Re: Support for javascript: scheme in libwww

Andrew Cassin (acas@catt.rmit.edu.au)
Wed, 3 Sep 1997 17:27:52 +1000 (EST) 

JR Beaman writes on the use of javascript:
> Real-time activity, like calculations, and displays dependant on
> operator input.  How about Field validation?  ie. Enter a valid number.
> Shopping cart sub-totals, and totals too.  Etc, etc.

Hmmm... client side computation -- fair enough. 
Field validation is a bit dubious to my mind, you should
always do that in such a way as to guarantee integrity of your database, 
one day someone will have robots and these robots will issue the
necessary commands to register with your database directly so you must
check at this point as well as elsewhere. I agree that this allows 
users to catch simple errors before burdening the server tho'

> > Or has it turned off for security reasons (which is what I do)?
> 
> What security problems have you experienced with JavaScript on?
> I would really like to know (as might our readers).

Comp.risks contains numerous articles relating to javascript vulnerabilities.
Interested readers can access the form at 

http://catless.ncl.ac.uk/Risks/search.html

and search for 'javascript' as a starting point.

> Try shockwave or even MIDI on your "professional" pages and see how many 
> potential customers go running away...  And yet we are "advised" to use
> them?

Bury javascript in your pages and watch me go elsewhere... :-)

> Animated Gifs can cause browser crashes, as well as many other
> multimedia objects.  

Really? They dont crash for me -- my main objection to movies is the
distracting and often moronic way they are used.

> I snicker at your comment (not at you) that it could be tackled in many
> ways.

One way without using javascript to update a frame automatically is to
put meta-information on the page telling the browser to refresh the page 
every so often. Suitable for stock quotes. The META tag is
used to specify the refresh rate. A java applet could also be used. 

> P.S. When is HTML going to get an "INCLUDE" function (same as "REQUIRE")
> so we don't have to write the same freekin code over and over, and spend
> all day updating some little thing on hundreds of pages?  

You might want to look at CSS (Cascading Style Sheets) refer to www.w3.org
for more info or perhaps something like the perl website maintenance
toolsuite WML which is available at http://www.engelschall.com/sw/wml/

ACAS