phaser-group-signals: onChildAdded, onChildRemoved, onChildKilled, onChildRevived

[samme]

GitHub / NPM

group.onChildAdded.add(function (child, parent){
    /* `child` was added to `parent` */
});

group.onChildRemoved.add(function (child, prevParent){
    /* `child` was removed from `prevParent` */
});

group.onChildKilled.add(function (child, parent){
    /* `child` was killed */
});

group.onChildRevived.add(function (child, parent){
    /* `child` was revived */
});

 

[tips4design]

Cool. In which cases would you use those? Child-adding is a synchronous task and you are usually the one doing it in the code so you could just call a function after you add it.

[samme]

Hi tips, definitely, you could; I suppose it helps with separation of concerns and could simplify complex relationships. I wanted to find a way some interested entity could monitor a group without ever having to visit its children.

I think the biggest advantage is you can respond to changes in children created after you've attached to the signal, forever. It also reduces signal volume for very large groups.

Slightly interesting: `onChildAdded` is triggered by auto-expanding Bullet groups and createIfNull: true. And you can monitor every game object by binding just 4 signals on `game.world`.