Accessing a variable from an other class without the use of static or global - actionscript-3

Question

i am trying to get an Array from a class to an other class but i can't use static or global variable for it.
in my class Jeu.as, i have 3 arrays (t_map1, t_map2 and t_map3) that represents my game map. t_map is an array that can content one of those map and a place where i can change it. I want to take the map use (form t_map) to my character (Perso.as) so it can know where it can walk or not.
The problem is that i don't know how to bring t_map from Jeu.as to Perso.as... I have tried to use a static variable (as seen in other answer) but it don't work because the map have to change...
How can i create a variable that can contain my array in my perso.as class?
in short, i want to bring t_map values form my jeu.as to an other variable in perso.as

Answer 1

All you really need to do is give both instances a reference to the same arrays, or give Perso a reference to Jeau. Static variables are a really bad idea, even if there's nothing inherent to this situation that would keep them from working for you.
Here's what a solution that uses Dependency Injection would look like:
package model {
public class Jeau extends EventDispatcher {
protected var _tMap1:Array = new Array();
protected var _tMap2:Array = new Array();
protected var _tMap3:Array = new Array();
//consider using more descriptive variable names
//or an array of arrays (one map in each index)
public function get tMap1():Array {
return _tMap1;
}
public function set tMap1(value:Array):void {
if (value != _tMap1) {
_tMap1 = value;
dispatchEvent(new Event('tMap1Changed'));
}
}
public function get tMap2():Array {
return _tMap2;
}
public function set tMap2(value:Array):void {
if (value != _tMap2) {
_tMap2 = value;
dispatchEvent(new Event('tMap2Changed'));
}
}
public function get tMap3():Array {
return _tMap3;
}
public function set tMap3(value:Array):void {
if (value != _tMap3) {
_tMap3 = value;
dispatchEvent(new Event('tMap3Changed'));
}
}
protected function somethingThatChangesMap1(index:int, value:String):void {
_tMap1[index] = value;
dispatchEvent(new Event('tMap1Changed'));
}
}
}
I've assumed this is a View class--you haven't given many details. You listen for events coming out of the model Class and then update the View based on whatever is in those arrays. By getting the whole instance, you have the ability to listen for these events. Otherwise, you'd have to use some other mechanism to communicate the change (such as the event bus used in Roenter link description herebotLegs).
package view {
class Perso extends MovieClip {
protected var jeau:Jeau;
public function get jeau():Jeau {
return _jeau;
}
public function set jeau(value:Jeau):void {
if (value != _jeau) {
_jeau = value;
_jeau.addEventListener('map1Changed', doMap1Stuff);
_jeau.addEventListener('map2Changed', doMap2Stuff);
_jeau.addEventListener('map3Changed', doMap3Stuff);
doMap1Stuff();
doMap2Stuff();
doMap3Stuff();
}
}
protected function doMap1Stuff(e:Event=null) {
//do actions depending on the state of map1 here
}
protected function doMap2Stuff(e:Event=null) {
//do actions depending on the state of map2 here
}
protected function doMap3Stuff(e:Event=null) {
//do actions depending on the state of map3 here
}
}
}
This is just an example of how you'd use a third Class to combine the first two. I wouldn't necessarily do it exactly like this:
package control {
public class MainGame {
protected var jeau:Jeau;
protected function perso:Perso;
public function MainGame() {
jeau = new Jeau();
//jeau setup
perso = new Perso();
perso.jeau = jeau;
}
}
}

Answer 2

Sounds like you need some simple accessors.
In Jeu, you'll want something to retrieve the maps like this:
function getMap(mapNumber:int):Array
{
switch(mapNumber)
{
case 1:
return t_map1;
case 2:
return t_map2;
case 3:
return t_map3;
default:
trace("Error: that's not a valid map number!")
}
}
If you saved your maps in another encompassing Array (lets call it allTheMaps), the function would look much nicer:
function getMap(mapNumber:int):Array
{
allTheMaps[mapNumber];
}
Then in Perso, you need to store a reference (or several if it needs to know about multiple maps at the same time) of an array to store the map in. You'll also need a function to set the data:
var theMap:Array;
function setMap(theMap:Array):void
{
myMap = theMap;
}
Now you can pass a map from an instance of Jeu to an instance of Perso:
var Jeu = new Jeu();
var Perso = new Perso();
...
Perso.setMap(Jeu.getMap(1));