Pass parameter when initializing table

Okay, I'm totally stumped here.

This works in CouponListViewController.m:

- (void)viewWillAppear:(BOOL)animated {
     [super viewWillAppear:animated];
     self.couponList = [CouponDatabase database].couponList;
     self.title = @"Coupon List";
}

And this works in CouponDetailViewController.m:

- (void)viewWillAppear:(BOOL)animated {
    CouponDetails *details = [[CouponDatabase database] couponDetails:_uniqueId];
    if (details != nil) {
        [_merchantNameLabel setText:details.merchantName];
        [_longDealLine1Label setText:details.longDealLine1];
        //....blah...blah//
    }
}

But when I change the CouponDatabase.h from this (which works with the above):

@class CouponDetails;

@interface CouponDatabase : NSObject {
    sqlite3 *_database;
}

+ (CouponDatabase *)database;
- (NSArray *)couponList;
- (CouponDetails *)couponDetails:(int) uniqueId;

...to this (which works if I manually set the value of 'selectedCategory' inside the method):

@class CouponList;
@class CouponDetails;

@interface CouponDatabase : NSObject {
    sqlite3 *_database;
}

+ (CouponDatabase *)database;
- (CouponList *)couponList:(int) selectedCategory;
- (CouponDetails *)couponDetails:(int) uniqueId;

and then change CouponListViewController开发者_如何学Python.m to this:

1    - (void)viewWillAppear:(BOOL)animated {
2       [super viewWillAppear:animated];
3       self.couponList = [[CouponDatabase database] couponList:_selectedCategory];
4       self.title = @"Coupon List";
5    }

I get this error on line 3 above:

warning: incompatible Objective-C types 'struct CouponList *', 
expected 'struct NSArray *' when passing argument 1 of 'setCouponList:' 
from distinct Objective-C type

Question: What is the proper formatting of the 'self.couponlist' line so that I can pass an integer to the CouponDatabase for use in the couponList method?

EDIT: I'm aware that couponDetails is now a class instead of an array - I just don't know know how to format the line to initialize the table data.

I hope this makes sense - any help on this would be very greatly appreciated.

Thanks in advance!

Adding CouponListViewController.h:

#import <UIKit/UIKit.h>

@class CouponDetailsViewController;

@interface CouponListViewController : UITableViewController {

    NSArray *_couponList;
    CouponDetailsViewController *_couponDetails;
    int _selectedCategory;
 }

@property (nonatomic, retain) NSArray *couponList;
@property (nonatomic, retain) CouponDetailsViewController *couponDetails;
@property(nonatomic, assign) int selectedCategory;

@end

Try changing your CouponListViewController.h to this:

#import <UIKit/UIKit.h>

@class CouponDetailsViewController;

@interface CouponListViewController : UITableViewController {

    CouponList *_couponList;
    CouponDetailsViewController *_couponDetails;
    int _selectedCategory;
 }

@property (nonatomic, retain) CouponList *couponList;
@property (nonatomic, retain) CouponDetailsViewController *couponDetails;
@property(nonatomic, assign) int selectedCategory;

@end

Oops I put my response in my own original post and should have put it here:

Edit: Okay, I made changes to CouponListViewController.h as recommended by Robert, plus added @class CouponList; as follows:

#import <UIKit/UIKit.h>

@class CouponList;
@class CouponDetailsViewController;

@interface CouponListViewController : UITableViewController {

    CouponList *_couponList;
    CouponDetailsViewController *_couponDetails;
    int _selectedCategory;
}

@property (nonatomic, retain) CouponList *couponList;
@property (nonatomic, retain) CouponDetailsViewController *couponDetails;
@property(nonatomic, assign) int selectedCategory;

@end

I'm still getting errors in CouponListViewController.m:

#import "CouponListViewController.h"
#import "CouponDatabase.h"
#import "CouponList.h"
#import "CouponDetailsViewController.h"

@implementation CouponListViewController
@synthesize couponList = _couponList;
@synthesize couponDetails = _couponDetails;
@synthesize selectedCategory = _selectedCategory;

 - (void)viewWillAppear:(BOOL)animated {

     [super viewWillAppear:animated];
     self.couponList = [CouponDatabase database].couponList; // <--- ERROR 1
     self.title = @"Coupon List";
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [_couponList count]; //  <--- WARNINGS 1 AND 2
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    if (self.couponDetails == nil) {
        self.couponDetails = [[[CouponDetailsViewController alloc] initWithNibName:@"CouponDetailsViewController" bundle:nil] autorelease];        
    }
    CouponList *info = [_couponList objectAtIndex:indexPath.row];  // <--- WARNING 3
    NSLog(@"%@", info.uniqueId);
    _couponDetails.uniqueId = info.uniqueId;
    [self.navigationController pushViewController:_couponDetails animated:YES];
}

ERROR 1: request for member 'couponList' in something not a structure or union

WARNING 1: 'CouponList' may not respond to '-count'

WARNING 2: return makes integer from pointer without a cast

WARNING 3: 'CouponList' may not respond to '-objectAtIndex:'

In you original code for CouponDatabase, you are changing the definition:

- (NSArray *)couponList;

for this one:

- (CouponList *)couponList:(int) selectedCategory;

Nevertheless, you use that return value as datasource for a list view controller, so . Here you have a mismatch you should fix. How to fix it depends on the semantics of your application. What are your trying to do with - (CouponList *)couponList:(int) selectedCategory;? What does really return this selector? What is the interface CouponList? Possibly you should change the line:

 self.couponList = [[CouponDatabase database] couponList:_selectedCategory];

so that it returns an NSArray build from a CouponList. But I am not sure of the semantics of your objects, so this might not be the case.