node object gets clobbered after clone

[Richard Trahan]

I'm a js newbie, and I'm sure I'm missing something; please help me
find it.

Consider these fragments:

function reconstruct_select_node(selectnode,nodearray) {
alert("120: "+typeof(selectnode));
newselnode = selectnode.cloneNode(false); // shallow clone
... (operations only on newselnode)
alert("139: "+typeof(selectnode));
return newselnode;
}
....
ar = new Object();
ar.selectgraphsnode = (some node object)
....
alert("405: " + typeof(ar.selectgraphsnode));
newselnode = reconstruct_select_node(ar.selectgraphsnode,sna);
alert("407: " + typeof(ar.selectgraphsnode));

The alerts at lines 120, 139, and 405 report type "Object", but
the alert at line 407 is "undefined".

I have an easy workaround for this, but I'd like to understand
what is happening.

Any help, please. Thanks.

 

[Lasse Reichstein Nielsen]

function reconstruct_select_node(selectnode,nodearray) {
alert("120: "+typeof(selectnode));
newselnode = selectnode.cloneNode(false); // shallow clone

Notice that "newselnode" is not declared as a local variable, so it
is created as a global one. That is probably not your intent (no
need to return it in that case), so you might vant to add "var" in
front of "newselnode" here.

... (operations only on newselnode)

They don't affect "ar"?

alert("139: "+typeof(selectnode));
return newselnode;
}
...
ar = new Object();
ar.selectgraphsnode = (some node object)
...
alert("405: " + typeof(ar.selectgraphsnode));
newselnode = reconstruct_select_node(ar.selectgraphsnode,sna);

What is "sna"'s value?

alert("407: " + typeof(ar.selectgraphsnode));

The alerts at lines 120, 139, and 405 report type "Object", but
the alert at line 407 is "undefined".

Try alerting the type of "ar.selectgraphsnode" at line 102 and 139
as well.

I have an easy workaround for this, but I'd like to understand
what is happening.

So would I, but you have to supply more code. Obviously, something
goes wrong somewhere, and I'll bet it's in the code we cannot see.
If you have a page that exhibits the problem, give us a link.

Good luck.
/L