ccTouchesBegan vs ccTouchBegan - Touch Detection & SIGABRT crash - objective-c

Question

I'm currently doing an application where I'm trying to detect touch-positions of the user.
I changed from ccTouchBegan to ccTouchesBegan in the process of implementing the "detect touch-position" function.
But I can't get it to work. I changed from ccTouchBegan to ccTouchesBegan:
-(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
instead of using:
-(BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event{
When i did this the whole thing crashes when I click the screen. Generating a SIGABRT error higlighting:
#ifdef __IPHONE_OS_VERSION_MAX_ALLOWED
-(BOOL) ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
NSAssert(NO, #"Layer#ccTouchBegan override me");
return YES;
}
#endif
#end
So my questions are:
Why do you think it crashes?
What's the difference between ccTouchBegan & ccTouchesBegan? Multi touch abilities?
For further help, this is my code:
-(id) init
{
if( (self=[super init])) {
[CCTexture2D setDefaultAlphaPixelFormat:kCCTexture2DPixelFormat_RGBA8888];
self.isTouchEnabled = YES;
// Set up background
background = [CCSprite spriteWithFile:#"Image.png"];
background.scaleX = 1;
background.scaleY = 1;
background.position = ccp(0,0);
[self addChild:background];
[[CCTouchDispatcher sharedDispatcher]addTargetedDelegate:self
priority:0
swallowsTouches:YES];
// Preload sound effect
soundFile = [SimpleAudioEngine sharedEngine];
if (soundFile != nil) {
[soundFile preloadBackgroundMusic:#"sound.wav"];
}
}
return self;
}
-(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
NSLog(#"ccTouchesBegan");
// Sets the sound variable to YES
ifOne = YES;
prevPos = [touch locationInView:[touch self]];
prevPos = [[CCDirector sharedDirector] convertToGL:[touch locationInView:touch.self]];
[self schedule:#selector(timerUpdate:) interval:0.1];
//return YES;
}

Answer 1

It's a nice feature in cocos2d which lets you swallow touches in cases that you want to handle only a single touch event.
Try adding this function to your class:
- (void) registerWithTouchDispatcher {
[[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:INT_MIN+1 swallowsTouches:YES];
}

Answer 2

ccTouchesBegan happens the second you tap the screen
ccTouchesEnded happens the second you let go after tapping on the screen
and instead of
-(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
instead of using:
-(BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event{
try using
-(void)ccTouchesBegan:(UITouch *)...
or
-(void)ccTouchesBegan:(NSSet *)...
or
-(BOOL)ccTouchesBegan:(NSSet *)...
your problem may just be invalid data types or some crap like that, my advice is just try switching the types of touches around.
I would give more info but you didn't provide alot of information to work with, so this is the best I can do.