NSPredicate custom object pointer - objective-c

Question

I have interfaces like:
#interface Isle
#property (nonatomic, strong) id index_one; //has to be an id ={
#property (nonatomic, strong) id index_two;
#end
#interface Item
#property (nonatomic, strong) NSString* name; //has to be an NSString
#end
Then I instantiate a search view controller:
#import "TableViewController.h"
#import "Isle.h"
#import "Item.h"
#interface TableViewController () <UISearchBarDelegate, UISearchDisplayDelegate>
#property (nonatomic, strong) NSArray* isles;
#property (nonatomic, strong) NSArray* filter;
#end
#implementation TableViewController
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self)
{
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
Isle* isle_one = [[Isle alloc] init];
Isle* isle_two = [[Isle alloc] init];
Isle* isle_three = [[Isle alloc] init];
isle_one.index_one = [[Item alloc] init];
isle_one.index_two = [[Item alloc] init];
isle_two.index_one = [[Item alloc] init];
isle_two.index_two = [[Item alloc] init];
isle_three.index_one = [[Item alloc] init];
isle_three.index_two = [[Item alloc] init];
((Item*)isle_one.index_one).name = #"ketchup";
((Item*)isle_one.index_two).name = #"hot sauce";
((Item*)isle_two.index_one).name = #"butter";
((Item*)isle_two.index_two).name = #"cheese";
((Item*)isle_three.index_one).name = #"cereal";
((Item*)isle_three.index_two).name = #"rice";
_isles = [[NSArray alloc] initWithObjects: isle_one, isle_two, isle_three, nil];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
- (void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope
{
NSPredicate* res = [NSPredicate predicateWithFormat:#"(index_one.name contains[cd] %#) OR (index_two.name contains[cd] %#)", #"ketchup", #"hot sauce"];
_filter = [self.isles filteredArrayUsingPredicate: res];
}
-(BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
[self filterContentForSearchText:searchString scope:[[self.searchDisplayController.searchBar scopeButtonTitles] objectAtIndex:[self.searchDisplayController.searchBar selectedScopeButtonIndex]]];
return YES;
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (tableView == self.searchDisplayController.searchResultsTableView)
{
return [[self filter] count];
}
return [[self isles] count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:#"CellID" forIndexPath:indexPath];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"CellID"];
}
if (tableView == self.searchDisplayController.searchResultsTableView)
{
Isle* isle = (Isle*)[self.filter objectAtIndex: indexPath.row];
NSString* str = [NSString stringWithFormat:#"%#\t\t%#", ((Item*)isle.index_one).name, ((Item*)isle.index_two).name];
cell.textLabel.text = str;
return cell;
}
Isle* isle = (Isle*)[self.isles objectAtIndex: indexPath.row];
NSString* str = [NSString stringWithFormat:#"%# %#", ((Item*)isle.index_one).name, ((Item*)isle.index_two).name];
cell.textLabel.text = str;
return cell;
}
#end
But it says that it is not key-value compliant. Any ideas how I can accomplish this?
EDIT:
My exact error is:
Project1[1688:60b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<NSSymbolicExpression 0x10e60a650> valueForUndefinedKey:]: this class is not key value coding-compliant for the key name.'
For filtering I did:
[arr filteredArrayUsingPredicate: res];