SAMP and HTTPS workaround?

[Mark Taylor]

Dear SAMP users,

the problem of Web SAMP and HTTPS has been under discussion
for a while now - basically the Web Profile works fine with HTTP
but won't work from pages served using HTTPS.  A possible HTTPS-capable
profile has been prototyped, but it's pretty nasty.  There is much
more information on the topic here:

   http://andromeda.star.bristol.ac.uk/websamp/

As an alternative to the HTTPS profile, I'm thinking about more
lightweight workarounds.  One is just to provide a simple helper
application that takes a suitable filename on the command line
(VOTable table or FITS image) and sends it to a running SAMP
client.  Such an application could be associated in the
browser with suitable MIME types (application/x-votable+xml,
image/fits), or you could just choose it when the browser
asks you what application you want to open a downloaded file with.

This is much less flexible than allowing the web page (web application)
to interact with the SAMP hub itself, which is what you can do
with SAMP+Web Profile.  However, in practice, nearly(?) all Web SAMP
pages that I'm aware of just use Web SAMP to allow the user to
send a samp.load.votable or image.load.fits message, and that's
done nearly as well by the helper application.  It works with
rather than against normal browser operations, which makes it
much less painful to implement than the HTTPS profile;
it works equally with HTTPS or HTTP, and no additional 
infrastructure is required.  The main downside is that the user has 
to configure it somehow (install script, tell browser to use it 
to handle relevant files).

I have written such a helper application, and I'd be interested
to know if anyone wants to try it out: especially data providers
who are using HTTPS and want to allow users to load tables/images
using SAMP.  Would this be an acceptable solution?

You can find the application here:

   http://andromeda.star.bris.ac.uk/websamp/sampload.jar

If you run, e.g. "java -jar sampload.jar /tmp/tmpfile.vot"
then it will pop up a window asking which VOTable-capable
SAMP client you want to send tmpfile.vot to.
(It works out what kind of file it is by looking at the content).

Unless your OS/browser can execute jar files directly, to use it with
a browser you'll need to accompany it with a small shell script or 
equivalent like

   #!/bin/sh
   java -jar /path/to/sampload.jar "$@"

Any feedback, comments, ideas welcome.

Mark

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/