Loop movie, but load XML once

Question

Background:
I am tasked with building a vertical news scroller that reads
from an xml file and loops indefinitely.
Problem 1:
I have figured out how to scroll static text and I am now
working on loading the xml which I also have done. The problem I am
having with loading the xml is that if the movie loops, it is
loading the XML each instance of the loop. How can I load the XML
only on the initial load and still loop the movie?
Problem 2:
When working with static text, scrolling is simply a matter
of doing a motion tween. When working with XML, the data will not
be a fixed length, so doing a motion tween will have 2 problems.
First, the original text object will have a fixed height which will
either have blank space when the XML returns less than enough to
fill it, or will have hidden text when the XML returns more that it
can hold. Can I dynamically adjust the height of a text object to
fit the text that has been put into it? Once I figure out how to
dynamically change the height we have the second problem. If the
tween was built to scroll 10 records over 200 frames and the XML
now returns 100 records, the scroll will be 10 times too fast. Can
I dynamically adjust how many frames the tween will operate
over?

Answer 1

1. You can keep the XML in a variable and use an if/else to
determine if the XML is loaded.
var myXML:XML
// later
if(!myXML){
// call function or class that loads XML and assigns loaded
XML to the variable myXML
2. You can make dynamic TextField autosized AND multilined
(autoSize and multiline text filed properties) - it will adjust
text height depending on the content - width will not be affected.
Since the scrolling is an indefinite motion in this case, I
am not sure tweening is the best approach. Perhaps a better and
more controllable solution would be to write your own function
(class) that will perform the scroll.