Difference between revisions of "geo"

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<h1> geo </h1>
'''geo''' (pronounced "gee-oh") is a simple format for marking up [http://en.wikipedia.org/wiki/WGS84 WGS84] geographic coordinates (latitude; longitude), suitable for embedding in (X)HTML, Atom, RSS, and arbitrary XML. '''geo''' is a 1:1 representation of the "geo" property in the vCard standard ([http://www.ietf.org/rfc/rfc2426.txt RFC2426]) in XHTML, one of several open [[microformats|microformat]] standards.
== Draft Specification ==
: [http://tantek.com/ Tantek Çelik] ([http://technorati.com Technorati, Inc.])
=== Copyright ===
Per the public domain release on [[User:Tantek|my user page]], this specification is released into the public domain.
=== Patents ===
=== Inspiration and Acknowledgments ===
Thanks to everyone who participated in the [[geo-bof-2005-06-30|Geo Microformat BOF at O'Reilly's Where 2.0 conference]], and in particular to [http://radar.oreilly.com/nat/ Nat Torkington] and Vee McMillen of [http://oreilly.com O'Reilly] for [http://conferences.oreillynet.com/cs/where2005/view/e_sess/7476 arranging and hosting the BOF].  Thanks to Chris Hibbbert for providing the [http://www.geocaching.com/seek/cache_details.aspx?guid=dc4754bf-64d5-4f28-8715-45ad2505c86f real world geo-caching example].
== Introduction and Background ==
The vCard standard ([http://www.ietf.org/rfc/rfc2426.txt RFC2426]), has been broadly and interoperably implemented (e.g. Apple's Address Book application). The [[hcard|hCard]] microformat has similarly received significant adoption, from numerous sites publishing the format, to hCard to vCard proxies, to clientside javascript parsers.
At the [http://conferences.oreillynet.com/where/ Where 2.0 conference] in June 2005, there was widespread recognition that the community needed a way to simply and easily publish visible, extractable, geographic location information on the Web, given how often bloggers, and numerous other sites publish such information.  The [[geo-bof-2005-06-30|geo microformat BOF]] discussed this very topic, and concluded with a consensus decision to just try using ''geo'' from vCard/hCard.
This specification introduces the '''geo''' microformat, which is a 1:1 representation of the aforementioned ''geo'' property from the vCard standard, by simply reusing the ''geo'' property and sub-properties as-is from the [[hcard|hCard]] microformat.
Publishers can both embed '''geo''' addresses directly in their web pages and feeds, as well as markup existing latitude/longitude coordinates in the context of the rest of the information in their web pages and feeds.
If the publisher knows and is publishing the ''name'' of the location in addition to its geo lat/long, then the publisher {{must}} use [[hcard|hCard]] instead of just '''geo''' to publish the name and geo lat/long of the location.
If the publisher knows and is publishing the address of the location, OR if the address of the location was what was actually entered by a human, and the publisher simply turned that into lat/long using some sort of a service, then the publisher {{should}} use [[adr]] to publish the actual human entered address information since that communicates far more semantic information than a simple geo lat/long coordinate.
== Semantic XHTML Design Principles ==
== Format ==
=== Singular Properties ===
Note that all the properties in '''geo''' are singular properties, and thus the first descendant element with that class should take effect, any others being ignored.
=== Human vs. Machine readable ===
If an <code>&lt;abbr&gt;</code> element is used for a property, then the <code>title</code> attribute of the <code>&lt;abbr&gt;</code> element is the value of the property, instead of the contents of the element, which instead provide a human presentable version of the value.
=== Value excerpting ===
Sometimes only part of an element which is the equivalent for a property should be used for the value of the property. For this purpose, the special class name <code>value</code> is used to excerpt out the subset of the element that is  the value of the property.  See [[hcard|hCard]] for details on this.
=== Root Class Name ===
The root class name for an geo location is <code>geo</code>.
=== Property List ===
This is the list of properties in geo, taken from [[hcard|hCard]]:
* latitude
* longitude
=== XMDP Profile ===
See [[hcard-profile]] for the [http://gmpg.org/xmdp XMDP] profile of hCard which contains the above complete list of properties, with references to their RFC 2426 definitions.
=== Parsing Details ===
See [[hcard-parsing|hCard parsing]], with the only difference being that "geo" is the root class name, rather than "vcard".
== Examples ==
This section is informative.
=== Example from RFC2426 ===
Section 3.4.2 of RFC2426 has a simple geo example:
this vCard fragment as a geo, as [http://microformats.org/wiki/hcard-examples#3.4.2_GEO_Type_Definition first documented on the hCard examples page]:
<div class="geo">GEO:
<span class="latitude">37.386013</span>,
<span class="longitude">-122.082932</span>
this geo could be displayed as: <!-- this section includes a live Geo microforamt - please edit with care -->
<div class="geo">GEO: <span class="latitude">37.386013</span>, <span class="longitude">-122.082932</span></div>
Note that this is a '''live''' geo microformat, which will be found on this page by parsers.
=== Real world geo example ===
Here is a sample of published lat/long info (from [http://www.geocaching.com/seek/cache_details.aspx?guid=dc4754bf-64d5-4f28-8715-45ad2505c86f geocaching: Noble Steed]):
N 37° 24.491 W 122° 08.313
With geo markup:
<div class="geo">
<abbr class="latitude" title="37.408183">N 37° 24.491</abbr>
<abbr class="longitude" title="-122.13855">W 122° 08.313</abbr>
This geo might be displayed as: <!-- this section includes a live Geo microforamt - please edit with care -->
<div class="geo"><abbr class="latitude" title="37.408183">N 37° 24.491</abbr> <abbr class="longitude" title="-122.13855">W 122° 08.313</abbr>
Again, this is a '''live''' example.
Note that since the real world example used a more human readable presentation of the geo coordinates, we use the [[abbr-design-pattern]] to keep that more human readable presentation, and in addition provide the respective absolute numerical values for the geo.
== Examples in the wild ==
This section is '''informative'''. The number of Geo examples in the wild has expanded far beyond the capacity of being kept inline in this specification. They have been moved to a separate page, [[geo-examples-in-wild|Geo examples in the wild]].
== Implementations ==
This section is '''informative'''.
The following implementations have been developed which either generate or parse geos outside the context of hCards. If you have an geo implementation, feel free to add it to the '''top''' of this list. Once the list grows too big, we'll make a separate wiki page.
*I've added Geo mark-up to the output of Wikipedia's [http://en.wikipedia.org/wiki/Template:GeoTemplate GeoTemplate] which is called by '''many thousands''' of other Wikipedia pages. Example: the coordinates (top right) in [http://en.wikipedia.org/wiki/Great_Barr] link to [http://tools.wikimedia.de/~magnus/geo/geohack.php?params=52.54833_N_1.93212_W_region:GB_source:enwiki-osgb36(SP047945)]; the latter now has Geo mark-up in the "[http://tools.wikimedia.de/~magnus/geo/geohack.php?params=52.686_N_2.193_W_region:GB_type:landmark#Mark-up Mark-up]" section. [[User:AndyMabbett|Andy Mabbett]] 03:10, 13 Jul 2007 (PDT)
*GIS-Wiki's "[http://www.giswiki.org/hjl_get_CoorE.htm hjl_getCoor]" now outputs Geo markup, from a Google Maps API.
*[http://www.addressfix.com/ AddressFix] takes any valid address in the listed countries (as at 2003-07) or map point (using GoogleMaps API) and outputs geo markup.
**Countries: Andorra, Australia, Austria, Belgium, Canada, France, Germany, Gibraltar, Italy, Japan (but only in Japanese), Liechtenstein, Luxembourg, Monaco, Netherlands, New Zealand, San Marino, Spain, Sweden, Switzerland, United States of America and the Vatican City.
**For countries other than the UK, the British Isles and China it provides geocoding for country names and city names (e.g. "Nairobi, Kenya").
**For UK, the British Isles and China, Google returns an error.
* [http://code.highearthorbit.com/greaseroute/index.php GreaseRoute] is a GreaseMonkey user script (also available as a simple Firefox Extension) which will add icons for displaying the MapQuest map of a [[geo]]. Written by [http://highearthorbit.com Andrew Turner]
* [http://www.podster.de/page/geotest podster.de] finds geo markups in podcast RSS Feeds and maps soundseeing episodes on a map (German only)
* [http://blog.codeeg.com/ Calvin Yu] has written a  [http://blog.codeeg.com/2006/01/28/using-microformats-to-plot-my-favorite-places/ web service that will allow you plot and describe places on a Yahoo Map easily] using [[hreview|hReview]] and [[geo]].
* [http://bluesmoon.blogspot.com/ Philip Tellis] has written a [http://bluesmoon.blogspot.com/2006/01/of-microformats-and-geocoding.html javascript to add maps to geo markup on pages]
* [http://placenamehere.com/TXP/pnh_mf/ pnh_mf] is a plugin for [http://textpattern.com/ Textpattern] that supports embedding geos and other microformats in templates and blog posts. Written by [http://placenamehere.com/ Chris Casciano].
* [http://bluesmoon.blogspot.com/ Philip Tellis] has written some javascript to [http://bluesmoon.blogspot.com/2006/01/of-microformats-and-geocoding.html convert the geo microformat to a google map] using [[geo]].
* Brian Suda has written some [http://suda.co.uk/projects/microformats/geo/ geo extracting] code to convert geo microformats to KML for use with Google Maps and Google Earth. There is also a bookmarklet to extract the data and pass it to google maps automatically. He is working on a GeoRSS version for Yahoo! Maps as well.
**GPX export is done, but needs some tweaking and testing. Just change &type=(kml|georss|gpx). Not quite ready for primetime yet. Feel free to test and send feedback.
* Fil explains [http://www.jquery.info/spip.php?article7 how to use the geo microformat with the javascript library jQuery] [http://jquery.com].
* [http://georss.org/geopress GeoPress] is a WordPress (http://wordpress.org) plugin that supports embedding adrs, geo, maps (dynamically switchable between Google-Yahoo-Microsoft Maps), and GeoRSS (http://georss.org) feeds. Written by [http://highearthorbit.com Andrew Turner]
* [http://www.openstreetmap.org OpenStreetMap] uses the geo microformat on its wiki for place pages (added by [http://wiki.openstreetmap.org/index.php/User:Pigsonthewing Andy Mabbett]) and also on the GPS trace pages and diary entry pages ([http://www.dankarran.com/blog/archives/2007/09/04/pinpoint_your_openstreetmap_diary_entries.php added] by [http://www.dankarran.com Dan Karran]).
== References ==
=== Normative References ===
* [[hcard|hCard]]
=== Informative References ===
* [http://www.ietf.org/rfc/rfc2426.txt vCard RFC2426] ([http://www.w3.org/2002/12/cal/rfc2426 HTML reformatted version of RFC2426])
* [http://www.w3.org/TR/2002/REC-xhtml1-20020801/ XHTML 1.0 SE]
* [http://www.census.gov/geo/www/tiger/tigermap.html TIGER Map Service]
* [http://en.wikipedia.org/wiki/Geotagging Wikipedia article on GeoTagging]
* [http://www.bilgipara.com Map Service]
== Work in progress ==
This specification is a work in progress. As additional aspects are discussed, understood, and written, they will be added.
* Proposals for changes, additions and other thoughts about [[geo]] may be found at [[geo-brainstorming]].
== Related Work ==
* [[luna]] (proposal for geo-style microformat for co-ordinates on The Moon)
* [[mars]] (proposal for geo-style microformat for co-ordinates on the planet Mars)
* [[geo-extension-strawman]] - extends [[geo]] to include the above, and for representing coordinates on other planets, moons etc.
* [[thoughts-on-extending-the-geo-microformat|thoughts on addind time and reference system]] to the geo microformat, that could also be used for places on other celestial bodies
== Similar Work ==
* [[adr]]
* [[hcalendar|hCalendar]]
* [[XOXO]]
== See Also ==
* [http://en.wikipedia.org/wiki/Geo_%28microformat%29 Geo on Wikipedia]
* See [http://www.technorati.com/cosmos/referer.html blogs discussing this page]
* [http://wikitravel.org/en/Wikitravel:Geocoding#Sources_for_lat.2Flongs Sources for latitude/ longitude coordinates]
== Related Pages ==

Revision as of 23:23, 21 November 2007