Iphone Programming XML Parser NSMutableArray - iphone

Question

I am currently having a problem with parsing information from an XML into an NSMutableArray, i have pasted the code below which is for the parser this retrieves the document off the internet and constructs the array. I am then trying to copy the items from the xml parser into an NSMutableArray for searching, but every time i try to copy the array it returns a struct error so i have removed the changes for now.
Here is the code for the parser and the current code for the viewdidload in the main view controller, if anyone can help i would really appreciate it.
#import "BlogRssParser.h"
#import "BlogRss.h"
#implementation BlogRssParser
#synthesize currentItem = _currentItem;
#synthesize currentItemValue = _currentItemValue;
#synthesize rssItems = _rssItems;
#synthesize delegate = _delegate;
#synthesize retrieverQueue = _retrieverQueue;
- (id)init{
if(![super init]){
return nil;
}
_rssItems = [[NSMutableArray alloc]init];
return self;
}
- (NSOperationQueue *)retrieverQueue {
if(nil == _retrieverQueue) {
_retrieverQueue = [[NSOperationQueue alloc] init];
_retrieverQueue.maxConcurrentOperationCount = 1;
}
return _retrieverQueue;
}
- (void)startProcess{
SEL method = #selector(fetchAndParseRss);
[[self rssItems] removeAllObjects];
NSInvocationOperation *op = [[NSInvocationOperation alloc] initWithTarget:self
selector:method
object:nil];
[self.retrieverQueue addOperation:op];
[op release];
}
-(BOOL)fetchAndParseRss{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
//To suppress the leak in NSXMLParser
[[NSURLCache sharedURLCache] setMemoryCapacity:0];
[[NSURLCache sharedURLCache] setDiskCapacity:0];
NSURL *url = [NSURL URLWithString:#"http://xxxxxxxxx.co.uk/rssparser/Data.xml"];
BOOL success = NO;
NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL:url];
[parser setDelegate:self];
[parser setShouldProcessNamespaces:YES];
[parser setShouldReportNamespacePrefixes:YES];
[parser setShouldResolveExternalEntities:NO];
success = [parser parse];
[parser release];
[pool drain];
return success;
}
- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qualifiedName attributes:(NSDictionary *)attributeDict{
if(nil != qualifiedName){
elementName = qualifiedName;
}
if ([elementName isEqualToString:#"item"]) {
self.currentItem = [[[BlogRss alloc]init]autorelease];
} else if([elementName isEqualToString:#"title"] ||
[elementName isEqualToString:#"description"] ||
[elementName isEqualToString:#"mediaUrl"] ||
[elementName isEqualToString:#"link"] ||
[elementName isEqualToString:#"guid"] ||
[elementName isEqualToString:#"pubDate"]) {
self.currentItemValue = [NSMutableString string];
} else {
self.currentItemValue = nil;
}
}
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {
if(nil != qName){
elementName = qName;
}
if([elementName isEqualToString:#"title"]){
self.currentItem.title = self.currentItemValue;
}else if([elementName isEqualToString:#"description"]){
self.currentItem.description = self.currentItemValue;
}else if([elementName isEqualToString:#"link"]){
self.currentItem.linkUrl = self.currentItemValue;
}else if([elementName isEqualToString:#"mediaUrl"]){
self.currentItem.mediaUrl = self.currentItemValue;
}else if([elementName isEqualToString:#"guid"]){
self.currentItem.guidUrl = self.currentItemValue;
}else if([elementName isEqualToString:#"pubDate"]){
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"yyyy-MM-dd'T'HH:mm:ss'Z'"];
self.currentItem.pubDate = [formatter dateFromString:self.currentItemValue];
[formatter release];
}else if([elementName isEqualToString:#"item"]){
[[self rssItems] addObject:self.currentItem];
}
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {
if(nil != self.currentItemValue){
[self.currentItemValue appendString:string];
}
}
- (void)parser:(NSXMLParser *)parser foundCDATA:(NSData *)CDATABlock{
//Not needed for now
}
- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError{
if(parseError.code != NSXMLParserDelegateAbortedParseError) {
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[(id)[self delegate] performSelectorOnMainThread:#selector(processHasErrors)
withObject:nil
waitUntilDone:NO];
}
}
- (void)parserDidEndDocument:(NSXMLParser *)parser {
[(id)[self delegate] performSelectorOnMainThread:#selector(processCompleted)
withObject:nil
waitUntilDone:NO];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}
-(void)dealloc{
self.currentItem = nil;
self.currentItemValue = nil;
self.delegate = nil;
[_rssItems release];
[super dealloc];
}
#end
BlogRSSParser.h
#import <Foundation/Foundation.h>
#class BlogRss;
#protocol BlogRssParserDelegate;
#interface BlogRssParser : NSObject <NSXMLParserDelegate>{
BlogRss * _currentItem;
NSMutableString * _currentItemValue;
NSMutableArray * _rssItems;
id<BlogRssParserDelegate> _delegate;
NSOperationQueue *_retrieverQueue;
}
#property(nonatomic, retain) BlogRss * currentItem;
#property(nonatomic, retain) NSMutableString * currentItemValue;
#property(readonly) NSMutableArray * rssItems;
#property(nonatomic, assign) id<BlogRssParserDelegate> delegate;
#property(nonatomic, retain) NSOperationQueue *retrieverQueue;
- (void)startProcess;
#end
#protocol BlogRssParserDelegate <NSObject>
-(void)processCompleted;
-(void)processHasErrors;
#end
ViewDidLoad
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
[super viewDidLoad];
[self toolbarInit];
_rssParser = [[BlogRssParser alloc]init];
self.rssParser.delegate = self;
[[self rssParser]startProcess];
}

Answer 1

You rssItems array is marked "readonly".
Change:
#property(readonly) NSMutableArray * rssItems;
to
#property(nonatomic, retain) NSMutableArray * rssItems;