Re: ArrayController vs Pop-up button vs Transformer -- three way tag team death match!
Re: ArrayController vs Pop-up button vs Transformer -- three way tag team death match!
- Subject: Re: ArrayController vs Pop-up button vs Transformer -- three way tag team death match!
- From: Ben Golding <email@hidden>
- Date: Tue, 19 Apr 2011 23:20:01 +1000
On 19/04/2011, at 18:19, Quincey Morris wrote:
> On Apr 19, 2011, at 00:41, Ben Golding wrote:
>
>> I am a bit stumped. I have an array controller which I have hooked up to a pop-up button and that works quite well. The members of the array are NSStrings but I would like to reformat them when they're displayed by the pop-up button. Seems fairly straightforward, I thought I'd just write a little transformer to do that.
>>
>> I plugged everything together and was surprised that that the transformer was raising an exception because it was being passed an NSObjectControllerProxy as its argument, not an NSString as I'd been expecting.
>
> Can you list explicitly all the NSPopUpButton bindings you're using?
Sure, I'm using content to bind to an array controller bound to an array of pop-up button titles and selected index (though I'm picking up the selected object using [[arrayControlled selectedObjects] objectAtIndex:0]).
I've also tried binding to contentValues which was unsuccessful too.
> The bindings for popup buttons are very nasty. You have to figure out what/whether to bind 'content', 'contentObjects' and 'contentValues'. Only after you've got that right can you decide which of the 'selected...' bindings you want to use.
>
> 'content', 'contentObjects' and 'contentValues' correspond to controller proxies, strings and represented objects, but I couldn't tell you off-hand which corresponds to what. It's anybody's guess whether the documentation (http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/CocoaBindingsRef/BindingsText/NSPopUpButton.html) is actually correct -- several of the pages in that document are wrong and/or incomplete -- and it's a puzzle sometimes to understand what the documentation even means.
What I'd found was that the documentation doesn't indicate what the ValueTransformer indicated is passed. It seems to be a controller object, not the pop-up button item's title which is the only thing that seems to make sense in the context.
> TBH, I've generally found it easier *not* to use bindings for NSPopUpButton content, but provide it the traditional way ('-[NSPopUpButton insertItem...]'), and just use a binding for 'selectedIndex'. But maybe I'm just a coward.
I share your fear but the win with bindings is too good to avoid. I try to think of these sort of frustrations as part of the learning process. I can really sympathise with wanting to fall back to the "old way".
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