Historical errata for Beginning Mac Programming

Launching IB on my system, Tools->Library, does not show the as shown in Fig 2.6 “Interface Builder Library Palette” You don’t tell us how to get the IB to show the icon view. In my case for IB, all I see is a folder hierarchy

Creating an Instance of our Notifying Class, 2nd para:
“Give our knowledge so far” should be “Given our knowledge so far”

Figure 3.3 shows the project window under Mac OS X “Leopard” and Xcode 3.1; if you create this project under Snow Leopard and Xcode 3.2, you will also see TextAppAppDelegate.h and .m files in the Classes group. This has been fixed for the next Beta.

Figure 2.4 has seven icons. When I follow your instructions, I get six. The one that is missing is “Text App App…” (Using Xcode 3.1.3).

Final sentence on the page reads “We can now redefine our House class as simply being a subclass of the Building class; put another way, it inherits from the House class:”. Should be “We can now redefine our House class as simply being a subclass of the Building class; put another way, it inherits from the Building class:”.

“Initializing Strings”
First sentence states “…we find are various routes”

Should this be “…we find there are various routes”

Maybe this is somewhere in the book which I have yet to read, but a chart showing the various %i, %f, etc for NSString initWithFormat would be very helpful. You are doing a great job of explaining them as we go along, but a full chart showing them all with a short (3-4 word) description on each would be great.

Last paragraph of the page " I still have the odd con- fusion when I use an elevator over in the U.s. In the U.K., "

U.S. should be capitalized.

showSomeText: should be displaySomeText: near the top of the page. First new paragraph of the page on the third line.

error:(NSError )outError

too many *

Second paragraph (beginning with “NSDocument responds”) does not word wrap properly on the code sample

Hopefully you’ve recovered from looking at so many logical expressions and operators, such as ==, && and ||

Bold on the pipes.

last sentence “display information on screen, and controllers that liase between model objects and views.”

Did you mean liaise?

in line 6, the reference to “Build & Go” should read “Builid & Run”, as this is the name of the tool in XCode for Snow Leopard.

In Snow Leopard, the “Build & Go” button is actually called “Build & Run”.

The “Build & Go” button is called “Build & Run” in Snow Leopard.

Missing the end of a sentence:

“Guidelines for maximum and minimum values that you can use in a particular variable type can be found in .”

I’m guessing a header file is what is meant?

11th line reads: “Make your NotifyingObject.h file look like this:” but I believe it should be “Make your NotifyingClass.h file look like this:” (NotifyingClass.h not NotifyingObject.h).

“Go back to the MainMenu.xib file in Interface Builder and use the object list view”

This should be MyDocument.xib

End of third line from bottom:
Don’t despair—we’ll see how to implement these methods in thechapter

end must be “…the chapter..”

Last paragraph “..as we’ll see inthe chapter on Mac OS X…”

Space between in and the

You appear to have mixed up the slash characters when describing the notation for a newline, ‘\
’. A forward slash is ‘/’ and a backslash is ‘\\’.

Should the format specifier for an integer value not be %i in the following code…

[textView insertText:[NSString stringWithFormat:@“value of pointerToAnInt is: %p\
”,
pointerToAnInt]];

Communication Between Xcode and Interface Builder
Remember how we created an object instance in Interface Builder (that
blue cube thing) in the last chapter, and set its class to “NotifyingObject” or “NotifyingClass” ?

Change “window, you’ll see a message appear each time in the ‘debugger’ console
window.” to "window, you’ll see a message appear each time in the ‘XCode - Run - Console’
window.
I spent some time trying XCode’s Debugger, MiniDebugger and Debugger Display.

Change “Interface Builder to edit the MainMenu.xib file.” to “Interface Builder to alter the MainMenu.xib window”

I currently unable to connect the “outlets” group to “Text View”, but will get back to you why, when I find out!

Am able to connect “outlets” group to “Text View”, I think my problem was text I had saved in the “Text View” similar to “Lorum Ipsum” ? I don’t really know, I just deleted the project and started again.

On trying to Build and Run at this stage, a warning is issued against the newly introduced ‘dealloc’ method of the WonderfulNumber class, viz “Method possibly missing a [super dealloc] call”. This may be intentional at this point but should be explained.

“We’ll look at the exact syntax for this ina future chapter; for now, it’s a variant of something like this:
NSString *myKeyName = @”myKeyName“;”

There’s ‘ina’ there, which of course is meant to be ‘in a’. This is near the bottom of the page.

The line…

[textView insertText:stringToOutput];

prior to the declaration…

int indexOfObject = [shoppingListArray indexOfObject:secondObject];

is missing and hence the outcome will not be as shown.

“For an NSArray to be able to archive its contents, it requires that every object within the array conform to something called the NSCoding protocol.” The text in B3.0 is misleading, implying that the writeToFile:… method requires stored objects to implement the NSCoding protocol. In fact, the writeToFile:… method requires that every object in the array be an NSString, NSData, NSArray, or NSDictionary—it has nothing to do with NSCoding. In order to write the array of shopping list items to disc, we will have to use a different technique (which does have everything to do with NSCoding).

Immediately prior to the “Adding New Items” heading, the application will not work as described at this stage because there has been no mention that the Add push button has to be linked to the File’s Owner and the addNewItemToShoppingList method.

Please amend my submitted erratum for page 173 to be for page 174 and substitute the context to be immediately before “Editing the Items”. The rest of the entry is correct.

Formatting of the paragraph (below) needs adjustment because the tableView part flows off the page instead of either wrapping or starting on a new line.

NSDocument responds to the updateChangeCount: message—you would need to insert a call to this method, passing it a constant value of “NSChangeDone,” in both the addNewItemToShoppingList: and tableView:setObjectValue:forTableColum to solve this problem.

Hi, I don’t think this line is correct:

Notice also that we’ve added the characters “\
” (that’s a forward-slash, not the more frequently used back-slash) on the end of the string.

- (IBAction)removeItemFromShoppingList(id)sender

should be

- (IBAction)removeItemFromShoppingList:(id)sender

we must to decide how best to

too much tos

- (IBAction)removeItemFromShoppingList(id)sender

seems to be a copy and paste error. have a look on all occurences of removeItemFromShoppingList

While working with “Programming cocoa with ruby” it was all about the event-system of an os-x application. Will this be a part of the not yet written chapters?
I would also like to see some Infromation along the way how one can use XCode features like refactoring and stuff like that.
And at least a little example of how to write a test is a must for any pragmatic reader!

There is the same ‘ina’ on the next page with duplicate text from above.

inthe should be in the

if( self = [super init] )

this idiom should be explained.

as well as the really important retain in itemName = [newName retain];

you might show what happens if retain is missing, so one sees the memory in the table cell

When running the wonderfulNumberWithFloat method, the console outputs the following error: “+[WonderfulNumber wonderfulNumberWithFloat:]: unrecognized selector sent to class 0x40c0”

The code looks like it should be correct, but apparently not.

Perhaps my previous erratum wasn’t correct. I still had [myWonderfulNumber release]; from a prior example immediately after the previously mentioned code. Removing it seemed to fix my problem. Maybe there should be an explanation as to why that shouldn’t be there. (Is it because we aren’t specifically calling [WonderfulNumber alloc] from within displaySomeText, as on page 136?)

5.1 How Memory Works
Your computer contains various different physical storage places for
information.

It seems to me that “various different” repeats repetitiously :)

When I implemented initWithFormat and use the @“%f”, there is no line break? Maybe I missed it, but it looks to just print the number (pi) multiple times on the same line in the text window? Not a big deal, but I was looking at the output of multiple clicks to see the alloc/dealloc, etc.

newItemTextField s/b newItemNameTextField 3x

so let’s use the same technique here and
change the method to this:
- (IBAction)addNewItem:(id)sender

* s/b
so let’s use the same technique here and
change the method to this:
- (IBAction)addNewItemToShoppingList:(id)sender

After reading the first chapters of “Cocoa Programming for Mac OS X”, I think that this book covers legacy technology. All the information about memory, allocating and pointers is nothing that a newbee is interested in. Especially if there is such a thing like a garbege collector…

NotifyingClass does not exist in the newest version of Interface Builder (Version 3.2.1 (740)) and it will not let you change the ObjectID to 541 shown on the following page.

In addition the library pane in 3.5 does not look at all like the current version

“that each of those lines starts with two backslash charac- ters, like this:
// TextApp”

should be:
“that each of those lines starts with two slash charac- ters, like this:
// TextApp”

Backslashes go like this: \\\\

Hope this helps. Lovin the book so far,
…/j

Working with Colors… 2nd paragraph reads:
“… working with an earger” Should be “eager”

“If you try changing the content view outlet” -> mainView outlet.

“Guidelines for maximum and minimum values that you can use in a particular variable type can be found in .”

Found in…?

‘After the colon comes something in brackets with an asterisk “(HouseObject *)”’

Brackets or parentheses?

Figure 4.2 displays the button before it is created (in the paragraph immediately following)

I think it might be better to save the actual explanation of pointers for a later point in the book.

Suggest tight pairing of the figures on pages 68-69. Specifically, if the connection drag isn’t done to the TOPMOST area of the Text View it won’t have an effect; this would be more obvious to me if the graphic were right there.

‘Notice that there are no normal brackets “(” or “)” in use here’

Another brackets versus parentheses situation.

In section 1.3 you indicate you are running version 3.2 of XCode and then in pages 22 and 23 you indicate that in earlier versions of XCode there are problems with pList and other naming. I am running version 3.2.1 and I see the same issues, so either the footnotes are wrong and it’s not just earlier or you are running a new version then 3.2

In footnote no.2: “…it’s the incredibly long value
11111111111111111111111111001110. Next, try converting the number 50 into binary; it’s the
more manageable 110010. That really long number has those six bits on the end…” This long number end is not the same as 110010, it is 001110, or i am missing the point?

co-ordinates

shouldn’t this just be coordinates?

From the Tools menu, open up the Library panel. This panel, …

Then, 1st line next paragraph —> the Library panel is referred to as the library palette

Drag out a text view object from the Library palette (as in my last post, Library palette vs Library panel)

“Drag out a text view object from the Library palette” … This is the first time an “object” has been referenced as something that a new programmer has to manipulate. It might not be clear what a text view object is (the first time). Maybe … click on the object “Text View” in the Library panel and drag it on to the TextApp Window and let go. This adds a Text View object into our TextApp application’s window. We can use this Text View … or something

Once the basic layout of the application is agreed,

Once the basic layout of the application is agreed upon, … or
Once the basic layout of the application is acceptable,

From Chapter 2: “Even when you’re eventually allowed to do something at your computer, it’s writing code for little command-line tools that output text to a “no user interface” console screen. This book is different."

Yet this is exactly what has been done by the end of Chapter 3.

NSString *numberString …

We don’t explicitly set up this string with alloc and init like we did with *stringToReturn (above). Is the memory used by *numberString automatically alloced and inited? Is the memory also automatically dealloced?

The sentence that reads, “Click once again on the Build and Go toolbar item to launch your application.”: Shouldn’t this be “Build and Run” instead?

There are many different types of collections … arrays being one of them.

There are also dictionaries, sets … these are collections too.

Switch over to Interface Builder and set the action for the New Item text field to be the addNewItemToShoppingList: method. You’ll need to right-click on the text field and set the selector to the File’s Owner object’s addNewItem- ToShoppingList: action method.

I do not understand these directions.

This expression will be true only if firstValue is less thansecondValue.
s/b
This expression will be true only if firstValue is less than secondValue.

for( currentIndex = 0; currentIndex < [monthsArray count]; currentIndex )

Is [monthsArray count] executed for each item in the array?

Using our multi-story building analogy … You bring this up but then don’t follow through with the analogy, using array constructs instead.

Using our shopping list model, shoppingListArray stores one string (the item’s name) for each position of the array. We have already written code to access, change and display these individual strings.

We need to store more than just the item’s name. Our immediate need is to add a quantity for each item in our list. In the future, we may need to add even more information like size, flavour, the last price we paid for the item, the store to buy it from, etc. It seems like we need an array to store all of this information about each shopping list item.

We can continue to use ShoppingListArray to store items in each position of the array, but instead of storing just the item’s name in a string at each position … we will store an array containing all of the data for each shopping list item. At first this “inner” array will contain a string for the item name in the first position and a number for the quantity in the second position. We can easily store more information for each item by adding them to the array.

We can move through our individual items in shoppingListArray like we have in the past but when we get to the item we need, we will now have to move through the second “inner” array to access the item’s name and quantity.

This means …

Awfully wordy but I hope the message is clear

Thanks for the quick follow up. I think the repeating method call is significant, especially if you are dealing with a restricted platform or a very large array. I am just learning Objective-C and have no C background. This book is for newbies like me … I need to learn how to write good code, now is the time to start thinking about these things.

“If you declare a pointer to an NSButton object” should be “If you declare a pointer to an object”, and “myButton” should be “someObject”

Incorrect method name passed into the selector argument:

[center addObserver:self selector:@selector(needToShowMeasurements:)
name:WVMeasurerShowMeasurementsNotification object:nil];

“needToShowMeasurements:” should be “handleShowMeasurements:”

instead using custom code to draw the the list,

You’ll need to synthesize the new property at the top of the interface declaration

should be implementation declaration

For our simple Windows and Views application, this doesn’t matter.

To avoid the awkward visual of the shift in window size (from the IB window definition vs the constrained window), constrain the window like:

frameSize.width = (frameSize.height * w / h);

where w is the Content Frame Width and h is the Content Frame Height
of the “Window and Views” window that is shown in IB’s Window Size inspector panel.

This allows you to smoothly expand and shrink the window from its original size.

NSNotificationCenter *center = [NSNotificationCenter defaultCenter];

The font should be in the style consistent with “text to be entered” not in the “blue” style used for text that already exists.

but that’s OK, because it’s only for internal use.7

I’m not so sure if this is ok technique or not … but I sure would recommend documenting the fact that this method is constrained in this manner.

Is this an Objective-C “feature” or a hangover from it’s C ancestry?

Just declare the method in the header file and you don’t have to muck around with positioning the methods or worrying about what happens when you compile new code that uses this method six months from now.

Am I missing something?

Other Cocoa Mechanisms, on the next pagebefore starting out.

page before

There are various reasons why this is useful, not least because it enables us to use Key-Value Observing (KVO), where one object can register to observe the the value held at a specific key in another object.

One of the reasons why this is useful is that it enables Key Value Observing (KVO). KVO is where one object …

You’ll remember that we had to write code in our Shopping List appli- cation to reload the relevant row in the table whenever a shopping list item was modified. There’s another Cocoa technology, Bindings, …

This functionality can be extended by incorporating Bindings, another Cocoa technology. Bindings makes it possible to automatically sync user interface values with application data in both directions.

Bindings, in conjunction with KVC & KVO, makes … all using IB.

If you review our Shopping List application, all the code relating to updating the views and instance variables (maybe show the code) could have been handled automatically, without code, using KVC, KVO and Bindings!!

Under Mac OS X 10.6 Snow Leopard, we have access to Grand Central Despatch (GCD) …

Grand Central Dispatch

Even though this book is titled Beginning Mac Programming, there’s so much overlap between what we’ve already learnt

I just learnt that learnt is the British equivalent of our learned.

Month 2 is Feburary should read Month 2 is February

[shoppingListTableView reloadData]; is missing at the end of the addNewItem- ToShoppingList: method

alert isn’t released in addNewItemToShoppingList: method

deleteItem: method doesn’t exist. It should be named removeItemFromShoppingList:

I believe the sentence “Open the new project’s MainMenu.xib in Interface Builder.” should read “Open the new project’s MyDocument.xib in Interface Builder.”

For some weird reason my Xcode (3.2 on OS X 10.6) won’t recognize NSWindowDelegate and build fails. This despite WVMeasurer.h including Cocoa/Cocoa.h, which in turns trickles down to AppKit/NSWindow.h, which does declare the delegate.

What gives?

Possible tech issue with the opening of a saved shopping list using NSKeyedUnarchiver. Although saving does produce a proper binary prop file, reloading it yields an EXC_BAD_ACCESS every time (opening right after launch, opening with no existing window, opening right after save, whatever). I can vouch for my code being what’s in the book, too.

Xcode 3.2 on OSX 10.6.

Ping me if you need any further info! (the Prags have my e-mail).

componentsJoinedByString should be componentsJoinedByString:

This paragraph re Id (sender) is important but fuzzy; a reader could miss the importance:

Returning to Target-Action, we stated a little earlier that a method needs to accept a single argument to work for Target-Action. This argu- ment happens to be used to identify the object that sent the message in the first place. When we connect up a button in TextApp to target our NotifyingClass instance, the button would send the message, and specify that it was the sender. The signature therefore needs to look something like this:
- (void)displaySomeText:(id)sender;

I missed it completely and was baffled until I re-read the page a couple of times.

Counters and Array Indices, 3rd paragraph.

And, because
the array index is zero-based, but the count method will return the…

Looks like but is a typo.

“8. Draw three different-colored circles for Close, Minimize, and Max- imize.”

The green widget represents ‘Zoom’, not Maximize (as it is in Windows)

It would be useful to get highlighted in red, in the code excerpt, the “%u” since it is changed form previous pages.
I just overlooked it since I didn’t read the paragraph after the example.

MINOR: It’s “Build and Run,” not “Build and Go”

“a number represented by the next 4 bits” should say “a number represented by the next 5 bits”.

This is in the paragraph at the bottom of the page.

“Since in binary we can use only two possible digits (0 and 1), we are going to be working with column headers that are multiples (or powers) of 2.”
This is confusing, multiples and powers are not the same thing. e.g. 6 and 14 are both multiples of 2, but not powers of 2.

Both versions of tibmac-code are empty. If no code samples are available, please indicate so on the download page. Thanks.

The highlighted code to replace reads
&& [textField intValue] 42 but the code which should be highlighted should be textField && [textField intValue] 42

Otherwise the code will read
generateTextButton && [textField intValue] == 42

The line which reads
writing “2 + 4 * 5” would be interpreted as “2 + 20” rather than “8 * 5”
should read
writing “2 + 4 * 5” would be interpreted as “2 + 20” rather than “6 * 5”

We’ll use Interface Builder again to set the delegate, so open the MyDoc- ument.xib file, and set the delegate for the table view to be the MyDocument object, just like you did the data source.

should be linked to File’s Owner, which is the case on p168 of the book for the data source.

An error, really. If, by chance, you have closed the TextApp window after the last run before this section, there is nothing to explain how to reopen it at this point when you need it again. Either that or somewhere back in the last section in which there is a build and run to produce the window it should be made clear that you shouldn’t close it. Now must go back and undo changes.

The following text: “You’ll also find that if you make changes to a saved document and select File > Revert to Saved, you’ll be asked whether you really want to lose your changes. If you click the Revert button, the application will load the preexisting data from the saved file.” is not true at the point where it is presented. That question is not asked unless you already coded the window to know whether it is dirty, as described in the following section.

At first I couldn’t get the HUD to connect. It wasn’t until I managed to get it to the top of the NSTextView that it connected. SOme additional clarity on this point would have been helpful, because it appears that the whole NSScrollView is the object called TextView, but only the top of the ScrollView is actually active.

Not an error per se, since both versions work, but a confusing inconsistency. On page 210 the version of addNewItemToShoppingList, now changed to clear the text field on enter only, there is no reference to an NSString object as there is in the initial addNewItemToShoppingList method on page 170. As I said both work but I’m not sure why there was a change although I can see how both work.

Hope I’m not just being too fussy.

Me again, sorry - this is an error. I hadn’t entered the code the way the book showed before. I had entered
[shoppingListArray addObject:[newItemNameTextField…] which did work. The code in the book is
[shoppingListArray addObject:[newItemTextField…] which brings up an undeclared error.

in the pseudo code section on Page 183 it reads “…otherwise if they the Cancel button…”

Should read “…otherwise if they click the Cancel button…”

In the paragraph that begins “Generally, you’ll see the relevant…” the last sentence “…, you can even place it all one the same line,…”

should read “…, you can even place it all on the same line,…”

I am not certain if this is done intentionally, however here (as well as page 256 of the PDF version and other places) in the init method, the code

“self = [super init]
if (self) {…”

is used when previously, the convention/recommendation of the book (see the last paragraph of page 209 in the PDF version) has been

“if (self = [super init]) { …”

I’m curious as to why the switch. Was this just an oversight?

Not a typo, just a function of the English language.

In the next to last paragraph on this page, “…to define a list of messages such a delegate object might implement.”

I read that paragraph at least a few times before I realized that the “such a delegate object” part was referencing the previous paragraph’s “It just so happens that we can provide NSTableView with a delegate object.”

There should be an explicit instruction to remove the [WonderfulNumber release]; at the end of the method.

In explaining decimal notation the book claims that: “…if you multiply the header of a column by the header of the column on its right (for example, multiplying 100 by 10), you end up with the column on its left (1,000).”
This is only correct for the example you gave. 10 x 1 is not 100 and 1000 x 100 is not 10 000.

In addition to #42802: I couldn’t get the HUD to connect either, and in my case, the view window was apparently placed to far upwards, so could not connect it. I had to reposition the window, and then I could link it.

I couldn’t figure out how to get the HUD to connect to NSTextView until I found this page and read #42802 by Michael Wallis.

In “The removal Instructions” para: add explanation that should be replaced by the location of the developer tools installation; usually /Developer

We need a way to set the value of our circumference variable to the value held inside the text field.

should be:

We need a way to set the value of our radius variable to the value held inside the text field.

Error was ‘circumference undeclared’ message when I did build and run.
To fix this, I went to the header file and put (float) line above (IBAction) line. Then it worked fine.

Before “Switch back to XCode” you should mention to save what you did in IB.

Last paragraph,
Last sentence,
Example is only valid if the base column header is 100.
JFB

Same problem, won’t compile.
Obviously a different version of Xcode is required to follow this book.
I wish the author would type the actual syntax instead of pointing me at the Xcode documentation. It’s hard to see the trees for the forest.

In the second paragraph from the bottom, the sentence begins ‘The <> in brackets before…’. Should it read the ‘The <> in parentheses before…’?

Not an error, but I got hung up for several days on the tableView method (on page 171) that enables you to edit the array items directly on the table.

I assumed that the code snippet on page 171 was meant to replace the existing tableView method! After downloading the code from this site I saw that you can have an (id)tableView and a (void)tableView in the same implementation - maybe just add a line of text that clears that up?

Otherwise the book is extremely valuable, and the best intro I’ve found so far - really enjoying working through it.

This is the first Mac programming book which I have used and would benefit from a glossary, perhaps with examples.

Insert the words “Add this method below the existing initWithName:quantity: method” before “implement it like this” in the instructions prior to adding the initWithCoder: method.

End of second paragraph:

…and call the new project “Shopping List.”

—this should probably be “Shopping List”. (with the period outside the quotes, as the period isn’t actually part of the new project’s name)

The applicationDidFinishLaunching: method should be application:didFinishLaunchingWithOptions: (this changed from iPhone/iOS SDK at time of original writing)

The fisrt code block under “Rewrinting the init Method” had the following line:

`NSLog(@“Object was initialized!”);`

But regarding what it was done before, it should be:

`NSLog(@“A WonderfulNumber object was initialized!”);`

In the code block under :
> “With this in mind, let’s change the displaySomeText: method in TextApp to the following:”

In the first block of the if statement,
there is a problem of typo at the blue line
> `stringToOutput = @“Access Granted!”;`

Regarding what it was done before, either `Access Granted!` should be in the same red who underline the modifications, either it should be replaced by `You clicked the button!`.

In the first code block of the page, the code to be changed is not in red. So, unlike the others code block of the book, the part to be changed is not obviously pointed out.

In the section on floating-point numbers, the exercise has us set the value of the variable to “3.14159265”, but when the program is run, the value is presented in the text box as “3.141593”, rounding off the last few digits, and there is no explanation in the text for why this happens. So I don’t know if I’ve done something wrong, or if the text has just omitted that detail.

after the code sample, the paragraph ends with “the value output to the text view is now the value returned by the generateValue method (5.0).”

the actual value output by my program is (5.000000). minor issue, but it would be nice if the text matched up with the actual output so i can be sure i’ve not done something wrong.

After adding the code for addNewItemToShoppingList it asks you to Build & Run the code and you will be able to add new items to the shopping list. However there was no instruction to “remind” you to link the Button to the addNewItemToShoppingList event using the HUD. Only held me up for a couple of minutes but worth mentioning.
Version 2010-2-16

“In modern mathematics, writ- ing “2 + 4 * 5” would be interpreted as “2 + 20” rather than “8 * 5” because multiplication should be carried out before addition."
It should be “6 * 5” instead of “8 * 5”.