CCPhysicsBody Collision not working in cocos2d-swift v3.4 - iphone

Question

Here is code:
#interface MainScene : CCNode<CCPhysicsCollisionDelegate>
//.m
-(void)onEnter
{
[super onEnter];
mPhysicsWorld = [CCPhysicsNode node];
mPhysicsWorld.gravity = ccp(0,0);
mPhysicsWorld.debugDraw = YES;
mPhysicsWorld.collisionDelegate = self;
[self addChild:mPhysicsWorld];
//Body_A
{
CCSprite *sprite = [CCSprite spriteWithImageNamed:#"sprite_1.png"];
sprite.position = ccp(280, 220);
sprite.rotation = 13;
sprite.name = #"Body_A";
sprite.physicsBody.collisionGroup=#"Group1";
sprite.physicsBody.collisionType=#"typeA";
CGRect rect = {CGPointZero, sprite.contentSize};
CCPhysicsBody *body = sprite.physicsBody = [CCPhysicsBody bodyWithRect:rect cornerRadius:0.0];
body.velocity = ccp(1000, 2000);
body.angularVelocity = 1.0;
body.type = CCPhysicsBodyTypeDynamic;
[mPhysicsWorld addChild:sprite];
}
//Body_B
{
CCSprite *sprite = [CCSprite spriteWithImageNamed:#"sprite_2.png"];
sprite.position = ccp(380, 220);
sprite.rotation = 13;
sprite.name = #"Body_B";
sprite.physicsBody.collisionGroup=#"Group2";
sprite.physicsBody.collisionType=#"typeB";
CGSize size = sprite.contentSize;
CGPoint points[] = {
ccp(0, 0),
ccp(size.width, 0),
ccp(size.width/2, size.height),
};
CCPhysicsBody *body = sprite.physicsBody = [CCPhysicsBody bodyWithPolygonFromPoints:points count:3 cornerRadius:0.0];
body.velocity = ccp(1000, -1000);
body.angularVelocity = -1.0;
body.type = CCPhysicsBodyTypeDynamic;
[mPhysicsWorld addChild:sprite];
}
//Delegate method
- (BOOL)ccPhysicsCollisionBegin:(CCPhysicsCollisionPair *)pair typeA:(CCNode *)nodeA typeB:(CCNode *)nodeB
{
printf("Function Called\n"); //control not coming here
if([nodeA.name isEqualToString:#"Body_A"] && [nodeB.name isEqualToString:#"Body_B"])
{
return YES;
}
return NO;
}
Similar Question: Already tried this similar post but didn't get solution.

Answer 1

you are probably going to 'palm-forehead' , took me a while too :(
For both body A and body B the two lines below
sprite.physicsBody.collisionGroup=#"Group1";
sprite.physicsBody.collisionType=#"typeA";
are executed while physicsBody is still nil. Move the lines under the line :
CCPhysicsBody *body = sprite.physicsBody = [CCPhysicsBody bodyWithRect:rect cornerRadius:0.0];
ob cit. tested and verified, works on sim and device. Good luck with your project.