I’m currently creating a movie that has a real time reflection of the images loaded. Loading the images twice feels incredibly stupid and costs a load of bandwidth…

:-/

Wow, good catch! ActionScript 3.0 might have a way around this, but I believe you’re right: in AS2, loaded external content, such as a JPG, almost certainly would not “clone” in the sense discussed above. I can’t think of a way to check if external content has even been loaded, so this may be the one final obstacle that keeps AS2 object cloning almost, but not quite, an achievable goal.

resetRefs();
for (var prop:String in target) {
if(target._parent[newName][prop] == undefined){
target._parent[newName][prop] = copyMe(target[prop]);
}
}

My new code will keep “pointers” intact, e.g.:

resetRefs();
o = {};
o.a = new Date();
o.b = o.a;
o.c = new Date();
trace(’a: ‘+o.a); // these 3
trace(’b: ‘+o.b); // all show up
trace(’c: ‘+o.c); // the same
p = copyMe(o);
p.a.setTime(0);
trace(’a: ‘+p.a); // only this
trace(’b: ‘+p.b); // and this are the same
trace(’c: ‘+p.c); // this value didn’t change

Here is the necessary code to make this all work:

Array.prototype.indexOf = function(x){
for(var y in this){
if(this[y] === x){
return y;
}
}
return -1;
};
function resetRefs(){
_global.refs = [];
_global.dups = [];
}
function copyMe(obj) {
var n = {};
var i = _global.refs.indexOf(obj);
if(i!=-1){
return _global.dups[i];
}else{
if (obj == undefined || obj == null) {
return obj;
} else if (obj instanceof String || typeof (obj) == ’string’) {
n = (obj === obj.valueOf()) ? obj : new String(obj.valueOf());
} else if (obj instanceof Number || typeof (obj) == ‘number’) {
n = (obj === obj.valueOf()) ? obj : new Number(obj.valueOf());
} else if (obj instanceof Boolean || typeof (obj) == ‘boolean’) {
n = (obj === obj.valueOf()) ? obj : new Boolean(obj.valueOf());
} else if (obj instanceof Date) {
n = new Date(obj.valueOf());
} else if (obj instanceof Array) {
n = obj.slice();
} else if (obj instanceof Error) {
n = new Error();
}
if (obj instanceof MovieClip || obj instanceof Button || obj instanceof TextField) {
n = obj;
} else {
for (var x in obj) {
n[x] = copyMe(obj[x]);
}
}
_global.refs.push(obj);
_global.dups.push(n);
return n;
}
}

To fix your code, just change the line in the for loop:

target._parent[newName][prop] = copyMe(target[prop]);

The problem with copying is that when a property includes a reference to a clipC (say within clipA) and then you clone clipA to clipB. Should the reference to clipC be the one in clipA or the duplicated one in clipB?

Also, say clipA has a non primitive variable, A, and a pointer to it, B. When you clone, how will the code know that B should point to the duplicated A, and not make a clone of A and another of clone of A in B. My code will do the latter. Just like in real life, can cloning really be perfected???

Here’s my copyMe function… (hasn’t been tested completely though!)

function copyMe(obj) {
var n = {};
if(obj == undefined || obj == null){
return obj;
}else if (obj instanceof String || typeof (obj) == ’string’) {
n = (obj === obj.valueOf()) ? obj : new String(obj.valueOf());
} else if (obj instanceof Number || typeof (obj) == ‘number’) {
n = (obj === obj.valueOf()) ? obj : new Number(obj.valueOf());
} else if (obj instanceof Boolean || typeof (obj) == ‘boolean’) {
n = (obj === obj.valueOf()) ? obj : new Boolean(obj.valueOf());
} else if (obj instanceof Date) {
n = new Date(obj.valueOf());
} else if (obj instanceof Array) {
n = obj.slice();
} else if (obj instanceof Error) {
n = new Error();
}
if (obj instanceof MovieClip || obj instanceof Button || obj instanceof TextField) {
n = obj;
} else {
for (var x in obj) {
n[x] = copyMe(obj[x]);
}
}
return n;
}

You bring up a good point. Sure enough, you’re right — and, of course, your passed-by-reference observation makes perfect sense. That said, the MovieClip instance is, I maintain, indeed cloned: the original points to an object by reference (here, an array), and the clone points to the same object by reference.

Here again, what we mean by “clone” is kind of a cheat, isn’t it? We want a conceptual clone, not an actual one. We want cloned movie clips with cloned composite (non-primitive) properties.

Your comment has me thinking. If you figure something out, please post again. I’ll do the same.

ok, so we “cloned” it right? i have discovered that the two are very much still linked together. for instance….AFTER cloning, add in the line:
originalClip.souvenirs[1] = “CHANGED”;
then print them BOTH out. you see that they BOTH changed.

now i have had enough programming to know what is going on here. any variable is passed by reference unless it is a primitive data type (int, string, etc); objects, arrays, movieclips, etc are all passed by reference. in other words…..there is still only ONE “souvenirs” array, it is stored on the originalClip and the newClip has a pointer to that.

so my question is this…..how do we REALLY clone something? still has yet to be determined…..i have played around with some pretty intense recursive functions that check to see if it is a primitive type or not, if it is not then it needs to create a new object, and go recursively copy all of it’s primitives as well. i don’t know if this makes sense, and i haven’t really done it in depthly yet.

i will post the solution if i ever have the time to figure it out, in the mean time….anyone else? what do you think David?