linked media when running on server

Richard Gaskin ambassador at fourthworld.com
Tue Nov 25 04:24:18 EST 2003


RGould8 at aol.com wrote:

> If I have a Revolution "thin client" that just has a simple "go to stack
> http://stackfromserver " type of logic, and I want that stack on the server to
> pull in images stored on the server, instead of stored within the stack, do I
> need to do something special with the pathnames to the graphics?

I've set the filename of an image to a full url with success.

When a stack is running client-side, urls as partial paths work like they do
in any other context, like local files.

But if the url begins with "http:" then it's known to be remote and the http
download happens.

FWIW, in my early RevNet tests I found it detrimental performance-wise to
use remote urls for images.  While it can make for a substantially smaller
stack file, once the stack is downloaded separate HTTP transactions have to
take place for each remote element.  Each HTTP transaction has a certain
amount of overhead setting it up, and this setup time is multiplied by the
number of remote objects.

Also, for urls already set as filenames in image objects, the image file
download occurs before the stack is drawn.  So while you save time getting
the stack over the wire, the multiple HTTP transactions may actually mean a
longer time before the stack is displayed.

Remote urls are best used for filenames in the subset of images that will
need to be changed while the stack is running.  But even then you should get
a faster overall transfer with the first visible image embedded.

Remote urls can be used sequentially for a streaming effect, in which a
stack is downloaded with empty images, and after the card is drawn a routine
steps through and sets the filename of each of those images to the
appropriate url; first you get a blank card, then an images, then another,
until the whole card is drawn.  This will likely take more time overall than
using embedded images, but if the images are large or there are a lot of
them at least the user gets to watch something more than a progress bar
during the lengthy download.  If you do any remote text elements first (a la
AOL) you're user may be so busy reading that they don't notice the long
image downloads. :)

-- 
 Richard Gaskin 
 Fourth World Media Corporation
 ___________________________________________________________
 Ambassador at FourthWorld.com       http://www.FourthWorld.com
 Tel: 323-225-3717                       AIM: FourthWorldInc



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