Trying to solve a [DetailViewController setDataController:]: unrecognized selector sent to instance - objective-c

Question

I have an Xcode Universal Storyboard project that is properly displaying data for the iPhone but does not display data for the iPad. I had initialized the data array using the code below.
It is working properly in the iPhone but does not display data in the iPad and gets the error:
-[DetailViewController setDataController:]: unrecognized selector sent to instance
This is the AppDelegate.m
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
UISplitViewController *splitViewController = (UISplitViewController *)self.window.rootViewController;
UINavigationController *navigationController = [splitViewController.viewControllers lastObject];
MasterViewController *masterViewController = (MasterViewController *)[navigationController topViewController];
DataController *controller = [[DataController alloc] init];
masterViewController.dataController = controller;
splitViewController.delegate = (id)navigationController.topViewController;
} else {
// Create the data controller and pass it to the master view controller.
UINavigationController *navigationController = (UINavigationController *)self.window.rootViewController;
MasterViewController *masterViewController = (MasterViewController *) [navigationController topViewController];
DataController *controller = [[DataController alloc] init];
masterViewController.dataController = controller;
}
The compiler is complaining about the DetailViewController here is that file.
#import "DetailViewController.h"
#import "Play.h"
#interface DetailViewController ()
#property (strong, nonatomic) UIPopoverController *masterPopoverController;
#end
#implementation DetailViewController
#synthesize masterPopoverController = _masterPopoverController;
#synthesize play;
#pragma mark -
#pragma mark View lifecycle
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
// Scroll the table view to the top before it appears
[self.tableView reloadData];
[self.tableView setContentOffset:CGPointZero animated:YES];
//self.part = play.part;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
} else {
return YES;
}
}
#pragma mark - Split view
- (void)splitViewController:(UISplitViewController *)splitController willHideViewController:(UITableViewController *)viewController withBarButtonItem:(UIBarButtonItem *)barButtonItem forPopoverController:(UIPopoverController *)popoverController
{
barButtonItem.title = NSLocalizedString(#"Trading Rules That Work", #"Trading Rules That Work");
[self.navigationItem setLeftBarButtonItem:barButtonItem animated:YES];
self.masterPopoverController = popoverController;
}
- (void)splitViewController:(UISplitViewController *)splitController willShowViewController:(UITableViewController *)viewController invalidatingBarButtonItem:(UIBarButtonItem *)barButtonItem
{
// Called when the view is shown again in the split view, invalidating the button and popover controller.
[self.navigationItem setLeftBarButtonItem:nil animated:YES];
self.masterPopoverController = nil;
}
#pragma mark -
#pragma mark Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// There are 2 sections, for rule, and media, in that order.
return 2;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
//The number of rows varies by section.
NSInteger rows = 0;
switch (section) {
case 0:
// For part and date there is just one row.
rows = 1;
break;
case 1:
// For the media section, there are as many rows as there are media.
rows = [play.media count];
break;
default:
break;
}
return rows;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"CellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
cell.autoresizingMask = UIViewAutoresizingFlexibleHeight;
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.textLabel.font = [UIFont boldSystemFontOfSize:11];
cell.textLabel.numberOfLines = 13;
}
NSString *cellText = nil;
switch (indexPath.section) {
case 0:
cellText = play.part;
break;
case 1:
cellText = [play.media objectAtIndex:indexPath.row];
break;
default:
break;
}
cell.textLabel.text = cellText;
return cell;
}
#pragma mark -
#pragma mark Section header titles
/*
HIG note: In this case, since the content of each section is obvious, there's probably no need to provide a title, but the code is useful for illustration.
*/
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
NSString *title = nil;
switch (section) {
case 0:
title = NSLocalizedString(#"Video Description", #"Part section title");
break;
case 1:
title = NSLocalizedString(#"Media", #"Main Media section title");
break;
default:
break;
}
return title;
}
#end

Answer 1

When you do
object.property = value;
in Objective-C code, that's a short cut for:
[object setProperty:value];
Since you don't appear to have a dataController property, there's no setDataController selector.
So either:
declare a dataController property in your DetailViewController's .h then synthesize it in your implementation, or
create a setter and manually assign it to an instance variable.

Answer 2

You are getting this error because in your iPad storyboard you do not have the class set properly for your navigation controller's rootViewController. Make sure the class for that viewController is set to DataController in the Identity Inspector. You probably have this set correctly in your iPhone version storyboard, which is why you don't get the error when running the iPhone version.