Populating iOS table from Array - ios

Question

I have an array _locations which is populated from a server through a json query. I now want this array to populate a table that I have created, however it does not and it quits on [self.delegate itemsDownLoaded:_locations];.
If I look in the log I can see that _locations does get populated however, but it does not parse on that data.
Here is the full code for HomeModel2:
#import "HomeModel2.h"
#import "Location2.h"
#interface HomeModel2(){
NSMutableData *_downloadedData;
}
#end
#implementation HomeModel2
- (void) downLoadItems{
// Download the json file
NSURL *jsonFileUrl = [NSURL URLWithString:#"http://server.com/service_2.php"];
// Create the request
NSURLRequest *urlRequest = [[NSURLRequest alloc] initWithURL:jsonFileUrl];
// Create the NSURLConnection
[NSURLConnection connectionWithRequest:urlRequest delegate:self];
}
#pragma mark NSURLConnectionDataProtocol Methods
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
// Initialize the data object
_downloadedData = [[NSMutableData alloc] init];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
// Append the newly downloaded data
[_downloadedData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
// Create an array to store the locations
NSMutableArray *_locations = [[NSMutableArray alloc] init];
// Parse the JSON that came in
NSError *error;
NSArray *jsonArray = [NSJSONSerialization JSONObjectWithData:_downloadedData options:NSJSONReadingAllowFragments error:&error];
// Loop through Json objects, create question objects and add them to our questions array
for (int i = 0; i < jsonArray.count; i++)
{
NSDictionary *jsonElement = jsonArray[i];
// Create a new location object and set its props to JsonElement properties
Location2 *newLocation = [[Location2 alloc] init];
newLocation.name = jsonElement[#"Name"];
newLocation.address = jsonElement[#"Address"];
newLocation.latitude = jsonElement[#"Latitude"];
newLocation.longitude = jsonElement[#"Longitude"];
// Add this question to the locations array
[_locations addObject:newLocation];
}
// Ready to notify delegate that data is ready and pass back items
if (self.delegate)
{
[self.delegate itemsDownLoaded:_locations];
}
}
#end
.. and this is the ViewController to publish the data:
#import "ViewController.h"
#import "Location2.h"
#interface ViewController (){
HomeModel2 *_homeModel;
NSArray *_feedItems;
}
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Set this view controller object as the delegate and data source for the table view
self.listTableView.delegate = self;
self.listTableView.dataSource = self;
// Create array object and assign it to _feedItems variable
_feedItems = [[NSArray alloc] init];
// Create new HomeModel2 object and assign it to _homeModel variable
_homeModel = [[HomeModel2 alloc] init];
// Set this view controller object as the delegate for the home model object
_homeModel.delegate = self;
// Call the download items method of the home model object
[_homeModel downLoadItems];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)itemsDownLoaded:(NSArray *)items
{
// This delegate method will get called when the items are finished downloading
// Set the downloaded items to the array
_feedItems = items;
// Reload the table view
[self.listTableView reloadData];
}
#pragma mark Table View Delegate Methods
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of feed items (initially 0)
return _feedItems.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
// Retrieve cell
NSString *cellIdentifier = #"BasicCell";
UITableViewCell *myCell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
// Get the location to be shown
Location2 *item = _feedItems[indexPath.row];
// Get references to labels of cell
myCell.textLabel.text = item.address;
return myCell;
}
#end

Answer 1

Can you confirm that there is "location" objects after this piece of code:
// Set the downloaded items to the array
_feedItems = items;
or is the delegate method not even called?
i don't understand your wording...

Answer 2

I found the problem. I thick it all has to do with the delegate.self method. I read that using this in several places in your code is not the best thing and that the references easily can get messed up if you update and compile frequently. So i flushed all my old compiled data, and ran the app again from scratch and it worked!

Answer 3

I don't believe you ever define the delegate property, or a protocol for the delegate.
As such, you have no way of ensuring the view controller responds to the methods defined in the delegates protocol.
Can you see if the delegate method in the view controller ever gets called?

Answer 4

Instead of below code
if (self.delegate)
{
[self.delegate itemsDownLoaded:_locations];
}
Use
// Set the downloaded items to the array
_feedItems = [NSArray arrayWithArray:items];
// Reload the table view
[self.listTableView reloadData];
Or Change this line of code and check
Instead of
_feedItems = items;
Use
_feedItems = [NSArray arrayWithArray:items];
Hope it helps you...!