Question

I am trying to use custom UITableViewCells defined in IB where there are referencing outlets. I have successfully used the techniques shown in several places in stackoverflow to load and use UITableViewClass when there is no referencing outlet, like below.

NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"TheCellsClass" owner:nil options:nil];

I have a separate file called “TheCellsClass.xib”, which has a single UITableViewCell defined with a single UILable called Alabel, “IBOutlet UILabel *Alabel;”. If I connect the label to ALabel then I get this error

Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<NSObject 0x681b360> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key Alabel.'

After searching here and the web I understand that this is caused by the fact that “owner:nil” does not define a class with this object:Alabel. I cannot use “owner:self” because that is the UITableViewController, and also does not define “Alabel”.

I created a class called “TheCellsClass” as a sub class of “UITableViewCell” that does define Alabel, see below;

Then used:

        NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"TheCellsClass" owner:cell options:nil];

I still get the same error. So, can anyone point out the error of my ways? 🙂
I only way I can think to fix this is to remove all referencing outlets and connect
them using code

Subclass header :

#import <UIKit/UIKit.h>
@interface TheCellsClass : UITableViewCell {   
    IBOutlet UILabel *Alabel;    
}
@property (strong, nonatomic) UILabel *Alabel;
@end

Subclass body:

#import "TheCellsClass.h"
@implementation TheCellsClass
@synthesize Alabel;
@end

In the table view controller

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

I am using:

TheCellsClass* cell= [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (cell == nil) {
    if (cell == nil) {
        NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"TheCellsClass" owner:cell options:nil];

A zip of a sample project is here http://www.proaa.com/tryout.zip

Suggestions? Requests for more info?

Any help appreciated.
Geoff

Answer 1

Three things:

1. Remove TheCellClass from DetailViewController.xib

2. ALabel is linked to File’s Owner in TheCellsClass – link it instead to TheCellsClass in the Objects section. Also consider renaming ALabel – it is standard to name instance variables beginning with a lowercase letter.

3. In MasterViewController, change

   NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"TheCellsClass" owner:cell options:nil];
   

to

    NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"TheCellsClass" owner:nil options:nil];

After these three changes, your custom TableViewCell appeared in the simulator. Also consider renaming TheCellsClass to something that hints at what it’s subclassing, like MyCustomTableViewCell.