[Thinine]

I'm trying to do the challenge at the end of chapter 6 in Hillegass' book and need a little help. I'm trying to add an entry to a table view and can't figure out why it's not working. I know the interface is connected correctly and I've entered to code he gave me correctly, so I'm not sure where to go from there.

I've made connections between the buttons and their respective actions, as well as the table view and it's outlet. Is there anything else I need to do?

So, in general, how would I add an entry to a table view?

[Angus_D]

In general, you'd do whatever you need to do to its dataSource, then call -reloadData or -noteNumberOfRowsChanged.

[techtrucker]

Thinine,

Which edition of the book are you working with?

[techtrucker]

I looked at the first edition and chapter 6 is about Archiving, so I'm going to guess it's the second edition that you're using. Chapter 6 gets into the new Bindings and controller classes. The challenge I believe you're referring to is where he has you redo the application the "old way" without bindings and array controllers.
All I can say is that you need to double check all of your IB connections. Make sure the data source is specified, and that all the columns have the correct names. It's relatively easy to miss something along the way. Or, as Angus_D mentioned you could just not be reloading the table.
I worked through the same project back when the first edition of the book came out. I found the project and zipped it up for you if you'd like to take a look at it:

http://homepage.mac.com/stevewoodward/FileSharing4.html

If you need it in an earlier format (it's updated to XCode) let me know.

Steve W

Have you checked the web site?

Go here and type the page number in the form:

http://www.bignerdranch.com/products/cocoa1.shtml

[Thinine]

Yes, it is the second edition of the book and yes, it's redoing the RaiseMan application without using bindings. I've entered the code given in the book (added a few NSLog's to make sure my interface was working) but I can't seem to make new entries in the table view after clicking the Add Person button. I've checked out the BNR site and looked around cocoadev and from what I see, I've implemented everything I need to. But I can't seem to create new entries in the tableView. Should the code he gives us work, or do I need to add something? If I need to add something, can I get a hint at least?

MyDocument.h

Code:
#import <Cocoa/Cocoa.h>

@interface MyDocument : NSDocument
{
	NSMutableArray *employees;
	IBOutlet NSTableView *tableView;
}
- (IBAction)createEmployee:(id)sender;
- (IBAction)deleteSelectedEmployees:(id)sender;
@end

MyDocument.m

Code:
#import "MyDocument.h"
#import "Person.h"

@implementation MyDocument

- (id)init
{
    [super init];
    employees = [[NSMutableArray alloc] init];
    return self;
}

//Action Methods

- (IBAction)deleteSelectedEmployees:(id)sender
{
	NSIndexSet *rows = [tableView selectedRowIndexes];
	if ([rows count] > 0) {
		unsigned int row = [rows lastIndex];
		while (row != NSNotFound) {
			[employees removeObjectAtLastIndex:row];
			row = [rows indexLessThanIndex:row];
		}
		[tableView reloadData];
	}else {
		NSBeep();
	}
}

- (IBAction)createEmployee:(id)sender
{
	Person *newEmployee = [[Person alloc] init];
	[employees addObject:newEmployee];
	[newEmployee release];
	[tableView reloadData];
	NSLog(@"Tried to create employee");
	int rows = [tableView numberOfRows];
	NSLog(@"tableView has %d rows", rows);
}

- (int)numberOfRowsInTableView:(NSTableView *)aTableView
{
	return [employees count];
}

- (id)tableView:(NSTableView *)aTableView
		objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex
{
	NSString *identifier = [aTableColumn identifier];
	Person *person = [employees objectAtIndexRow:rowIndex];
	return [person valueForKey:identifier];
}

- (void)tableView:(NSTableView *)aTableView setObjectValue:(id)anObject forTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex
{
	NSString *identifier = [aTableColumn identifier];
	Person *person = [employees objectAtIndex:rowIndex];
	[person setValue:anObject forKey:identifier];
}


- (NSString *)windowNibName
{
    // Override returning the nib file name of the document
    // If you need to use a subclass of NSWindowController or if your document supports multiple NSWindowControllers, you should remove this method and override -makeWindowControllers instead.
    return @"MyDocument";
}

- (void)windowControllerDidLoadNib:(NSWindowController *) aController
{
    [super windowControllerDidLoadNib:aController];
    // Add any code here that needs to be executed once the windowController has loaded the document's window.
}

- (NSData *)dataRepresentationOfType:(NSString *)aType
{
    // Insert code here to write your document from the given data.  You can also choose to override -fileWrapperRepresentationOfType: or -writeToFile:ofType: instead.
    return nil;
}

- (BOOL)loadDataRepresentation:(NSData *)data ofType:(NSString *)aType
{
    // Insert code here to read your document from the given data.  You can also choose to override -loadFileWrapperRepresentation:ofType: or -readFromFile:ofType: instead.
    return YES;
}

@end

[techtrucker]

I'm not at home right now, but I am pretty sure he points you in the right direction but doesn't give you 100% of the code...

[techtrucker]

Try putting a call to [self createEmployee] in init and see how many rows get logged...

[Thinine]

Nope, doing that breaks the app entirely (selector not recognized error at run time). I think my problem is that I'm never actually adding a row to tableView. The log statement in my code shows that size never increases, while the employees array does, as evidenced by another log statement (not in the code above). So obviously I'm missing something when it comes to adding a row to tableView, and I can't figure out what that is.

[techtrucker]

I'm thinking it's a missing connection in IB. Make sure your connection to the table is to the table view, not the scroll view (that one bit me in the beginning). If you like send the project over to me and I'll see if I can figure it out.

stevewood66 at comcast dot net

[Thinine]

Nope, it's all connected right. That's the first thing I checked. My project is available here. Finder-zipped archive.

[Ambit]

Hello,

I'm new to Cocoa and have only just started the Hillegass book myself, after going through Kochan's excellent book on Objective-C, so please feel free to tell me to shut up and leave the replies to people who know what they're talking about. However, I was just wondering about this segment of code in createEmployee:

Person *newEmployee = [[Person alloc] init];
[employees addObject:newEmployee];
[newEmployee release];
[tableView reloadData];

There is no data in the object you have added to the array, so I was wondering if this could be the problem (ie. although the object gets added to the array, the table view hasn't got anything to display). Just as a test, have you tried hard coding the instance variables for newEmployee before adding it to the employees array?

Like I say, I am probably waaaay off the mark here, but I was interested in your post because I'm going to be facing the same challenge myself in a couple of days. Feel free to ignore this completely.

Cheers,
KB

[techtrucker]

Ambit,

In this case the book is having you set initial values in the init method of the Person class, as in:

- (id)init
{
[super init];
[self setExpectedRaise:5.0];
[self setPersonName:@"New Person"];
return self;
}

So each new Person you create starts out with those values.


Thinine,

I took a brief look at your project and so far I can't tell what's missing. I did verify that the array was being added to...later on when I'm back home I'm going to dig into it deeper.

Steve W

[Chuckit]

The immediate problem you're seeing is in your nib. You have a second, useless instance of MyDocument alongside File's Owner. The tableview is using File's Owner as its data source (as it should be), but the two buttons are connected to the phantom instance, and the tableView outlet in File's Owner isn't connected to anything at all.

However, the app still won't work quite right after you fix this. That part should be pretty easy, though. I recommend you look at your error messages.

[Thinine]

Yep, that was it. I knew it was something stupid, just not how stupid it was. Thanks.

techtrucker, thanks for trying and sorry to waste your time.

[techtrucker]

No problem at all, I just wish I had discovered the problem first! I got bogged down yesterday in a web site design gone wrong...anyone here good with ImageReady and PSD web templates?
At any rate, I should have noticed the instance of MyDocument which was not needed. I'll use the lame excuse that I haven't done a document based app in a couple of years.

Steve W

[wataru]

I just went through this challenge, not realizing that the code he gives you on page 136-7 basically does everything for you except sorting and disabling the Delete button. The challenge is way too easy if you copy his code, but he says it's "to get you started," and at this point we haven't learned about NSIndexSet. So what gives?

[PBG4 User]

Originally Posted by techtrucker

Try putting a call to [self createEmployee] in init and see how many rows get logged...

This call should probably be [self createEmployee:self] as the method is looking for a sender object.

[Chuckit]

Er…the problem was solved, like, a year ago. Wataru revived it to ask why the challenge is so pointless. (I don't know. I never used the Hillegass book.)

[PBG4 User]

Originally Posted by Chuckit

Er…the problem was solved, like, a year ago. Wataru revived it to ask why the challenge is so pointless. (I don't know. I never used the Hillegass book.)

Silly me, I just looked at the date/time stamp on the post previous to mine.

My correction still stands though and just might help someone who digs up this thread in a search next year.

[Chuckit]

True 'nuff.