Re: dealing with javascript

[Andor Demarteau <ademarte@students.cs.uu.nl>]

On Thu, 23 May 2002, T. V. Raman wrote:
hi,
 > Basically Javascript of interest does one of 3 things:
 > 
 > 0) generate content (document.write )
 > 1) Provides an event handler e.g. for mouse rollovers etc
 > --the only handler that is really of interest is the one on
 > form submit and anchor clicks (href="javascript:")
yes, and the one where other menys are chagned whena  selection in a meny
is made.
Like you select a movie and another meny wiill change to the availabel
theaters where it is showing.
This ofcourse does some calls to teh server as well.
These are the more tricky parts.

 > 2) These handlers typically show up as JS functions written
 > by the site author -- and eventually end up calling
 > window.open or something equivalent  like
 > document.location="url"
indeed, some like the javascript() once can mostly simply be rewritten
using the page it's baseurl and appending the url in the js() link.


 > You can handle all of these by essentially running the HTML
 > page through a JS interpreter and telling the interpreter to
 > produce HTML with the JS code evaluated 
 > and results spliced back in as HTML.
How about ssl-stuff, your proxy needs essentially to understand ssl as
well.

 > Look at rhino.jar for a full JS implementation in Java
 > --take rhino.jar and write yourself the above interpreter
 > --if you dont like Java pick your favorite language.
Java is to slow for this, specialy on heavyloaded machines or haevily
loaded proxy-systems.
Perl should be easier causei it's made to handel text in/output

 > Finally hook the "interpreter" above 
 > into a proxy server and test it.
 > the proxy server should run JS enabled WWW pages through
 > your interpreter.
maybe easier to write a small proxy yourself then to say edit the
squid-proxy to do this.

 > If you build this it will work for all browsers.
ture.

 > >>>>> "RAYNER" == RAYNER Peter <peter.rayner@csiro.au> writes:
 > 
 >     RAYNER> I guess we're all running into problems with
 >     RAYNER> javascript more and more often.  I'm wondering
 >     RAYNER> if it's time to put some collective effort into
 >     RAYNER> a solution and, if so, what it might be.  The
 >     RAYNER> last time this topic turned up on the emacs-w3
 >     RAYNER> list, Bill Perry's suggestion was for some kind
 >     RAYNER> of external parser, rather than extending the
 >     RAYNER> capabilities of emacs-w3 itself.  The other
 >     RAYNER> alternatives I see are to wait and hope the
 >     RAYNER> netscape accessibility efforts make the problem
 >     RAYNER> go away or to extend the capabilities of some
 >     RAYNER> other access tool.  Does anyone have any
 >     RAYNER> suggestions for which alternative might be
 >     RAYNER> preferable?  If we do decide on an external
 >     RAYNER> filter what kinds of capabilities must it have?
 >     RAYNER> The few times I've looked inside inaccessible
 >     RAYNER> pages the JS seems to be doing uninteresting
 >     RAYNER> things like drop-down lists which could easily
 >     RAYNER> be handled other ways.  But I don't know enough
 >     RAYNER> about the capabilities of javascript to know
 >     RAYNER> what other kinds of events we might have to deal
 >     RAYNER> with.  I'm happy to try and hack something
 >     RAYNER> together to do this provided there's a
 >     RAYNER> reasonable chance of success; it's about time I
 >     RAYNER> brushed up my perl anyway.  There also look to
 >     RAYNER> be some open-source implementations of
 >     RAYNER> interpretters out there we could possibly modify
 >     RAYNER> for the task.  So do people have a view of
 >     RAYNER> whether and how to go forward with this?  Any
 >     RAYNER> currently active projects?  Other comments
 >     RAYNER> cheers Peter Rayner
 > 
 > 
 > 
 >     RAYNER> _______________________________________________
 >     RAYNER> Blinux-list mailing list Blinux-list@redhat.com
 >     RAYNER> https://listman.redhat.com/mailman/listinfo/blinux-list
 > 
 > 

-- 
slainte mhaith (good health), slainte (cheers)
Uisce Beatha (water of live/health)
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Andor Demarteau                 E-mail: ademarte@students.cs.uu.nl
student computer science        www: http://www.students.cs.uu.nl/~ademarte/
Utrecht University              irc: see webpage for details
-----------
Believe in yourself, know what you want, and make it happen!