[FGS] Packaging Ruby Mapscript...

Robert Thau rst at alum.mit.edu
Wed Apr 5 22:56:01 EDT 2006

Hi.  Does anyone have advice for packaging something including Ruby
Mapscript as an FGS module?  I'm running into library compatibility
problems.  In particular, I have a test module which works on some
Linux systems (SuSE 10, Fedora Core 4), but not others (Debian Sarge,
FC3).  I'd ideally like to be able to build a module that works
everywhere; failing that, I'd appreciate any suggestions anyone may
have on how to ease the pain.

In case it helps, here's the current module (which just might work for you!):


The package could be briefly described as "Mapserver and PostGIS on
Rails" --- if you'd like a demo, try 


with either Firefox 1.5 (not earlier!) or IE6[*] to see it rendering
parks as mouse-sensitive, clickable polygons, pulled out of PostGIS.

Packaging details: the module contains Ruby 1.8.4, Rails 1.1, and Ruby
Mapscript.  The Ruby build seems to work cross-platform without
difficulty, and so does Rails.  Ruby Mapscript, on the other hand, is
a problem on FC3 and Sarge, because it requires more recent C++
libraries than are present on those systems.  On the other hand,
Mapscript build on FC3 fails on the more recent systems, for the
opposite reason.

FWIW, the Ruby Mapscript extension is
lib/ruby/site_ruby/1.8/i686-linux/mapscript.so in the distribution; it
was originally built in a MapServer 4.8.1 source tree in a minimally
configured system, with the package's Ruby 1.8.4 in the path.  I don't
believe Ruby itself uses C++ internally, so I think inherited
dependencies from Mapserver components (or possibly SWIG) are at issue

I'd like to avoid asking users to install new C++ libs --- though,
from recent conversation on this list, it may not be possible.

Any advice?

Thanks in advance,

Robert Thau
rst at alum.mit.edu

[*] For the technically curious: this is inline SVG in Firefox, and
    VML in IE; part of the package is libraries which render these
    graphics in whatever format the JS feature-detects think the
    browser can handle.  The displayed polygons are being simplified
    to screen resolution (PostGIS "simplify" function); clicking on
    them pulls up further explanatory text from the database.

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