Collision detection Objective-C (cocos2d) - objective-c

Question

I´m making an iphone app in objective-c with cocos2d, in the code below I try to detect a collision and then run an animation. (The box1 is moved by touch)
When the "[self getChildByTag:d]" and "box1" collide AND overlap I get the "JUMP NOW!" displayed but I don't get the jump itself, but when the box1 is moved away from the "[self getChildByTag:d]" the jump occurs.
I understand that this probably has to do with the fact that the action is called many times, but please explain to me exactly what happens and please help me with a solution!
- (void)update:(ccTime)dt {
for (int d = lowestAvailableTag; d <= highestAvailableTag; d++) {
if ([self getChildByTag:d].position.y < (box1.position.y+45)&&
[self getChildByTag:d].position.x > (box1.position.x-45) &&
[self getChildByTag:d].position.x < (box1.position.x+45) ) {
NSLog(#"JUMP NOW!");
if ([self getChildByTag:d].position.x < 150) {
[[self getChildByTag:d] runAction:
[CCJumpTo actionWithDuration:1.5
position:ccp(240, 140) height:110 jumps:1]];
}
}
}
}
//albar

Answer 1

You can add some BOOL flag to detect if your jump occured. Smth like:
- (void) update:(ccTime)dt
{
if( jumpOccured == false )
{
BOOL needToJump = // your jump condition
if( needToJump == true )
{
// your jump code
jumpOccured = true;
}
}
}
by the way, if you have many possible collisions, you can use box2d to detect them