The squad class that holds our units.

Squad.swift

import SpriteKit
import Foundation

class Squad : SKNode {
    
    // Handle on all units in the squad.
    var units : Array<CharacterNode> = []
    
    // Current formation technique
    var formation : Formation?
    
    required init(coder aDecoder: (NSCoder!)) {
        super.init(coder: aDecoder)
    }
    
    override init() {
        super.init()
        // Hard code a formation for this squad.
        self.formation = Formation()
    }
    
    func addUnit(unit:CharacterNode) {
        // Add unit to local array.
        self.units.append(unit)
        
        // Add unit to world as a child of this node.
        self.addChild(unit)
    }
    
}