[georss] [OpenLayers-Users] GeoRSS and layers

[Mikel Maron]

Hi Yves

Yes, both "GeoRSS" and "MediaRSS" are namespaces for focused extensions to RSS feeds.
I think it's a good idea to reuse existing standards and conventions when appropriate and easy,
and in worldKit, GeoRSS and elements of MediaRSS are used to do just what you intend.
And "category" seems a good analogy to layer.

The SVG comment was kind of offhand and not thought through. Really I was only particularly thinking
of the styling properties of SVG .. http://www.w3.org/TR/SVG11/styling.html .. which more or less
covers the kind of things in SLD.

With worldKit, the needs for styling (which is accomplished through a seperate xml config file) have been
basically (circle, square, triangle) scale, linestyle, color, alpha, & thickness. That group of styles is
"lightweight" .. easy to understand and implement.

Perhaps CSS is appropriate for specifying styling information for GeoRSS. Lots of issues there, but I
quite like that direction.

Mikel

----- Original Message ----
From: Yves Jacolin <yjacolin at free.fr>
To: Mikel Maron <mikel_maron at yahoo.com>
Cc: Christopher Schmidt <crschmidt at metacarta.com>; georss at lists.eogeo.org
Sent: Monday, January 15, 2007 9:15:35 PM
Subject: Re: [georss] [OpenLayers-Users] GeoRSS and layers

Hi,

I am the user who sent the question to the OL list. I did not manage geoRSS 
and all other things link to this. ;-)

What I would like to do first, was just trying to manage icon using GeoRSS. 
But, I used only point feature so a picture file could be great (but only for 
my own purpose). For a more general dev, It would be great to manage for all 
other feature type. So my first attempt is closer to the solution gave by 
Christopher Schmidt. But I did not know if I could add some custom tags. The 
answer is not, but it seems we could use another space name (am I right about 
the term ?) inside GeoRSS XML file.

SVG seems quiet difficult, not really handy. But it will surely nicer and 
smaller than a picture file ;-)

Thanks you for your answer !

Y.
Le Lundi 15 Janvier 2007 21:51, Mikel Maron a écrit :
> Your first email included quotes from an OpenLayers user looking to specify
> an icon within a GeoRSS feed, and that's exactly what I've addressed, never
> suggesting that MediaRSS was appropriate for anything beyond that. So yes,
> you are confused.
>
> For an extensible styling solution, I'd prefer to start from SVG.
>
>
>
> ----- Original Message ----
> From: Christopher Schmidt <crschmidt at metacarta.com>
> To: Mikel Maron <mikel_maron at yahoo.com>
> Cc: georss at lists.eogeo.org; Yves Jacolin <yjacolin at free.fr>
> Sent: Monday, January 15, 2007 8:34:32 PM
> Subject: Re: [georss] [OpenLayers-Users] GeoRSS and layers
>
> On Mon, Jan 15, 2007 at 08:37:50AM -0800, Mikel Maron wrote:
> > For icons, worldKit uses the MediaRSS namespace.
> > http://search.yahoo.com/mrss This is the defacto media syndication
> > format, and is used by flickr, among others. For mapping icons, worldkit
> > uses media:thumbnail.
> >
> > http://worldkit.org/doc/rss.php#thumb
>
> Perhaps I'm confused, but there are a lot more things to think about
> than a thumbnail icon. Describing representation of geographic
> information requires describing things like stroke (color, width,
> outline), etc. This is what SLD is designed for, and part of what KML
> contains. KML contains additional pieces to also describe the
> geographic features, a role which GeoRSS performs on its own, but the
> styling/symbolization of geographic features is not something that seems
> to fit inside the Yahoo! Media RSS namespace.
>
> Essentially, so far as I can see it, there are two useful options:
>  * Define a subset of SLD, and use that to describe rendering
>    information.
>  * Define a subset of KML style descriptors, and use that to describe
>    rendering information.
>
> The use of media:thumbnail is fine for single points, but GeoRSS has
> support for more than that, and ignoring the other geometry types over
> a points-only approach seems like a mistake.
>
> A simple chunk of KML to describe an Icon Style is:
>
> <Style id="rel1.0">
> <IconStyle>
>   <Icon>
>     <href>http://developers.metacarta.com/img/symbols/mc1.0.png</href>
>   </Icon>
> </IconStyle>
> </Style>
>
> It would probably be possible to include something similar in a GeoRSS
> feed:
>
> <rss xmlns:kml="http://earth.google.com/kml/2.0";; xmlns:georss="foo">
> <item>
>   <georss:point></georss:point>
>   <kml:Icon>
>     <kml:href>foo</kml:href>
>   </kml:Icon>
> </item>
>
> At the same time, more complex Styling information can also be included,
> when needed, preventing the need for a non-extensible ad-hoc solution.
>
> I don't have enough use cases for GeoRSS that I have a desire to
> champion a particular decision here, but I strongly encourage anyone
> thinking about this to consider existing standards for geographic data
> styling in the discussions.
>
> Regards,

-- 
Yves Jacolin
-------------
http://yjacolin.gloobe.org
http://softlibre.gloobe.org