UITableView has Empty Rows - ios

Question

I'm having a problem with RSS feeds in a table view in an iOS app. I originally tested the RSS feed in it's project with the table view as the root view. I'm trying to get the same functionality in a different project but the table view that displays the list of articles from the RSS feed is blank. The code for the table view in the new project is the same. The only different is that I have a different root view controller that has a bunch of buttons. One button is supposed to go to that table view and it does but the rows are empty. I'm thinking this may be an issue with how the root view controller is set up since I know the table view is populated when that code is run by itself. Here are the AppDelegate files where it sets the root view controller.
//
// KFBAppDelegate.h
// KFBNewsroom
//
// Created by KFB on 10/15/12.
// Copyright (c) 2012 com.kfb. All rights reserved.
//
#import <UIKit/UIKit.h>
#class KFBViewController;
#interface KFBAppDelegate : UIResponder <UIApplicationDelegate>
#property (strong, nonatomic) UIWindow *window;
#property (strong, nonatomic) KFBViewController *viewController;
#end
//
// KFBAppDelegate.m
// KFBNewsroom
//
// Created by KFB on 10/15/12.
// Copyright (c) 2012 com.kfb. All rights reserved.
//
#import "KFBAppDelegate.h"
#import "KFBViewController.h"
#import "ListViewController.h"
#import "WebViewController.h"
#import "ActionAlertsViewController.h"
#import "MarketUpdatesViewController.h"
#implementation KFBAppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.viewController = [[KFBViewController alloc] initWithNibName:#"KFBViewController" bundle:nil];
ListViewController *lvc = [[ListViewController alloc]initWithStyle:UITableViewStylePlain];
WebViewController *wvc = [[WebViewController alloc]init];
[lvc setWebViewController:wvc];
ActionAlertsViewController *avc = [[ActionAlertsViewController alloc]initWithStyle:UITableViewStylePlain];
[avc setWebViewController:wvc];
MarketUpdatesViewController *mvc = [[MarketUpdatesViewController alloc]initWithStyle:UITableViewStylePlain];
[mvc setWebViewController:wvc];
self.window.rootViewController = self.viewController;
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
return YES;
}
//
// ListViewController.h
// Nerdfeed
//
// Created by KFB on 10/16/12.
// Copyright (c) 2012 com.kfb. All rights reserved.
//
#import <Foundation/Foundation.h>
// #interface ListViewController : NSObject
// a forward declaration; we'll import the header in the .m
#class RSSChannel;
#class WebViewController;
#interface ListViewController : UITableViewController
<NSXMLParserDelegate>
{
NSURLConnection *connection;
NSMutableData *xmlData;
RSSChannel *channel;
}
#property (nonatomic, strong)WebViewController *webViewController;
- (void)fetchEntries;
#end
//
// ListViewController.m
// Nerdfeed
//
// Created by KFB on 10/16/12.
// Copyright (c) 2012 com.kfb. All rights reserved.
//
#import "ListViewController.h"
#import "RSSChannel.h"
#import "RSSItem.h"
#import "WebViewController.h"
#implementation ListViewController
#synthesize webViewController;
- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI: (NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
NSLog(#"%# found a %# element", self, elementName);
if ([elementName isEqual:#"channel"])
{
// If the parser saw a channel, create new instance, store in our ivar
channel = [[RSSChannel alloc]init];
// Give the channel object a pointer back to ourselves for later
[channel setParentParserDelegate:self];
// Set the parser's delegate to the channel object
[parser setDelegate:channel];
}
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// return 0;
return [[channel items]count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
// return nil;
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"UITableViewCell"];
if (cell == nil)
{
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"UITableViewCell"];
}
RSSItem *item = [[channel items]objectAtIndex:[indexPath row]];
[[cell textLabel]setText:[item title]];
return cell;
}
- (void)fetchEntries
{
// Create a new data container for the stuff that comes back from the service
xmlData = [[NSMutableData alloc]init];
// Construct a URL that will ask the service for what you want -
// note we can concatenate literal strings together on multiple lines in this way - this results in a single NSString instance
NSURL *url = [NSURL URLWithString:#"http://kyfbnewsroom.com/category/public- affairs/feed"];
// Put that URL into an NSURLRequest
NSURLRequest *req = [NSURLRequest requestWithURL:url];
// Create a connection that will exchange this request for data from the URL
connection = [[NSURLConnection alloc]initWithRequest:req delegate:self startImmediately:YES];
}
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self)
{
[self fetchEntries];
}
return self;
}
// This method will be called several times as the data arrives
- (void)connection:(NSURLConnection *)conn didReceiveData:(NSData *)data
{
// Add the incoming chunk of data to the container we are keeping
// The data always comes in the correct order
[xmlData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)conn
{
/* We are just checking to make sure we are getting the XML
NSString *xmlCheck = [[NSString alloc]initWithData:xmlData encoding:NSUTF8StringEncoding];
NSLog(#"xmlCheck = %#", xmlCheck);*/
// Create the parser object with the data received from the web service
NSXMLParser *parser = [[NSXMLParser alloc]initWithData:xmlData];
// Give it a delegate - ignore the warning here for now
[parser setDelegate:self];
//Tell it to start parsing - the document will be parsed and the delegate of NSXMLParser will get all of its delegate messages sent to it before this line finishes execution - it is blocking
[parser parse];
// Get rid of the XML data as we no longer need it
xmlData = nil;
// Reload the table.. for now, the table will be empty
[[self tableView]reloadData];
NSLog(#"%#\n %#\n %#\n", channel, [channel title], [channel infoString]);
}
- (void)connection:(NSURLConnection *)conn didFailWithError:(NSError *)error
{
// Release the connection object, we're done with it
connection = nil;
// Release the xmlData object, we're done with it
xmlData = nil;
// Grab the description of the error object passed to us
NSString *errorString = [NSString stringWithFormat:#"Fetch failed: %#", [error localizedDescription]];
// Create and show an alert view with this error displayed
UIAlertView *av = [[UIAlertView alloc]initWithTitle:#"Error" message:errorString delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[av show];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Push the web view controller onto the navigation stack - this implicitly creates the web view controller's view the first time through
[[self navigationController]pushViewController:webViewController animated:YES];
// Grab the selected item
RSSItem *entry = [[channel items]objectAtIndex:[indexPath row]];
// Construct a URL with the link string of the item
NSURL *url = [NSURL URLWithString:[entry link]];
// Construct a request object with that URL
NSURLRequest *req = [NSURLRequest requestWithURL:url];
// Load the request into the web view
[[webViewController webView]loadRequest:req];
// Set the title of the web view controller's navigation item
[[webViewController navigationItem]setTitle:[entry title]];
}
#end

Answer 1

Your ListViewController class must inherit from UITableViewController
Edit: Sorry I didn't see it, just add the delegate & dataSource
#interface ListViewController : UITableViewController
<NSXMLParserDelegate, UITableViewDelegate, UITableViewDataSource>
Did you add:
-(void)viewDidLoad {
[super viewDidLoad];
[tableView setDelegate: self];
[tableView setDataSource: self];
}
On implementation of ListViewController (Like after #synthesize webViewController;
)?

Answer 2

Make sure you set up the UITableView DataSource so that you can actually display rows. You'll probably need to set the delegate too.
EDIT:
You're still not setting the UITableView delegate or datasource. You need to do that so that the UITableView knows where to get data from. I think the best place for you to put that is in your ListViewController's viewDidLoad method
-(void)viewDidLoad {
[super viewDidLoad];
[tableView setDelegate: self];
[tableView setDataSource: self];
}
You'll also need to add the UITableViewDelegate and UITableViewDataSource protocols to ListViewController.
EDIT 2:
Make sure you're adding the UITableViewDataSource and UITableViewDelegate protocols to ListViewController
#interface ListViewController : UITableViewController
<NSXMLParserDelegate, UITableViewDelegate, UITableViewDataSource>
Also, make sure the viewDidLoad method above is in the ListViewController class. All UITableViewControllers have a tableView property that holds the actual UITableView.

Answer 3

Try to remove this line from ListViewController.h
#property (nonatomic, retain) UITableView *tableView;
Then replace your - (void) viewDidLoad in ListViewController.m by this code:
- (void) viewDidLoad
{
[super viewDidLoad];
[self.tableView setDelegate: self];
[self.tableView setDataSource:self];
}