Using 'File' to save scene object locations to rebuild later in AS3

Question

I am attempting to use the \'File\' function in ActionScript 3 to save the following information:

I have varying draggable display objects in the scene, the amount a

Answer 1

Assuming all your objects to save belong to the same parent, you could dosomething along these lines:

First, create a class file (let's call is SaveData.as and put it in the root of your project directory). This will describe the data you want to save:

package 
{
    import flash.geom.Rectangle;

    public class SaveData 
    {
        public var bounds:Rectangle; //to save where an object is on the stage
        public var classType:Class; //to save what kind of object it is

        //you could add in more proterties, like rotation etc


        public function SaveData() {

        }
    }
}

Next, on your save function, do something like this:

    //this will hold all your data
    //a vector is the same as an array only all members must be of the specified type
    var itemList:Vector. = new Vector.();

    //populate the array/vector with all the children of itemContainer
    var tmpItem:SaveData;
    //loop through all children of item container
    for (var i:int = 0; i < itemContainer.numChildren; i++) {
        tmpItem = new SaveData(); //create a new save record for this object
        tmpItem.bounds = itemContainer.getChildAt(i).getBounds(itemContainer); //save it's bounds
        tmpItem.classType = getDefinitionByName(itemContainer.getChildAt(i)) as Class; //save it's type
        itemList.push(tmpItem);  //add it to the array
    }

    //Now you have an array describing all the item on screen

    //to automatically serialize/unserialize, you need this line (and you need to register every class nested in SaveData that isn't a primitive type - which would just be Rectangle in this case
    registerClassAlias("SaveData", SaveData);
    registerClassAlias("flash.geom.Rectangle", Rectangle);

    //create a new File to work with
    var file:File = File.applicationStorageDirectory; //or whatever directory you want
    file.resolvePath("saveData.data"); //or whatever you want to call it
    var fileStream:FileStream = new FileStream();
    fileStream.open(file, FileMode.WRITE);
    fileStream.writeObject(itemList); //write the array to this file
    fileStream.close();

---

Now, to load it back in:

    var itemContainer:Sprite = new Sprite(); //however you initialize this
    addChild(itemContainer);

    var file:File = File.applicationStorageDirectory;
    file.resolvePath("saveData.data");
    var fileStream:FileStream = new FileStream();
    fileStream.open(file, FileMode.READ);
    var itemList:Vector. = fileStream.readObject() as Vector.;
    fileStream.close();

    //now that you've read in the array of all items from before, you need to recreate them:
    var tmpItem:DisplayObject;
    var tmpClass:Class;
    //loop through all items in the array, and create a object
    for (var i:int = 0; i < itemList.length; i++) {
        tmpClass = itemList[i].classType; //The type of item
        tmpItem = new tmpClass() as DisplayObject; //create the item

        //now move the item to it's former position and scale
        tmpItem.x = itemList[i].x;
        tmpItem.y = itemList[i].y;
        tmpItem.width = itemList[i].width;
        tmpItem.height = itemList[i].height;

        //add the item back to the parent
        itemContainer.addChild(tmpItem);
    }

If you're not sure of the imports, here they are:

import flash.filesystem.File;
import flash.filesystem.FileMode;
import flash.filesystem.FileStream;
import flash.net.registerClassAlias;
import flash.utils.getDefinitionByName;
import flash.utils.getQualifiedClassName;