IHMenuItemValidator

IHMenuItemValidator.m

//
//  IHMenuItemValidator.m
//  GarageSale
//
//  Created by ilja iwas on 12.12.14.
//
//

#import "IHMenuItemValidator.h"

@implementation IHMenuItemValidator

/** If you have Cocoa controller or delegate classes that are so big (yes, I know, bad practice), 
that your validateMenuItem: method spans several screen pages, this method helps you to:
 
 a) break validateMenuItem: into several smaller pieces of code
 b) but your validation code right next to action method
 
 To use it, change your validateMenuItem: method to look like this:
 
 - (BOOL)validateMenuItem:(NSMenuItem *)item
 {
	return [IHMenuItemValidator validateMenuItem:item withTarget:self];
 }
 
 In case, e.g. validateMenuItem is called for the action 'delete:' , the code looks for a method called validateDelete:(NSMenuItem*) menuItem. Implement your validation code in that method and say goodbye to gigantic if/else if/ constructs.
 */

+ (BOOL) validateMenuItem:(NSMenuItem *)inMenuItem withTarget:(id) inTarget
{
	NSString	*selectorName = NSStringFromSelector(inMenuItem.action);
	NSString	*firstLetter = [selectorName substringToIndex:1];
	
	firstLetter = firstLetter.uppercaseString;
	selectorName = [firstLetter stringByAppendingString:[selectorName substringFromIndex:1]];
	
	NSString	*validateSelectorName = [@"validate" stringByAppendingFormat:@"%@",selectorName];
	SEL			validationSelector = NSSelectorFromString(validateSelectorName);
	
	if ([inTarget respondsToSelector:validationSelector])
	{
		NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[[inTarget class] instanceMethodSignatureForSelector:validationSelector]];
		
		invocation.target = inTarget;
		invocation.selector = validationSelector;
		[invocation setArgument:&inMenuItem atIndex:2];
		
		[invocation invoke];
		
		BOOL result;
		
		[invocation getReturnValue:&result];
		return result;
	}
	return YES;
}

@end