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Synotic · May 29, 2002, 10:07 PM

OK, this is really what's been limiting me for a while. Does anyone know how to do a really simple table view? My objective: To have a global (I believe they're what they're called) which is an array filled with A, B, and C. Then I want to put that in a single-columned table view...

|�A�|
|�B�|
|�C�|

In case anyone needs a visual.. Then at any time I want to be able to pass it any array and have it be populated.. So if I just happen to have an array like X, Y, Z I want to pass it to it and have it update. again..

|�A�|
|�B�|
|�C�| ↓

|�X�|
|�Y�|
|�Z�|

No extra fluff, I won't be deleting items, doing whatever.. this is all I need to do. Keep in mind that I am a Cocoa newbie.

Vasudevelopa · May 29, 2002, 10:21 PM

see this article:
<a href="http://www.cocoadevcentral.com/tutorials/showpage.php?show=00000036.php" target="_blank">http://www.cocoadevcentral.com/tutorials/showpage.php?show=00000036.php</a>
You will need to implement these 2 functions
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">- (int)numberOfRowsInTableView

NSTableView *)aTableView;
- (id)tableView

NSTableView *)aTableView objectValueForTableColumn

NSTableColumn *)aTableColumn</pre><hr /></blockquote>The first one should return [myArray count], the second should return [myArray objectAtIndex:rowIndex].
When you update the table views data source call [myTableView reloadData].
Don't forget to set the table views delegate and data source to whatever class you implement it in(in IB).

Synotic · May 30, 2002, 12:46 AM

OK, thanks for the response.. lemme just try to get some things cleared up.. When I put myArray in objectForValue and numberOfRows.. does this basically make myArray the data source?..

I've made MyController the delegate and data source for my table view.. so the class is is the data source?

Here is my code.. prepare to cringe.. I've done very little Cocoa..

<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">/* MyController */

#import <Cocoa/Cocoa.h>

@interface MyController : NSObject {
NSArray *myArray;
IBOutlet id mytableview;
}
- (void)tableViewSelectionDidChange

NSNotification *)aNotification;
- (int)numberOfRowsInTableView

NSTableView *)aTableView;
- (id)tableView

NSTableView *)aTableView objectValueForTableColumn

NSTableColumn *)aTableColumn;
- (void)awakeFromNib;
@end</pre><hr /></blockquote>and then..

<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">#import "MyController.h"

@implementation MyController
- (void)tableViewSelectionDidChange

NSNotification *)aNotification {
NSLog(@"selection did change&quot

;
}

- (int)numberOfRowsInTableView

NSTableView *)aTableView {
return [myArray count];
}

- (id)tableView

NSTableView *)aTableView objectValueForTableColumn

NSTableColumn *)aTableColumn {
return [myArray objectAtIndex:[mytableview selectedRow]];
}

- (void)awakeFromNib {
myArray = [NSArray arrayWithObjects:@"A", @"B", @"C", nil];
}

@end</pre><hr /></blockquote>Also, I will look at the source for the the tutorial you posted above, I'm sure it'll answer all my questions.. but just wanted to show you my code just in case anything blatantly obvious stuck out

Thanks a lot!

Ibson · May 30, 2002, 01:38 AM

Code looks good, just remember to retain the array when you in the awakeFromNib method. It should look like:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">myArray = [[NSArray arrayWithObjects:@"A", @"B", @"C", nil] retain];</pre><hr /></blockquote>Also remember to release it in the dealloc method:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">- (void)dealloc
{
[myArray release];
[super dealloc];
}</pre><hr /></blockquote>BTY, you have made the MyController class your data source, but that's fine. If you want to, you could add a category to NSArray and then make any array your data source. You can do this:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">@implementation NSArray (ArrayDataSource)

- (int)numberOfRowsInTableView

NSTableView *)aTableView
{
return [self count];
}

- (id)tableView

NSTableView *)aTableView objectValueForTableColumn

NSTableColumn *)aTableColumn
{
return [self objectAtIndex:[aTableView selectedRow]];
}
@end</pre><hr /></blockquote>Then just import that file (let's call it ArrayDataSource.m) and then all you need to do is set myArray as your table's data source and then you can remove the data source methods from your controller. If you do this, any array can instantly become a table's data source--it's very convenient. Also, you don't need to define any of the methods you have in your header file--they're already defined elsewhere in the AppKit's headers.

[ 05-30-2002, 02:46 AM: Message edited by: Ibson ]

Vasudevelopa · May 30, 2002, 01:50 AM

Looks alright, I don't know about [myTableView selectedRow]. Play around with it and see. Also call [myTableView reloadData] after you add items to the array in awakeFromNib.

Synotic · May 30, 2002, 02:18 AM

<blockquote>quote:<hr />Originally posted by Ibson:
Code looks good, just remember to retain the array when you in the awakeFromNib method. It should look like:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">myArray = [[NSArray arrayWithObjects:@"A", @"B", @"C", nil] retain];</pre><hr /></blockquote>Also remember to release it in the dealloc method:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">- (void)dealloc
{
[myArray release];
[super dealloc];
}</pre><hr /></blockquote>BTY, you have made the MyController class your data source, but that's fine. If you want to, you could add a category to NSArray and then make any array your data source. You can do this:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">@implementation NSArray (ArrayDataSource)

- (int)numberOfRowsInTableView

NSTableView *)aTableView
{
return [self count];
}

- (id)tableView

NSTableView *)aTableView objectValueForTableColumn

NSTableColumn *)aTableColumn
{
return [self objectAtIndex:[aTableView selectedRow]];
}
@end</pre><hr /></blockquote>Then just import that file (let's call it ArrayDataSource.m) and then all you need to do is set myArray as your table's data source and then you can remove the data source methods from your controller. If you do this, any array can instantly become a table's data source--it's very convenient. Also, you don't need to define any of the methods you have in your header file--they're already defined elsewhere in the AppKit's headers.<hr /></blockquote>OK, so if I make that ArrayDataSource.m file, I no longer need to have MyController be the data source? Or should I keep it? I also found the init method, I should probably use this rather than awakeFromNib right? Since I am doing nothing with any interface items..

So in the init method I should be something like this..

[mytableview setDataSource:myArray];

Then the "objectForValue" "numberOfRows" etc.. can all be removed from MyController? Also, should I import it through MyController.m or .h?

So now my table view and and array will be in sync? I update my array, I tell the table view to update, it updates?

Does the basic format of arrays if they are multi-columned (doesn't really pertain to this but just for future reference) the array looks like this right?

{{1, 2, 3, 4}, {5, 6, 7, 8}}

becomes..

|�1�|�2�|�3�|�4�|
|�5�|�6�|�7�|�8�|

right? is there any way to make it so that.. {{1, 2, 3, 4}, {5, 6, 7, 8}} turns into..

|�1�|�5�|
|�2�|�6�|
|�3�|�7�|
|�4�|�8�|

? This second question isn't really imperative.. just if any of you have time.

again.. thanks a lot this is a big help.

Ibson · May 30, 2002, 02:50 AM

If you implement the ArrayDataSource category, you can remove all data source methods from MyController. Import ArrayDataSource.m through MyController.m. You still need an awakeFromNib method, as you can't change properties of objects (your table view) that haven't been unarchived yet. So awakeFromNib should look like:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">- (void)awakeFromNib
{
myArray = [[NSArray arrayWithObjects:@"A", @"B", @"C", nil] retain];
[mytableview setDataSource:myArray];
}</pre><hr /></blockquote>If you update your array (in which case, myArray should be an NSMutableArray), and call [mytableview reloadData], everything will be in sync. As to your second question, multi-columned table views are generally managed using NSArrays of NSDictionaries (or other custom objects). So, in IB, give your two table columns an identifier (eg if 1 column is a name of something, and the second is its description, the first column should have the identifier "Name", the second, "Description"). Then, create an array of NSDictionaries, with each dictionary having the keys "Name" and "Description" and their associated values. Eg:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">myArray = [[NSArray arrayWithObjects:
[NSDictionary dictionaryWithObjectsAndKeys:
@"Cat", @"Name", @"Funky, and furry.", @"Description", nil],
[NSDictionary dictionaryWithObjectsAndKeys:
@"Dog", @"Name", @"Barks a lot.", @"Description", nil],
nil] retain];</pre><hr /></blockquote>Then, in ArrayDataSource.m, do this:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">- (id)tableView

NSTableView *)aTableView objectValueForTableColumn

NSTableColumn *)aTableColumn
{
return [[self objectAtIndex:[aTableView selectedRow]] objectForKey:[aTableColumn identifier]];
}</pre><hr /></blockquote>(If you wanted to, you could see whether the array's object is a string or a dictionary--ask how if you need to know).
If you implement this, the table columns will then be automatically filled with their respective values.
Hope this makes sense!
(BTY, see the excellent <a href="http://www.cocoadev.com/index.pl?SortingTableViewByColumn" target="_blank">tutorial</a> at CocoaDev for more info)

[ 05-30-2002, 04:04 AM: Message edited by: Ibson ]

Synotic · May 31, 2002, 09:27 PM

OK, I really appreciate it but I can't get it to work!?!? Frustrating to say in the least..

MyController.h:

<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">#import <Cocoa/Cocoa.h>

@interface MyController : NSObject
{
IBOutlet id tableview;
NSArray *myArray;
}
- (void)awakeFromNib;
- (void)dealloc;
@end</pre><hr /></blockquote>MyController.m:

<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">#import "MyController.h"
#import "ArrayDataSource.m"

@implementation MyController

- (void)awakeFromNib
{
myArray = [[NSArray arrayWithObjects:@"A", @"B", @"C", nil] retain];
[tableview setDataSource:myArray];
}

- (void)dealloc {
[myArray release];
[super dealloc];
}
@end</pre><hr /></blockquote>Note that it's imported..

ArrayDataSource.m:

<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">#import "MyController.h"

@implementation NSArray (ArrayDataSource)

- (int)numberOfRowsInTableView

NSTableView *)aTableView
{
return [self count];
}

- (id)tableView

NSTableView *)aTableView objectValueForTableColumn

NSTableColumn *)aTableColumn
{
return [self objectAtIndex:[aTableView selectedRow]];
}
@end</pre><hr /></blockquote>I don't have an ArrayDataSource.h.. still no luck.. although I put virtually nothing in there.

BTW, I stuck in an "import "MyController.h"" at the top because it wasn't recognizing all the table views. After all the errors are gone I get one error:

"Build failed (see build log for details)"

and the build log..

<blockquote>quote:<hr />/usr/bin/jam -d1 JAMBASE=/Developer/Makefiles/pbx_jamfiles/ProjectBuilderJambase JAMFILE=- build ACTION=build _DEFAULT_GCC_VERSION=2.95.2 _GCC3_IS_IN_OFFICIAL_LOCATION=YES BUILD_STYLE=Development "CPP_HEADERMAP_FILE=/Users/synotic/Cocoa Table/build/Cocoa Table.build/Cocoa Table.build/Cocoa Table.hmap" "SRCROOT=/Users/synotic/Cocoa Table" "OBJROOT=/Users/synotic/Cocoa Table/build" "SYMROOT=/Users/synotic/Cocoa Table/build" "DSTROOT=/tmp/Cocoa Table.dst"
...updating 13 target(s)...
Cp /Users/synotic/Cocoa Table/build/Cocoa Table.app/Contents/PkgInfo
BuildPhase <CopyResources>Cocoa Table.app
Completed phase <CopyResources> for <CopyResources>Cocoa Table.app
CompileC /Users/synotic/Cocoa Table/build/Cocoa Table.build/Cocoa Table.build/Objects-normal/ppc/MyController.o
CompileC /Users/synotic/Cocoa Table/build/Cocoa Table.build/Cocoa Table.build/Objects-normal/ppc/ArrayDataSource.o
BuildPhase <DeriveAndCompileSources>Cocoa Table.app
Completed phase <DeriveAndCompileSources> for <DeriveAndCompileSources>Cocoa Table.app
MasterObjectFile.Combine /Users/synotic/Cocoa Table/build/Cocoa Table.build/Cocoa Table.build/Objects-normal/ProjectBuilderMasterObjectFile.o
/usr/bin/ld: multiple definitions of symbol .objc_category_name_NSArray_ArrayDataSource
/Users/synotic/Cocoa Table/build/Cocoa Table.build/Cocoa Table.build/Objects-normal/ppc/MyController.o definition of absolute .objc_category_name_NSArray_ArrayDataSource (value 0x0)
/Users/synotic/Cocoa Table/build/Cocoa Table.build/Cocoa Table.build/Objects-normal/ppc/ArrayDataSource.o definition of absolute .objc_category_name_NSArray_ArrayDataSource (value 0x0)

/usr/bin/c++ -arch ppc -keep_private_externs -nostdlib -filelist "/Users/synotic/Cocoa Table/build/Cocoa Table.build/Cocoa Table.build/Objects-normal/LinkFileListPrelink" -r -o "/Users/synotic/Cocoa Table/build/Cocoa Table.build/Cocoa Table.build/Objects-normal/ProjectBuilderMasterObjectFile.o"

...failed MasterObjectFile.Combine /Users/synotic/Cocoa Table/build/Cocoa Table.build/Cocoa Table.build/Objects-normal/ProjectBuilderMasterObjectFile.o ...<hr /></blockquote>Any ideas?

Ibson · Jun 1, 2002, 02:53 AM

OK, this should be the contents of each file:

a) MyController.h:

<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">#import <Cocoa/Cocoa.h>

@interface MyController : NSObject
{
IBOutlet NSTableView *tableview;
NSArray *myArray;
}
@end</pre><hr /></blockquote>A hint: in IB, you should define what class each outlet is. That is, when you created the tableview outlet, define it as an NSTableView. Then change your header to like it is above. It just makes everything a little nicer and lets the compiler do better checking. You don't need to define awakeFromNib and dealloc, as they're already defined in the Cocoa headers.
b) MyController.m:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">#import "MyController.h"
#import "ArrayDataSource.h"

@implementation MyController

- (void)awakeFromNib
{
myArray = [[NSArray arrayWithObjects:@"A", @"B", @"C", nil] retain];
[tableview setDataSource:myArray];
}

- (void)dealloc
{
[myArray release];
[super dealloc];
}

@end</pre><hr /></blockquote>c) ArrayDataSource.h:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">#import <AppKit/AppKit.h>

@interface NSArray (ArrayDataSource)
- (int)numberOfRowsInTableView

NSTableView *)aTableView;
- (id)tableView

NSTableView *)aTableView objectValueForTableColumn

NSTableColumn *)aTableColumn row

int)rowIndex;
@end</pre><hr /></blockquote>d) ArrayDataSource.m:
<blockquote>code:<hr /><pre style="font-size:x-small; font-family: monospace;">#import "ArrayDataSource.h"

@implementation NSArray (ArrayDataSource)

- (int)numberOfRowsInTableView

NSTableView *)aTableView
{
return [self count];
}

- (id)tableView

NSTableView *)aTableView objectValueForTableColumn

NSTableColumn *)aTableColumn row

int)rowIndex
{
return [self objectAtIndex:rowIndex];
}
@end</pre><hr /></blockquote>I guarantee that will compile properly

--last night I had just copy-and-pasted your and changed it a bit--I don't know how objectAtIndex:[aTableView selectedRow] snuck in (it was late).

[ 06-01-2002, 03:56 AM: Message edited by: Ibson ]

Synotic · Jun 1, 2002, 04:11 PM

OK, now everything works perfectly, even updating, thanks a lot

I wish this was hte only problem I was facing though.. more will be in a different topic.