How to remember a room has been cleared? AS3,FP - actionscript-3

Question

I have am new to AS3 and coding in general so this is why I am asking this question. I am trying to make a like semi-proceduraly generated dungeon crawler sort of thing like binding of isaac using flashbuilder and flashpunk.
but this has left me with a problem; I have figured out two ways to do the rooms. Either I can spawn all the rooms at once and have the players move between them using a door entity to block progress or I can load a new world that contains the room inside it and nothing else using FP.world = new world. But this gives me two problems so basically this is the main thing I want to know.
I want the world to remember what was in it and what was killed even if I enter a new world. E.g. right now if I enter a new world it will load that world up fresh and then if I kill all the enemies and leave and then re enter it will just spawn all the enemies again. I need to know how to get that room to remember it has been cleared of enemies.
Is there anyway to do this?

Answer 1

I'm not familiar with FP, so I cannot tell if FP allows to save room states. You better check the documentation, but if it doesn't help, you can do the following:
Find a way to get the room unique ID somehow. It could be anything - a coordinate, a number, a name, an object, etc. Just be sure it is unique. Once you have it, proceed.
The next mandatory thing you need is a way to get and set the room state. I.e. after getting state you can know that there are three goblins in a room. And setting state would be like "remove all and put these three goblins in this room". These requirements are natural as you are going to read and write the room's content anyway. Once you have it, the rest is easy.
Choose how you will keep the state. Let's say, an Object like {goblins:3, chest:1}. If you kill one goblin, it will become { goblins:2, chest:1 }. If you want to remember just the rooms that are FULLY cleared, then you simply need a boolean variable (true/false) as a state object.
You can store the state Object in a Dictionary as a key-value pair where key is the room's unique ID.
var visited_rooms:Dictionary = new Dictionary();
var roomID = ... // unique room id
var savedState:Object = { goblins:3, chest:1 } // read room state somehow
visited_rooms[roomID] = savedState;
Now, upon leaving the room, you get the state info and put it in the Dictionary.
Once you enter this room again, just check if its unique ID is present in the Dictionary and restore the state if so:
var roomID = ... // unique room id
if (roomID in visited_rooms) {
var savedState:Object = visited_rooms[roomID];
room.setState(savedState);
}
That's basically all.