[mapserver-users] XML mapfile?

Mike Haarman mhaarma at socsci.umn.edu
Wed May 22 15:41:57 EDT 2002 

Correct me, please, but I don't think anyone is advocating throwing out
the current format.  The desire is to support additional functionality for
those of us for whom the cost/benefit ratio makes sense.

Mike

On Wed, 22 May 2002 imap at chesapeake.net wrote:

>
> yah.. *please* dont break the native mapfile format...
> upgrades are painful enough without completely overhauling
> the mapfile to a new format.  Some backward compatibilty
> would be apprecitated.
>
> Regards,
>
> Chris Stuber (mapsurfer)
> Silicon Mapping Solutions, Inc.
>
> Steve Lime wrote:
> >
> > Ok, you're a whiner. <g>
> >
> > This is being looked into. There are other competing priorities at the
> > moment so it's down
> > the list a bit right now. My plan would be to support both native and
> > XML-based configuration
> > in the short term until some of the performance issues could be dealt
> > with. One could actually
> > make MapServer read XML with just a few tweaks of the lexer, and since
> > you wouldn't validate
> > at that point anyway...
> >
> > I'd like to see the conversation continue, perhaps off list with a
> > smaller group. Some practical
> > demonstrations of the benefits of an XML-based config file might also
> > help those of us not
> > experienced with XML see the light.
> >
> > Steve
> >
> > Stephen Lime
> > Data & Applications Manager
> >
> > Minnesota DNR
> > 500 Lafayette Road
> > St. Paul, MN 55155
> > 651-297-2937
> >
> > >>> "C F" <gis_consultant at hotmail.com> 05/22/02 10:51AM >>>
> > I hear you on the performance concerns.  However, I think we could get
> >
> > around that by serializing the XML DOM object into a file (that's how
> > ArcIMS
> > does it.... which probably hurts my case more than anything).  Then the
> > only
> > time the XML file would be parsed is in the first request after a
> > change to
> > it is made (done by using file's timestamps).  Who knows, it might even
> > be
> > fast than the current implementation.  I don't really know if that's
> > true as
> > I have not actually used serialized DOM files in my own apps... but it
> > makes
> > sense to me that it could possibly alleviate your performance
> > concerns.
> > Now, assuming that performance wasn't an issue, I still hear concerns
> > about
> > simplicity.  In raw text-edit mode, there's nothing that can be done
> > about
> > that.  I consider it a very minor difference... but that's just a
> > matter of
> > taste and there will never be a consensus on that.  All I can say about
> > that
> > is that XML would make it tremendously easier for people to write
> > mapfile
> > generation/editing tools.... also for people writing tools to batch
> > update
> > their mapfiles, etc.  In other words, with maybe the very minor
> > exception of
> > manual text editing, it would make them much easier to handle.... again
> > a
> > maybe matter of taste :)
> > MapScript is a solution... but may not be a solution for everyone if
> > they
> > want to build a more of a single, cross-platform solution with minimum
> >
> > modification and customization to the servers involved.  Also, the fact
> > that
> > we'd gain access to this important mapfile information without the need
> > for
> > "programming" would be nice.  I envision this would be set up in much
> > the
> > same way it is now, only with XSLT templates replacing the current form
> > of
> > templates.
> >
> > Well those are my thoughts.... but I haven't really received any
> > positive
> > feedback since my original post so it looks I'm all alone :)  People
> > seem to
> > be comfortable with the current format.  Or maybe I'm just looking at
> > it for
> > use in different uses than it has traditionally been used for.  I think
> >
> > everybody that's worked on it has done an *awesome* job.  I think the
> > product is great, just call me a whiner if you'd like :)  Paul Ramsey's
> > idea
> > of out we could have it both ways is something I might do for myself
> > anyway.
> >   If there is ever enough interest in it maybe that's somewhere I can
> > contribute to the project.
> >
> > >From: Daniel Morissette <morissette at dmsolutions.ca>
> > >To: C F <gis_consultant at hotmail.com>
> > >CC: mapserver-users at lists.gis.umn.edu
> > >Subject: Re: [mapserver-users] XML mapfile?
> > >Date: Wed, 22 May 2002 08:19:31 -0400
> > >
> > >I think that Steve has been considering a switch to XML eventually,
> > but
> > >I don't think there is any formal plan.
> > >
> > >I agree that XML might give more flexibility to the user by allowing
> > him
> > >to read the mapfile from external tools, but it would be at the cost
> > of
> > >performance (i.e. speed) when parsing the mapfile for every request.
> > >Combine this loss of performance with the fact that XML would be
> > harder
> > >to edit manually than the current format, and you know where I stand
> > >personally.
> > >
> > >I'm not saying that if we were redesigning from scratch I wouldn't
> > >consider XML (we use it a lot in other apps), but since we've already
> > >got a very good (fast and simple) mapfile format then I won't be the
> > one
> > >initiating a switch to XML mapfiles.
> > >
> > >Note that MapScript already gives you access to almost every piece of
> > >information from the mapfile, so when the CGI cannot do what you need
> > >then the logic path is to switch to MapScript, and then sky is the
> > >limit.
> > >
> > >My 0.02$
> > >--
> > >------------------------------------------------------------
> > >  Daniel Morissette               morissette at dmsolutions.ca
> > >  DM Solutions Group              http://www.dmsolutions.ca/
> > >------------------------------------------------------------
> > >   Don't put for tomorrow what you can do today, because if
> > >       you enjoy it today you can do it again tomorrow.
> >
> > _________________________________________________________________
> > MSN Photos is the easiest way to share and print your photos:
> > http://photos.msn.com/support/worldwide.aspx
>

----------------------------------------------------------------
Mike Haarman                        Minnesota Population Center,
mhaarma at socsci.umn.edu              University of Minnesota,
                                    537 Heller Hall,
                                    Minneapolis, MN 55455
Co-Architect, Programmer,
  National Historical GIS -- http://www.nhgis.org/
Maintainer,
  DDI Codebook DTD -- http://www.icpsr.umich.edu/DDI/

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