Dynamic UIMenuItems with #selector and dynamic methods - iphone

Question

I am trying to use UIMenuController for a dynamical menu (titles and actions come from a server). The problem is that I have to use UIMenuItems initWithTitle:action: where action is a #selector.
I can use #selector(dispatch:) but then I am not able to distinguish which of the items the user pressed. - (void)dispatch:(id)sender { NSLog(#"%#", sender); } says it is a UIMenuController and It don't have a method which would tell which menu item was pressed.
I can't just write 100 methods to dispatch every possible selector, ok there will not be more then 10 but still, this seems not a good idea.
Do I have to create dynamic methods for each such selector? http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtDynamicResolution.html? This seems odd too.
Any better propositions then this two?
// This approach doesn't work.
- (void)showMenu {
[self becomeFirstResponder];
NSMutableArray *menuItems = [[NSMutableArray alloc] init];
UIMenuItem *item;
for (MLAction *action in self.dataSource.actions) {
item = [[UIMenuItem alloc] initWithTitle:action.title action:#selector(action:)];
[menuItems addObject:item];
[item release];
}
UIMenuController *menuController = [UIMenuController sharedMenuController];
menuController.menuItems = menuItems;
[menuItems release];
[menuController update];
[menuController setMenuVisible:YES animated:YES];
}
- (void)action:(id)sender {
NSLog(#"%#", sender); // gives UIMenuController instead of UIMenuItem
// I can not know which menu item was pressed
}
// This approach is really ugly.
- (void)showMenu {
[self becomeFirstResponder];
NSMutableArray *menuItems = [[NSMutableArray alloc] initWithCapacity:5];
UIMenuItem *item;
NSInteger i = 0;
for (MLAction *action in self.dataSource.actions) {
item = [[UIMenuItem alloc] initWithTitle:action.text
action:NSSelectorFromString([NSString stringWithFormat:#"action%i:", i++])];
[menuItems addObject:item];
[item release];
}
UIMenuController *menuController = [UIMenuController sharedMenuController];
menuController.menuItems = menuItems;
[menuItems release];
[menuController update];
[menuController setMenuVisible:YES animated:YES];
}
- (void)action:(NSInteger)number {
NSLog(#"%i", number); // gives the index of the action in the menu.
}
// This is a hack, I have to assume that there will never be more then 15 actions
- (void)action0:(id)sender { [self action:0]; }
- (void)action1:(id)sender { [self action:1]; }
- (void)action2:(id)sender { [self action:2]; }
- (void)action3:(id)sender { [self action:3]; }
- (void)action4:(id)sender { [self action:4]; }
- (void)action5:(id)sender { [self action:5]; }
- (void)action6:(id)sender { [self action:6]; }
- (void)action7:(id)sender { [self action:7]; }
- (void)action8:(id)sender { [self action:8]; }
- (void)action9:(id)sender { [self action:8]; }
- (void)action10:(id)sender { [self action:10]; }
- (void)action11:(id)sender { [self action:11]; }
- (void)action12:(id)sender { [self action:12]; }
- (void)action13:(id)sender { [self action:13]; }
- (void)action14:(id)sender { [self action:14]; }

Answer 1

That approach would work, although you need a unique selector-name for every button and a mapping from that name to whatever you want to target.
For the selector name a unique string has to be chosen (UUIDs or maybe a sanitized & prefixed version of the title would work). Then you need one method that resolves the call and "alias" it with the different selector names:
- (void)updateMenu:(NSArray *)menuEntries {
Class cls = [self class];
SEL fwd = #selector(forwarder:);
for (MenuEntry *entry in menuEntries) {
SEL sel = [self uniqueActionSelector];
// assuming keys not being retained, otherwise use NSValue:
[self.actionDict addObject:entry.url forKey:sel];
class_addMethod(cls, sel, [cls instanceMethodForSelector:fwd], "v#:#");
// now add menu item with sel as the action
}
}
Now the forwarder can look up what URL is associated with the menu item:
- (void)forwarder:(UIMenuController *)mc {
NSLog(#"URL for item is: %#", [actionDict objectForKey:_cmd]);
}
To generate the selectors you could use something like:
- (SEL)uniqueActionSelector {
NSString *unique = ...; // the unique part
NSString *selString = [NSString stringWithFormat:#"menu_%#:", unique];
SEL sel = sel_registerName([selString UTF8String]);
return sel;
}

Answer 2

Unless the menu items do the same thing, why should they share an action? I would go ahead and write actions that specify a behavior you want and link the menu items up to those.