My tableView is showing up but its empty? How to fix?

Question

I am creating a rss feed app and my Main view controller will display the feeds. My app first did not have any errors and performed well. Recently, I added a navigation menu as shown here: http://www.appcoda.com/ios-programming-sidebar-navigation-menu/ Now the navigation menu is not my problem. My rss feed listview is completely empty and it is displaying empty cells. here is my Main view controller.h :

#import <UIKit/UIKit.h>

@interface MainViewController : UIViewController <NSXMLParserDelegate>

@property (weak, nonatomic) IBOutlet UIBarButtonItem *sidebarButton;
@property (strong, nonatomic) IBOutlet UITableView *tableView;

@end

And here is my Main View Controller.m :

#import "MainViewController.h"
#import "SWRevealViewController.h"
#import "DetailViewController.h"

@interface MainViewController () {

    NSXMLParser *parser;
    NSMutableArray *feeds;
    NSMutableDictionary *item;
    NSMutableString *title;
    NSMutableString *link;
    NSString *element;

}

@end

@implementation MainViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    feeds = [[NSMutableArray alloc] init];
    NSURL *url = [NSURL URLWithString:@"http://images.apple.com/main/rss/hotnews/hotnews.rss"];
    parser = [[NSXMLParser alloc] initWithContentsOfURL:url];
    [parser setDelegate:self];
    [parser setShouldResolveExternalEntities:NO];
    [parser parse];

    // Change button color
    _sidebarButton.tintColor = [UIColor colorWithWhite:0.1f alpha:0.9f];

    // Set the side bar button action. When it's tapped, it'll show up the sidebar.
    _sidebarButton.target = self.revealViewController;
    _sidebarButton.action = @selector(revealToggle:);

    // Set the gesture
    [self.view addGestureRecognizer:self.revealViewController.panGestureRecognizer];

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table View

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return feeds.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];
    cell.textLabel.text = [[feeds objectAtIndex:indexPath.row] objectForKey: @"title"];
    return cell;
}

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict {

    element = elementName;

    if ([element isEqualToString:@"item"]) {

        item    = [[NSMutableDictionary alloc] init];
        title   = [[NSMutableString alloc] init];
        link    = [[NSMutableString alloc] init];

    }

}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {

    if ([elementName isEqualToString:@"item"]) {

        [item setObject:title forKey:@"title"];
        [item setObject:link forKey:@"link"];

        [feeds addObject:[item copy]];

    }

}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {

    if ([element isEqualToString:@"title"]) {
        [title appendString:string];
    } else if ([element isEqualToString:@"link"]) {
        [link appendString:string];
    }

}

- (void)parserDidEndDocument:(NSXMLParser *)parser {

    [self.tableView reloadData];

}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([[segue identifier] isEqualToString:@"showDetail"]) {

        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
        NSString *string = [feeds[indexPath.row] objectForKey: @"link"];
        [[segue destinationViewController] setUrl:string];

    }
}

@end

Thanks for any help!

Answer 1

You might want to setup breakpoints at the following spots:

• didStartElement: to check if the parsing started
• parserDidEndDocument: to check if the parsing finished and reloaded the tableview
• tableView: numberOfRowsInSection:to check if the tableview delegate methods are being hit

You also want to check if the tableView outlet, as well as the delegate and datasource, are setup correctly in Interface Builder