Make a sprite only jump once - ios

Question

Working with Xcode, Spritebuilder and Cocos2d, I am trying to let the players sprite only jump 1 single time. So when the player taps the screen, the sprite jumps, and only when it has landed, the player should again be able to jump again. I haven't found any clear explanations so far, so hence my question.
Here's my code
Edit so that the code only lets the sprite jump once:
static const CGFloat scrollSpeed = 0.4;
BOOL isInAir;
#implementation GameScene
{
CCSprite *player1;
CCPhysicsNode *physicsNode1;
CCNode *ground1;
CCNode *ground2;
}
- (void)didLoadFromCCB
{
self.userInteractionEnabled = TRUE;
grounds = #[ground1, ground2]
}
- (void)update:(CCTime)delta
{
// moves the player to the right
player1.position = ccp(player1.position.x + delta * scrollSpeed, player1.position.y);
// move the camera with the player
physicsNode1.position = ccp(physicsNode1.position.x - (scrollSpeed *delta), physicsNode1.position.y);
// loop the ground
for (CCNode *ground in grounds)
{
// get the world position of the ground
CGPoint groundWorldPosition = [physicsNode1 convertToWorldSpace:ground.position];
// get the screen position of the ground
CGPoint groundScreenPosition = [self convertToNodeSpace:groundWorldPosition];
// if the left corner is one complete width off the screen, move it to the right
if (groundScreenPosition.x <= (-1 * ground.contentSize.width))
{
// puts the ground piece that is about to leave the screen behind the last one
ground.position = ccp(ground.position.x + 600, ground.position.y);
//NSLog(#"player1 pos: %#", NSStringFromCGPoint(ground.position));
}
}
// clamp velocity
float yVelocity = clampf(player1.physicsBody.velocity.y, -1 * MAXFLOAT, 200.f);
player1.physicsBody.velocity = ccp(0, yVelocity);
}
- (void)touchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
if (isInAir == NO)
{
[player1.physicsBody applyImpulse:ccp(0, 150)];
isInAir = YES;
}
}
- (BOOL) ccPhysicsCollisionBegin:(CCPhysicsCollisionPair *)pair player1:(CCNode *)player1 ground: (CCNode *)ground
{
NSLog(#"player is touching the ground");
isInAir = NO;
return YES;
}
#end

Answer 1

You can use a BOOL. Here is my code for a jump on touch:
BOOL isInAir;//Make this global.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
/* Called when a touch begins */
UITouch *touch = [touches anyObject];
SKSpriteNode *node = [self nodesAtPoint:[touch locationInNode:self]];
if (isInAir == NO)
{
CGFloat impulseX = 0.0f;
CGFloat impulseY = 600.0f;
[node.physicsBody applyImpulse:CGVectorMake(impulseX, impulseY) atPoint:node.position];
isInAir = YES;
//other stuff
}
}
Then when you contact ground, set isInAir to NO.