passing blocks as parameters and calling them

Now, it's possible that you know something that I don't, but I wasn't aware of any feature allowing one to store blocks in variables that could then be used later...

alright, I just read something here that tells me that I'm wrong and you're right:
http://pragmaticstudio.com/blog/2010/7/28/ios4-blocks-1

I don't have any experience with this, but based on skimming through that article, I think the proper way of declaring a block variable with the name block would be like this:

Code:

void (^[b]block[/b])(BOOL) = ^ (BOOL noshow) {
    if(noshow){
        AutoTracView.hidden = YES;
        MarineTracView.hidden = YES;        
    }
};

I've bolded block to clarify that I'm using that to say what the name of the block is, not that it is a block (the ^ symbol already conveys the fact that it's a block.)

I hope I've helped! (And if I haven't... I am curious... I've never tried storing a block as a variable before, and I'd like to see how it's done.)

 

This blog shows how to save and later use a block

http://pragmaticstudio.com/blog/2010/9/15/ios4-blocks-2

The block property should be declared as copy and should be referenced with self.block.

 

This is possible but, one thing to remember is that the block lives on the stack. What this means is that the moment this method returns, your block is invalid and should not be called. What you'll need to to do is either:

• Assign the block to a property with the 'copy' attribute
• Copy the block manually using the -copy method
  
  Code:

  block = [^(BOOL noshow)
          {
              if(noshow){
                  AutoTracView.hidden = YES;
                  MarineTracView.hidden = YES;
                  
              }
          } copy];

If you are using the first method with ARC, your memory management should be handled by the compiler (if ARC is not enabled, be sure to free the block in your -dealloc method/when you are done with it). If you are manually copying it, make sure you call -release on the block (and nil out the variable) once you are done with it!

Edit: One more thing, don't do direct variable accesses inside the block! It looks like the two views you are accessing will most likely not be initialized at that point and will become static values inside the block. In this case, you'll be effectively calling nil. I would suggest moving those values over to either public properties or private properties in a class extension and the use something like 'self.autoTracView.hidden' instead of 'AutoTracView.hidden' (same with MarineTracView).

 

I typed this a while ago while the question was different I think it will give you a ok overview.
http://forums.macrumors.com/showthread.php?t=1225712