNRConnection
needs instance variables and properties to hold the connection, request, and callback.
Modify
BNRConnection.h
to look like this:
@interface BNRConnection : NSObject
<NSURLConnectionDelegate, NSURLConnectionDataDelegate>
{
NSURLConnection *internalConnection;
NSMutableData *container;
}
- (id)initWithRequest:(NSURLRequest *)req;
@property (nonatomic, copy) NSURLRequest *request;
@property (nonatomic, copy) void (^completionBlock)(id obj, NSError *err);
@property (nonatomic, strong) id <NSXMLParserDelegate> xmlRootObject;
- (void)start;
@end
For every request the
BNRFeedStore
makes, it will create an instance of
BNRCon-
nection
. An instance of this class is a one-shot deal: it runs, it calls back, and then it is
destroyed. The next time a request is made, another instance of
BNRConnection
will
be created. The store's responsibility here is to pass on the appropriate data (the request
and callback block) to the
BNRConnection
so that it can function. In other words, a
store object becomes a middle man: it takes the simple demands of a controller and sends
its
BNRConnection
minions off to carry out the work.
In addition to the request and callback, the store will provide an
xmlRootObject
to the
BNRConnection
. This object will be the object that eventually gets returned to the con-
troller. In this case, the
xmlRootObject
will be an instance of
RSSChannel
. The
