Hallo Henri Your assumption about how formatters should work are correct. To provide a useful answer I have setup a mini project here, because I have stumbled over a detail I did not now:
http://public.me.com/pmau I took your approach and implemted a minimal datasource and a "Foo" object. This is not a great example, but here's what II did not know: When you wire up the formatter to the text field cell in IB, "setFormatter" is called on the TextFieldCell, which in turn will call your formatting code withe the cell's title: run [Switching to process 7123] Running… 2010-01-03 12:39:47.790 Formatter[7123:a0f] NSCFString Cell Title 2010-01-03 12:39:47.810 Formatter[7123:a0f] Foo <Foo: 0x1139291d0> 2010-01-03 12:39:47.811 Formatter[7123:a0f] Foo <Foo: 0x1151000a0> 2010-01-03 12:39:47.811 Formatter[7123:a0f] Foo <Foo: 0x1151000b0> Therefore you have too prepare to receive at least one object, which is not "Foo". Interestingly, I could not find that little detail in the documentation. If you want to return an instance Foo from your datasource, it is much more convenient to write your own NSCell subclass, because you can control editing and formatting much easier. You can even use an attached formatter that you setup in IB, passing it a property of Foo. All the best, Patrick On Jan 3, 2010, at 1:47 , Henri Häkkinen wrote: > Hello. > > I have an array of custom Foo objects which I would need to display in an > NSTableView object. I implement the data source delegate like this: > > - (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView { > return [arrayOfFoos count]; > } > > - (id)tableView:(NSTableView *)tableView > objectValueForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger) row { > return [arrayOfFoos objectAtIndex:row]; > } > > Then I have NSFormatter subclass FooFormatter which takes in a Foo object and > converts it to a string. This formatter object is attached to the formatter > property of the TextFieldCell class in the NSTableView's table column. The > FooFormatter is like this: > > @implementation FooFormatter > > - (NSString *)stringForObjectValue:(id)anObject { > if ([anObject isKindOfClass:[Foo class]] == NO) { > [NSException raise:NSInvalidArgumentException format:@"Wrong > object"]; > } > Foo *foo = (Foo *)anObject; > NSString *string; > // ... convert foo into string ... > return string; > } > > @end > > I am assuming here that the object returned by the data source > objectValueForTableColumn: is passed to the formatter's stringForObjectValue: > before it is displayed in the text field cell -- this seems not to be the > case. I would like to keep formatting of Foo objects separate from the data > source (if possible) since I intend to implement multiple different > FooFormatter derived classes suited for different situations. > > The Cocoa docs seem to be a little low on details on how these NSFormatter > objects are supposed to work. Can anybody give me any insight? Would be > appreciated. Thanks. > > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/cocoa-dev/pmau%40me.com > > This email sent to p...@me.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
