Get the oldest element spawned in group?

[AGoodUsername]

Say I had a group:

this.group = game.add.group();

and I spawned sixteen elements, one after another. How would I get the first one spawned?

this.group.getAt(0);

only works half of the time.

[AGoodUsername]

Something like this.lines.getFirstAlive();??

[nkholski]

I'd guess that this.group.children is in the order the children was added (firstElement = this.group.children[0]) but I haven't tried.

Otherwise, or if I use the group as a pool which would mess up the order anyway, I would add a custom property to the group.

If I really only needed the last:

this.group.add(element);
this.group.firstElement = this.group.firstElement ? this.group.firstElement : element;

If I wanted to keep track of all:

this.group.add(element);
this.group.elementOrder.push(element); // this.group.elementOrder is an array.

// Get the first one:
firstElement = this.group.elementOrder[0];

// Get the first one out of cue and put the second one as first:
firstElement = this.group.elementOrder.pop(0);

 

[AGoodUsername]

11 hours ago, nkholski said:

I'd guess that this.group.children is in the order the children was added (firstElement = this.group.children[0]) but I haven't tried.

Otherwise, or if I use the group as a pool which would mess up the order anyway, I would add a custom property to the group.

If I really only needed the last:

this.group.add(element);
this.group.firstElement = this.group.firstElement ? this.group.firstElement : element;

If I wanted to keep track of all:

this.group.add(element);
this.group.elementOrder.push(element); // this.group.elementOrder is an array.

// Get the first one:
firstElement = this.group.elementOrder[0];

// Get the first one out of cue and put the second one as first:
firstElement = this.group.elementOrder.pop(0);

 

Sorry if I'm doing something wrong, but it says this.group.elementOrder and firstElement are undefined. I tried this.lines.children[0].kill();, but it still has a problem; sometimes it kills, the first, sometimes the second. Now, my guess to fix this would be to use .pop()?

[nkholski]

Yes. It would be custom properties. You need to add them, like this "mygroup.firstElement = null;" or "mygroup.elementOrder = []". If you use the latter your would pop it to "firstElement" as in my example then kill it with "firstElement.kill();".

[AGoodUsername]

25 minutes ago, nkholski said:

Yes. It would be custom properties. You need to add them, like this "mygroup.firstElement = null;" or "mygroup.elementOrder = []". If you use the latter your would pop it to "firstElement" as in my example then kill it with "firstElement.kill();".

		this.lines.firstElement = [];
		this.lines.elementOrder = [];

and

			this.lines.elementOrder.push(this.lines);
			this.lines.firstElement = this.lines.elementOrder[0];
			this.lines.firstElement = this.lines.elementOrder.pop(0);
			this.lines.firstElement.kill();
			

are the new lines I added. However, it gives me the error this.lines.firstElement.kill is not defined.

[nkholski]

First, I had two suggestions, just a single reference or an array to keep track of the order of all children. I think you can skip the "firstElement" property and go for the array with "elementOrder". I guess that "this.lines" is a group? What you do is pushing a refrence to the group itself. 

 

// 1. Make a group and add custom property "elementOrder":
this.lines = this.game.add.group();
this.lines.elementOrder = [];

// 2. Make a new line (a sprite in this example):
var line = this.game.add.sprite(x, y, 'spritesheet');

// 3. Add it to the group
this.lines.add(line);

// 4. Push it to elementOrder:
this.lines.elementOrder.push(elementOrder);

// 5. Get first element and kill it: (in my previous example I showed both how to keep the element, and to pop it. But you probably want to pop it)
var firstElement = this.lines.elementOrder.pop(0);
firstElement.kill();

 

2-4 could be repeated anytime in your code, adding unlimited number of lines and still keep track of the order. (With modification you could use a pool, reusing lines and just push the references)

[AGoodUsername]

3 hours ago, nkholski said:

First, I had two suggestions, just a single reference or an array to keep track of the order of all children. I think you can skip the "firstElement" property and go for the array with "elementOrder". I guess that "this.lines" is a group? What you do is pushing a refrence to the group itself. 

 

// 1. Make a group and add custom property "elementOrder":
this.lines = this.game.add.group();
this.lines.elementOrder = [];

// 2. Make a new line (a sprite in this example):
var line = this.game.add.sprite(x, y, 'spritesheet');

// 3. Add it to the group
this.lines.add(line);

// 4. Push it to elementOrder:
this.lines.elementOrder.push(elementOrder);

// 5. Get first element and kill it: (in my previous example I showed both how to keep the element, and to pop it. But you probably want to pop it)
var firstElement = this.lines.elementOrder.pop(0);
firstElement.kill();

 

2-4 could be repeated anytime in your code, adding unlimited number of lines and still keep track of the order. (With modification you could use a pool, reusing lines and just push the references)

I'm spawning the lines with

			this.ray = this.lines.getFirstDead();
			this.ray.scale.setTo(2, 1);
			this.ray.tint = 16777215;
			this.ray.reset(101, 20);
			this.ray.angle = -90;
			this.ray.body.angularVelocity = 100;

because I want to clone them, so is this

			//kill function
			this.lines.elementOrder = [];
			this.lines.elementOrder.push(this.ray);
			var firstElement = this.lines.elementOrder.pop(0);
			firstElement.kill();
			

 

all right?

[nkholski]

The first two lines in the kull function don't belong there.

Add this just once when creating the group:
this.lines.elementOrder = []; 

Put this in your spawn function:
this.lines.elementOrder.push(this.ray);

[AGoodUsername]

18 minutes ago, nkholski said:

The first two lines in the kull function don't belong there.

Add this just once when creating the group:
this.lines.elementOrder = []; 

Put this in your spawn function:
this.lines.elementOrder.push(this.ray);

lines group:

		this.lines = game.add.group();
		this.lines.enableBody = true;
		this.lines.physicsBodyType = Phaser.Physics.ARCADE;
		this.lines.createMultiple(50, 'line');
		this.lines.elementOrder = []; 

spawning lines:

                r = Math.random();	
		if(r < 0.51){
			this.ray = this.lines.getFirstDead();
			this.lines.elementOrder.push(this.ray); 
			this.ray.scale.setTo(2, 1);
			this.ray.tint = 16777215;
			this.ray.reset(101, 20);
			this.ray.angle = -90;
			this.ray.body.angularVelocity = game.rnd.integerInRange(100, 125);
		}

kill function:

			var firstElement = this.lines.elementOrder.pop(0);
			firstElement.kill();
			

 

It kills the second one spawned if there are two.

Thanks for your time, I know how frustrating it must be

[nkholski]

Sorry, my bad. Use shift() instead of pop() and it should work.

[AGoodUsername]

14 hours ago, nkholski said:

Sorry, my bad. Use shift() instead of pop() and it should work.

THANK YOU SO MUCH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! (digital hug)(spam emote)