Re: [Rubycocoa-talk] @selector thingamabob.

[Dave H. <gr...@gr...>]

On Jan 20, 2006, at 13:11, Jonathan Paisley wrote:

> On 20 Jan 2006, at 20:49, Dave Howell wrote:
>
>> 	def alertDidEnd_returnCode_contextInfo(theAlert)
>> 		return
>> 	end
>>
>> Unfortunately, I can't do anything but one-button messages, because I 
>> can't get the return code back from the NSAlert. The call to 
>> 'beginSheetModalForWindow...' looks like this in Objective-C:
>>
>> beginSheetModalForWindow:[someWindow window]
>> 	modalDelegate:self
>> 	didEndSelector:@selector(alertDidEnd:returnCode:contextInfo:)
>> 	contextInfo:nil
>>
>> How exactly can I get a parameterized selector into this thing? In 
>> other words,  how do I do
>> 	@selector(alertDidEnd:returnCode:contextInfo:)
>> in RubyCocoa?
>
> Is your callback method being called? Your ruby method:
>
>    def alertDidEnd_returnCode_contextInfo(theAlert)
>
> doesn't have the right signature, because it's supposed to take three 
> arguments:
>
>    def alertDidEnd_returnCode_contextInfo(theAlert,code,context)

Not according to RubyCocoa. Like I said, the code as listed works 
"correctly."

If I change my callback method to
	def alertDidEnd_returnCode_contextInfo(theAlert, returnCode, 
contextInfo)

then the entire app blows apart:
	rb_main.rb:22: [BUG] Bus Error

Any attempt to add a second parameter to the callback method causes 
that result.

> Does using the 'code' argument there work?
>
> I think you can also use symbols for selectors (instead of strings) 
> e.g.,  :alertDidEnd_returnCode_contextInfo. Don't think it makes any 
> difference, just a matter of choice.

Well, it's a string because I was trying to get the parameters to pass 
properly, like
	'alertDidEnd_returnCode_contextInfo:returnCode:contextInfo"
or
	"@selector(alertDidEnd:returnCode:contextInfo"

But all such guesses failed one way or the other.