OSGeo - User contributions [en]

User:Anneb

2011-12-05T09:32:46Z

Wiki-Anneb: Created page with "Anne Blankert GIS Software Engineer, [http://www.geodan.nl Geodan] Research * [http://mapquery.org MapQuery] * [http://www.edugis.nl EduGIS]"

Anne Blankert

GIS Software Engineer, [http://www.geodan.nl Geodan] Research

* [http://mapquery.org MapQuery]
* [http://www.edugis.nl EduGIS]

Nederlands

2011-12-05T09:27:45Z

Wiki-Anneb: /* Nederlandstalige OSGeo leden */

= Nederlandstalig OSGeo chapter =

Dit is de startpagina van OSGeoNL, het Dutch (Nederlandstalig) OSGeo Chapter. Lees hieronder over onze doelstellingen en aktiviteiten en meer.

= Historie =
Het Dutch (Nederlandstalig) OSGeo Chapter bestaat sinds 2007.
Tijdens de FOSS4G 2011 conferentie in Denver is het idee ontstaan om het Dutch local chapter nieuw leven in te blazen. Een local chapter kan worden opgezet in de vorm van een vereniging maar het kan ook een meer informeel karakter hebben waarin een groep vrijwilligers activiteiten organiseren. Op het [http://www.geo-info.nl/gin-congres GIN-congres] op 1 december 2011 is een 'birds-of-a-feather' ([http://en.wikipedia.org/wiki/Birds_of_a_feather_%28computing%29 BoF]) gehouden om te kijken wat de behoefte was onder de GIS-gebruikers en -ontwikkelaars in Nederland en welke activiteiten we als local chapter kunnen opstarten. O.a. het organiseren van "focal event" zoals een seminar op korte termijn werd door de meerderheid ondersteund. Zie ook het [[Nederland/bijeenkomsten/bof1 | verslag van de BoF]].

= Agenda =

Hieronder de agenda met diverse interne en externe events. Heb je een item van belang voeg deze dan hieronder toe.
Verslagen van sommige bijeenkomsten staan onder [[Nederland/bijeenkomsten | Bijeenkomsten]].

* Geo Freedom Day 2011, Zaterdag 10 december 2011, Het Brandpunt te Baarn [http://www.geofreedomday.nl/2011/index.html link]

= Bijeenkomsten =

Hieronder verslagen van verschillende bijeenkomsten.

* [[Nederland/bijeenkomsten | Bijeenkomsten]]

= Lid Worden =
Lid worden van OSGeoNL is heel laagdrempelig (en nog eens gratis ook). Je kunt vervolgens zelf bepalen hoe aktief je wilt worden.

De volgende 2 stappen zijn nodig:

* Word OSGeo lid door een [http://wiki.osgeo.org/index.php?title=Special:Userlogin&type=signup&returnto=Main_Page wiki-account] aan te maken
* Voeg je naam toe aan het overzicht van [[#Nederlandstalige_OSGeo_leden |Nederlandstalige OSGeo leden]].

Wil je deelnemen in de discussies? Kijk bij de [[#Mailinglijst | Mailinglijst]] en voeg jezelf toe.

= Communicatie =
Voorlopig is deze Wiki de springplank naar verdere communicatie vormen. De Wiki ben je zelf ook dus uitbreiden/aanvullen mag.

Op dit moment hebben we naast de Wiki de volgende kanalen:

* de [[#Mailinglijst | Mailinglijst]]
* Twitter: de "hashtag" [http://twitter.com/#!/search/%23osgeonl #osgeonl]
* IRC chat: Freenode kanaal #osgeonl, je kunt vanuit de browser deelnemen via [http://webchat.freenode.net/?randomnick=1&channels=osgeonl WebChat]

=Doelstelling=
Het doel van het Nederlandstalig OSGeo chapter is om het gebruik van open source GIS-software en open geodata in het Nederlandse taalgebied te stimuleren en te promoten. Bijzondere aandacht daarbij is gebruik van software uit de OSGeo-projecten.

Dit doen we door:
* het promoten van OSGeo tijdens evenementen, symposia, enzovoorts.
* het creëren van mogelijkheden voor de leden om te netwerken en informatie uit te wisselen.
* het stimuleren van het gebruik van open source GIS software aan universiteiten, hogescholen en andere onderwijsinstellingen.
* het stimuleren van het gebruik van open source GIS software bij overheidsinstellingen.
* het ondersteunen van open standaarden en de toegang tot open data in Nederland en nederlandstalige landen en gebieden.
* het vergroten van de toegankelijkheid door het ondersteunen en uitvoeren van de vertaling van belangrijke OSGeo onderdelen.

=Aanpak=
Het werven van leden en het inventariseren van de behoefte van (aspirant) leden heeft de hoogste prioriteit. 
Hoe pakken we dit aan? 
* Maak gebruik van de wiki en de mailinglijst: zorg ervoor dat de wiki up-to-date is en dat er regelmatig nieuwsberichten worden verspreid via de mailinglijst.
* Probeer via het netwerk van de reeds bestaande leden en sociale media als Twitter en LinkedIn geïnteresseerden te bereiken.
* Geef een presentatie en verspreid promotiemateriaal tijdens evenementen, zoals het [http://www.geo-info.nl/gin-congres GIN-congres], het Open Innovatie Festival (28 nov. t/m 2 dec. 2011) of [http://www.hackdeoverheid.nl Hack de Overheid]
* Zoek de samenwerking met organisaties en platformen als [http://www.noiv.nl Nederland Open in Verbinding (NOiV)]
 
Bij voldoende belangstellingen organiseren we in 2012 een OSGeo bijeenkomst met presentaties, workshops en een borrel. 

=Middelen=
We hebben promotiemateriaal nodig, bijvoorbeeld:
* leaflet,
* kaartjes,
* t-shirts.

= Mailinglijst =
Discussies vinden plaats via de Nederlandse mailinglijst van OSGeo. Je kunt je aanmelden voor deze lijst via http://lists.osgeo.org/mailman/listinfo/dutch.
Je kunt ook het [http://lists.osgeo.org/pipermail/dutch/ archief] bekijken. Is een mailinglijst nieuw voor jou?
Dan hebben we wat handige [[Nederland/mailinglijst_tips| tips]] voor je op een rijtje gezet.

= Nederlandstalige OSGeo leden =

Je wordt al lid door hieronder je naam toe te voegen plus eventueel de rol die je hebt.

* [[User:anneb | Anne Blankert]]
* [[Barend_Gehrels | Barend Gehrels]]
* [[User:Kobben | Barend Köbben]]
* [[User:bartvde | Bart van den Eijnden]]
* [[User:CoenNengerman | Coen Nengerman]]
* [[User:dirkf | Dirk Frigne]]
* [[Edward_Mac_Gillavry | Edward Mac Gillavry ]]
* [[User:Taatuut | Emil Zegers]]
* [[User:Dullaartegc| Eric Dullaart]]
* [[User:Fsteggink | Frank Steggink]]
* [[User:heikki| Heikki Doeleman]]
* [[User:ticheler | Jeroen Ticheler]]
* [[User:joachimvda | Joachim Van der Auwera]]
* [[User:Jonas | Jonas van Schrojenstein Lantman]]
* [[Joris van der Horst]]
* [[User:Just | Just van den Broecke]] - Kwartiermaker en primair contact
* [[User:Marco Duiker | Marco Duiker]]
* [[User:marten | Marten Hogeweg]]
* [[user:mprins | Mark Prins]]
* [[User:milovanderlinden | Milo van der Linden]]
* [[User:Nielshoffmann | Niels Hoffmann]]
* [[User:pauldendulk | Paul den Dulk]]
* [[User:pmeems | Paul Meems]]
* [[User:genuchten | Paul van Genuchten]]
* [[Raymond_Nijssen| Raymond Nijssen]]
* [[User:Rr.debruin| Richard de Bruin]]
* [[Richard_Duivenvoorde| Richard Duivenvoorde]]
* [[Ron Wardenier| Ron Wardenier]]
* [[User:roybraam| Roy Braam]]
* [[User:Stvn | Steven Ottens]]
* [[Thijs van Menen]]
* [[User:TjibbeChris | Tjibbe Chris Kuipers]]
* [[User:Friesewoudloper| Willy Bakker]]
* [[User:WimDeHaas | Wim de Haas]]

= Naamgeving en logo =
De voorlopige naam van het local chapter is '''OSGeo.NL'''. 
Het logo is ontworpen door [[User:Stvn | Steven Ottens]]. 
[[File:osgeonl_logo4.png]]

= Links =
Open source geo-software: 
* Map Servers (WMS/WFS/tiling)
** [http://www.geoserver.org GeoServer]
** [http://www.mapnik.org Mapnik]
** [http://www.mapserver.org MapServer]
** [http://www.deegree.org deegree]
** [http://geowebcache.org GeoWebCache] GeoWebCache tiling server
** [http://mapproxy.org MapProxy] MapProxy

* Metadata
** [http://www.geonetwork-opensource.org GeoNetwork opensource] geospatial metadata catalog
** [http://esriurl.com/geoportalserver Geoportal Server]

* Desktop GIS
** [http://www.mapwindow.org/ MapWindow]
** [http://www.qgis.org/ Quantum GIS Project]
** [http://udig.refractions.net User-friendly Desktop Internet GIS]
** [http://www.gvsig.org gvSIG]

* Geodatabase
** [http://postgis.refractions.net PostGIS]

* Web Map Viewers
** [http://www.openlayers.org OpenLayers]
** [http://www.flamingo-mc.org Flamingo MC (NL)]
** [http://heron-mc.org Heron MC (NL)]
** [https://forge.osor.eu/projects/geozet/ GEOZET], [https://github.com/geozet sourcecode]
** [http://help.arcgis.com/en/webapps/flexviewer/ ArcGIS Viewer for Flex], [https://github.com/ArcGIS/ArcGISViewerForFlex sourcecode]

* GIS framework
** [http://geomajas.org/ Geomajas] (web map viewer, transformatie, aggregatie, veiligheid)
** [http://geotools.org/ Geotools] Java framework

* Live DVD met OSGeo software
** [http://live.osgeo.org/en/index.html OSGeo Live - Bootable DVD, USB stick of virtuele machine met OSGeo software]

* INSPIRE
** [http://inspire-foss.org FOSS Componenten voor INSPIRE]

* Diversen
** [http://www.opensourcegis.nl www.opensourcegis.nl]

 
Open standaarden: 
* [http://www.geonovum.nl Geonovum]
* [http://www.noiv.nl Nederland Open in Verbinding (NOiV)]
 
Open data: 
* [http://www.openstreetmap.nl OpenStreetMap Nederland]
* [http://www.hackdeoverheid.nl Hack de Overheid]
* [http://data.overheid.nl/ Open data Overheid.nl]
* [http://www.nationaalgeoregister.nl Nationaal Georegister]
* [http://www.provinciaalgeoregister.nl Provinciaal Georegister]
* [http://geoportaal.drenthe.nl Geoportaal Drenthe]
 
Onderzoek & Onderwijs: 
* [http://www.geoictopleidingen.nl Geo-ICT Opleidingen]
* [http://elogeo.nottingham.ac.uk ELOGeo project University of Nottingham]

= Commerciële ondersteuning =

Mocht je behoefte hebben aan ondersteuning op het gebied van open source GIS, dan kun je contact opnemen met een van onderstaande bedrijven of personen. Ben je zelf een professional? Dan kun je je altijd aanmelden en je naam toevoegen aan deze lijst!

* [http://www.topx-geo-ict.nl/ TopX Geo-ICT] (was voorheen Bontepaarden) we richten ons vrnl. op MapWindow maar andere (Open-Source) GIS vraagstukken zijn ook welkom
* [http://geo.Nieuwland.nl/ Nieuwland Geoinformatie] voor geo-data hosting, ETL, applicatie bouw
* [http://www.opengeogroep.nl OpenGeoGroep] is een coöperatie van:
** [http://www.aris.nl ARIS]
** [http://www.b3partners.nl B3Partners]
** [http://www.brentjensgeoict.nl/ Brentjens Geo-ICT]
** [http://www.dogodigi.net/ Dogodigi]
** [http://www.fast-fox.nl/ FastFox ICT Solutions]
** [http://www.gisarts.nl/ GISArts]
** [http://geocat.net GeoCat] voor GeoNetwork, OpenGeo Suite en GeoCat Bridge
** [http://www.geoforza.nl/ Geoforza]
** [http://www.geoinfobalans.nl/ GeoInfoBalans]
** [http://www.justobjects.nl Just Objects] voor Heron MC, INSPIRE FOSS, GeoServer, Tiling, PostGIS, GeoTracing
** [http://www.md-kwadraat.nl/ MD-Kwadraat]
** [http://www.terglobo.nl/ Terglobo]
** [http://www.webmapper.net Webmapper] voor Quantum GIS, OpenLayers, GeoServer, MapServer, Mapnik en PostGIS
*[http://www.osgis.nl OSGIS] voor OpenLayers, GXP, GeoExt
*[http://www.geosparc.be/ Geosparc] voor Geomajas, GeoTools en PostGIS

[[Category:Local Chapters]] [[Category:Nederland]] [[Category:European Network]]

FOSS4G 2010 Code Sprint

2010-09-01T12:00:44Z

Wiki-Anneb: /* GeoJQuery */

[[Category:FOSS4G2010]] [[Category:FOSS4G]] [[Category:Code Sprints]]
== Organizing Contacts ==

*Wladimir Szczerban, Enric Rodellas

== Code Sprint - what's that? ==

A code sprint is usually organized by a group that is using an open source project and wants to see something done. They fly the developers to a single location and feed them for a couple of days with the necessities of the hacking life (internet, caffeine, electricity). The communication that happens from face to face hacking usually lasts the project for a year or more. You see this a lot in projects like Drupal etc...

== Venue ==

For map and more details see

*Date: '''Friday, 10 Sep 2010''' (the day after the conference).
*Time: '''9am-5pm'''  ([http://www.timeanddate.com/worldclock/meetingdetails.html?year=2010&month=9&day=10&hour=7&min=0&sec=0&p1=31 timeandate]) 
*'''Where:''' Citilab-Cornellà
Citilab-Cornellà
Phone: +34 93 551 06 60
Fax: +34 93 551 06 78
[http://en.citilab.eu/home/ web Citilab]
Pl. Can Suris s/n
08940 Cornellà de Llobregat (Barcelona)
*'''Rooms:''' A+B+C
*'''[http://www.openstreetmap.org/?mlat=41.359847&mlon=2.061653&zoom=18&layers=B000FTF online maps]'''

More than 100 attendees are expected!

== Motivation and Direction ==

A day, a code base, and your imagination?

Projects can use the time and venue for organizational discussions, development roadmaps, and group resolution of thorny issues in their code bases.

Is this your First Sprint? Here is some background information to get you started:

*http://www.infrae.com/about/activities/sprintathon/tips
*http://www.onlamp.com/pub/a/python/2006/10/19/running-a-sprint.html
*Example Sprint (from same people who do GeoServer): http://www.openplans.org/projects/bbq-sprint

Visit FOSS4G past experiences: [http://wiki.osgeo.org/wiki/FOSS4G_2009_Code_Sprint 2009], [http://wiki.osgeo.org/wiki/FOSS4G2008_CodeSprint 2008], [http://wiki.osgeo.org/wiki/FOSS4G2007_CodeSprint 2007 ]

== Additional Interested People ==

The following people are potentially interested in participating in sprinting activities though have not yet established a Workgroup.

* Frank Warmerdam: GDAL, MapServer, PROJ.4, OSGeo4W
* Mike Smith: GDAL, MapServer, PROJ.4, OSGeo4W
* Ari Jolma: GDAL
* Chaitanya kumar CH: GDAL
* Andrea Aime: GeoServer, GeoTools

= Workgroups =

To participate, copy a project skeleton and start a section below for your project.

== OpenLayers ==

'''Attending:'''

* [[User:Tschaub | Tim Schaub]]
* Christopher Schmidt
* Eric Lemoine
* Xurxo Méndez

'''Goals:'''

* Make OpenLayers 2.x awesomer.
* Make OpenLayers 3.0 a reality (or closer to it).

== 52°North WPS ==

'''Coordinator:'''

*Bastian Schäffer

'''Attending:'''

*Person 1

'''Goals:'''

* Technical disucssions about 52°North WPS

== Geomajas Code Sprint ==

'''Coordinator:'''

*Pieter De Graef

'''Attending:'''

*Pieter De Graef
*Jan De Moerloose
*Joachim van der Auwera
*Dirk Frigne
*Frank Maes
*Oliver May

'''Goals:'''

* Improving getting started documentation
* Create a GeoJson service, so that an OpenLayers client can make use of a Geomajas server.
* Create a Geomajas DataStore for GeoTools.
* Work toward plug-in graduation (documentation + tests)

== PostGIS ==

'''Attending:'''

* Paul Ramsey
* Olivier Courtin
* Mark Cave-Ayland
* Pierre Racine
* Vincent Picavet

'''Goals:'''

* Synchronize fall development goals
* Discuss ISO type extensions
* Discuss official raster integration issues
* Discuss OGR based SQL loader
* Discuss build simplification

== GeoJQuery ==

'''Coordinator:'''

* [[User:Vmische | Volker Mische]]

'''Attending:'''

* [[User:Astrid Emde | Astrid Emde]]
* [[User:Testbaudson | Christoph Baudson]]
* [[User:Jacarma | Javi Carrasco]]
* [[Arnulf Christl]]
* Anne Blankert

'''Goals:'''

* getting started
* ...

== gvSIG ==

Someone asked at gvSIG mailing lists ([http://listserv.gva.es/pipermail/gvsig_desarrolladores/2010-August/004697.html 1], [http://listserv.gva.es/pipermail/gvsig_internacional/2010-August/005857.html 2]) about a possible gvSIG code sprint at Barcelona FOSS4G.

'''(Tentative) coordinator:'''

* [[Jorge Sanz]]

'''Attending:'''

* [[User:Amaneiro | Andrés Maneiro]]
* [[User:nachouve | Nacho Varela]]
* [[User:jpiera | Jorge Piera]]

'''Goals:'''

* Disscuss about how is possible to migrate NavTable to gvSIG 2.0.
* Talk about usability
** TOC
** Labelling and Symbology
** Project Preferences

== LiveDVD ==

Interested in localization of the LiveDVD as asked on the mailing list? http://lists.osgeo.org/pipermail/live-demo/2010-August/002518.html

'''Attending:'''

* [[User:Danielkastl | Daniel Kastl]]
* [[User:Astrid Emde | Astrid Emde]]
* [[User:Stephan Holl | Stephan Holl]]

'''Goals:'''

* Discuss localization
* getting started
* translate the documentation to german ;) to get the OSGeoLiveDVD ready for Intergeo in october 2010
* ...

== MapServer ==

'''Attending:'''

* [[User:Dmorissette | Daniel Morissette]]
* [[User:msmitherdc | Michael Smith ]]
* Steve Lime (via IRC)
* [[User:Schpidi | Stephan Meissl]]
* [[User:jmckenna | Jeff McKenna]]
* [[User:aboudreault | Alan Boudreault (via IRC)]]
* [[User:tbonfort | Thomas Bonfort]]
* ...

'''Goals:'''

* Discuss 6.0 release plans (if enough members of the PSC/Devs are present)
* ...

== Mapnik ==

The Mapnik project is planning a code sprint in London in late september.

Therefore, no current plans for sprinting post foss4g (Dane in particular is going to the beach).

But, get in touch with Dane if you are interested in meeting up during foss4g ([[User:Springmeyer]])

Talk:Tile Map Service Specification

2010-03-08T10:04:26Z

Wiki-Anneb: /* Things To Discuss */

===Things To Discuss===

* Shouldn't this wiki page describe exactly how to get to the metadata of a given TMS?
The examples currently describe:

'''Root Resource'''
<pre>http://tms.osgeo.org/</pre>
should we assume we got this URL from some other source, possibly a CSW? Could the Url just as well be something like <pre>"http://mytms.mydomain.tld/myservices/mytms/</pre> ?

Then
<pre>http://www.osgeo.org/services/root.xml</pre>
Where does the "/services/root.xml" part come from? Just append it to the root resource? If known, please describe.

Then the <TileMapService> resource:
<pre>http://tms.osgeo.org/1.0.0/</pre>
Where does this come from? Did we get this URL from the response to the Root Resource URL above?

Then
<pre>http://www.osgeo.org/services/tilemapservice.xml</pre>
Where does the "/services/tilemapservice.xml" part come from? Just append it to the root resource? If known, please describe.

Same questions for
<pre>/vmap0</pre>, <pre>/1.0.0/landsat2000</pre>, <pre>/basemap.xml</pre> ?

Wouldn't it be nice if this Wiki page would use an internally consistent set of TMS metadata? If not, why bother storing metadata with the TMS at all? Please delete and forgive my ignorance if this comment should completely miss the point of this Wiki page.

* This specification is RESTful, but OGC specifications are not. Do we care?
** We could ask OGC. There is a meeting in December, maybe some OSGeo folk is there to ask it ([[User:Arnulf Christl | Arnulf] is there).
* How much of the WMS capabilities metadata do we want to replicate? Some looks interesting, some not.
* Does the pre-amble need to be fluffed up a bit with some pictures and diagrams to explain some tiling basics to those not already acquainted (probably).
* On IRC, mloskot worries that the XML resources might be overly verbose for what they are transmitting. pramsey wonders if, since we have gone this far from the OGC mothership, jettisoning XML altogether for something like json might not be better. ianturton thinks that xml is easier to work with but maybe we can support both?
* The use of various elements needs description, in particular the <Origin> and <BoundingBox> which appear redundant. IanT changed the Origin of one of the examples to (-180,-90) from (-180,-180). The original origin (which makes no sense in lat/lon as spherical coords, but is acceptable if you are pretending they are cartesian, as mapping apps do) was placed there to allow for 2x2 256x256 tiles to fit into the plane at the top zoom level. Another equally acceptable layout though, is to have IanT's origin and use 2x1 256x256 tiles. I cannot recall why the BoF didn't like that as much as having a square initial extent.
* I can sort of see the basis for this, but it looks like I have to download twice as many tiles as I need when I veiw the whole world which is likely to be the most common view requested. IanT
* Only at very zoomed out views, so it's not that big an imposition. At zoomed in views, presumably you are more interested in looking at actual data than the blank spaces between the Origin and the BoundingBox. PaulR
* What about 304 (unmodified) should be documented? the whole request/response thing is a little complex, and it's not an errorcode per se... PaulR
* (user mmanzato) Several applications I am currently considering focus on a regional or urban context outside of which there is no cartographic coverage. Here UTM projection (or other local projections) are much more useful/meaningful than global-geodetic or global-mercator.
** I understand that the "local" profile is there exactly for this purpose. Correct?
** Bulletpoint 2 in local profile definition should read: "Must provide <TileSet>s with units-per-pixel meeting the following formula: units-per-pixel = 2^n, for '''some''' integral value of n greater than or equal to 0" (it is not necessary to provide all resolutions!)
** Given what third bulletpoint says I would expect that tiles with units-per-pixel=2^n are in <ProfileUrl>/n, so:
<pre><code>
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/11" units-per-pixel="2048" order="0" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/10" units-per-pixel="1024" order="1" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/9" units-per-pixel="512" order="2" />
...
</code></pre>

Tile Map Service Specification

2010-03-08T09:34:40Z

Wiki-Anneb: /* Document Scope */

This document is the work of a loose community of participants interested in client/server mapping solutions that use multi-resolution image pyramids. It is meant to be used as a baseline for the implementation of client/server mapping software. It is not an "official standard" nor is it endorsed by OSGeo as an official project or work product of the Foundation.

This document is version "1.0", and will not be edited further.

Any new revisions will take place in a new working copy.

==Introduction==

===Document Scope===

A Tile Map Service (TMS) provides access to cartographic maps of geo-referenced data, not direct access to the data itself. This document standardizes the way in which map tiles are requested by clients, and the ways that servers describe their holdings.

===Document Form===

This document will proceed from a description of general resources provided by the server to particular resources (such as map tiles) providing examples of access URLs and return values at each stage.

==Specification==

The Tiled Web Service provides access to resources, in particular, to rendered cartographic tiles at fixed scales. Access to these resources is provided via a "REST" interface, starting with a root resource describing available layers, then map resources with a set of scales, then scales holding sets of tiles.

Each resource contains the descriptive information and links to further resources. Note that while the URLs used to access resources may appear to have internal meaning (the resource for version 1.0.0 of the service has "1.0.0" in it's URL) such structure is ''not required'' of them.

The only requirement is that the resource be referenced by a URL (<nowiki>http://tms.osgeo.org/1.0.0/ could be http://tms.osgeo.org/onepointzeropointzero or http://tms.osgeo.org/flipper.xml as long as the value appeared in the href of the <TileMapService> element</nowiki>).

The value of an "href" '''must''' be an absolute URL (starting with "http://"). For example: href="<nowiki>http://www.service.org/subdirectory/tilemap.xml</nowiki>"

===Root Resource===

The root resource describes the available versions of the <TileMapService> (and possibly other services as well).

Request:

<nowiki>http://tms.osgeo.org/</nowiki>

Response (Content-type: text/xml):

<nowiki><?xml version="1.0" encoding="UTF-8" ?>
<Services>
<TileMapService title="Example Tile Map Service" version="1.0.0" href="http://tms.osgeo.org/1.0.0/" />
<TileMapService title="New Example Tile Map Service" version="1.1.0" href="http://tms.osgeo.org/1.1.0/" />
<FancyFeatureService title="Features!" version="0.9" href="http://ffs.osgeo.org/0.9/" />
</Services></nowiki>

Request:

<nowiki>http://www.osgeo.org/services/root.xml</nowiki>

Response:

<nowiki><?xml version="1.0" ?>
<Services>
<TileMapService title="Example Static Tile Map Service" version="1.0.0" href="http://www.osgeo.org/services/tilemapservice.xml" />
</Services></nowiki>

===TileMapService Resource===

The <TileMapService> resource provides description metadata about the service and lists the available <TileMaps>.

Optional elements in the resource are called out below using the pipe character. All other elements are mandatory.

Request:

<nowiki>http://tms.osgeo.org/1.0.0/</nowiki>

Response (Content-type: text/xml):

<nowiki><?xml version="1.0" encoding="UTF-8" ?>
<TileMapService version="1.0.0" services="http://tms.osgeo.org">
<Title>Example Tile Map Service</Title>
<Abstract>This is a longer description of the example tiling map service.</Abstract>
| <KeywordList>example tile service</KeywordList>
| <ContactInformation>
| <ContactPersonPrimary>
| <ContactPerson>Paul Ramsey</ContactPerson>
| <ContactOrganization>Refractions Research</ContactOrganization>
| </ContactPersonPrimary>
| <ContactPosition>Manager</ContactPosition>
| <ContactAddress>
| <AddressType>postal</AddressType>
| <Address>300 - 1207 Douglas Street</Address>
| <City>Victoria</City>
| <StateOrProvince>British Columbia</StateOrProvince>
| <PostCode>V8W2E7</PostCode>
| <Country>Canada</Country>
| </ContactAddress>
| <ContactVoiceTelephone>12503833022</ContactVoiceTelephone>
| <ContactFacsimileTelephone>12503832140</ContactFacsimileTelephone>
| <ContactElectronicMailAddress>pramsey@refractions.net</ContactElectronicMailAddress>
| </ContactInformation>
<TileMaps>
<TileMap
title="VMAP0 World Map"
srs="EPSG:4326"
profile="global-geodetic"
href="http://tms.osgeo.org/1.0.0/vmap0" />
<TileMap
title="British Columbia Landsat Imagery (2000)"
srs="EPSG:3005"
profile="local"
href="http://tms.osgeo.org/1.0.0/landsat2000" />
</TileMaps>
</TileMapService></nowiki>

Request:

<nowiki>http://www.osgeo.org/services/tilemapservice.xml</nowiki>

Response (Content-type: text/xml):

<nowiki><?xml version="1.0" encoding="UTF-8" ?>
<TileMapService version="1.0.0" services="http://www.osgeo.org/services/root.xml">
<Title>Example Static Tile Map Service</Title>
<Abstract>This is a longer description of the static tiling map service.</Abstract>
| <KeywordList>example tile service static</KeywordList>
| <ContactInformation>
| <ContactPersonPrimary>
| <ContactPerson>Paul Ramsey</ContactPerson>
| <ContactOrganization>Refractions Research</ContactOrganization>
| </ContactPersonPrimary>
| <ContactPosition>Manager</ContactPosition>
| <ContactAddress>
| <AddressType>postal</AddressType>
| <Address>300 - 1207 Douglas Street</Address>
| <City>Victoria</City>
| <StateOrProvince>British Columbia</StateOrProvince>
| <PostCode>V8W2E7</PostCode>
| <Country>Canada</Country>
| </ContactAddress>
| <ContactVoiceTelephone>12503833022</ContactVoiceTelephone>
| <ContactFacsimileTelephone>12503832140</ContactFacsimileTelephone>
| <ContactElectronicMailAddress>pramsey@refractions.net</ContactElectronicMailAddress>
| </ContactInformation>
<TileMaps>
<TileMap
title="Vancouver Island Base Map"
srs="EPSG:26910"
profile="none"
href="http://www.osgeo.org/services/basemap.xml" />
</TileMaps>
</TileMapService></nowiki>

===TileMap Resource===

A <TileMap> is a (usually) cartographically complete map representation. Sometimes <TileMap>s are built to be used in conjunction, as a set of stacked layers, but they are generally visually complete on their own.

<TileMap>s are composed of a set of scale-appropriate cartographic renderings, each divided up into regularly spaced image tiles, called <TileSet>s. Small-scale (eg, 1:10000000) tile sets may only contain a handful of tiles. Large-scale tile sets (eg, 1:10000) may contain millions of tiles.

At a particular scale, and in a particular cartographic projection, a <TileMap> is represented by a <TileSet>, a coverage of regularly sized and spaced images that taken together form a complete visual representation of the entire area of coverage of the <TileMap>.

Request:

<nowiki>http://tms.osgeo.org/1.0.0/vmap0</nowiki>

Response (Content-type: text/xml):

<nowiki><?xml version="1.0" encoding="UTF-8" ?>
<TileMap version="1.0.0" tilemapservice="http://http://tms.osgeo.org/1.0.0">
<Title>VMAP0 World Map</Title>
<Abstract>A map of the world built from the NGA VMAP0 vector data set.</Abstract>
| <KeywordList></KeywordList>
| <Metadata type="TC211" mime-type="text/xml" href="http://www.org" />
| <Attribution>
| <Title>National Geospatial Intelligence Agency</Title>
| <Logo width="10" height="10" href="http://nga.mil/logo.gif" mime-type="image/gif" />
| </Attribution>
| <WebMapContext href="http://wms.org" />
| <Face>0</Face>
<SRS>EPSG:4326</SRS>
<BoundingBox minx="-180" miny="-90" maxx="180" maxy="90" />
<Origin x="-180" y="-90" />
<TileFormat width="256" height="256" mime-type="image/jpeg" extension="jpg" />
<TileSets profile=global-geodetic">
<TileSet href="http://tms.osgeo.org/1.0.0/vmap0/0" units-per-pixel="0.703125" order="0" />
<TileSet href="http://tms.osgeo.org/1.0.0/vmap0/1" units-per-pixel="0.3515625" order="1" />
<TileSet href="http://tms.osgeo.org/1.0.0/vmap0/2" units-per-pixel="0.17578125" order="2" />
<TileSet href="http://tms.osgeo.org/1.0.0/vmap0/3" units-per-pixel="0.08789063" order="3" />
</TileSets>
</TileMap></nowiki>

Request:

<nowiki>http://tms.osgeo.org/1.0.0/landsat2000</nowiki>

Response (Content-type: text/xml):

<nowiki><?xml version="1.0" encoding="UTF-8" ?>
<TileMap version="1.0.0" tilemapservice="http://tms.osgeo.org/1.0.0">
<Title>British Columbia Landsat Imagery (2000)</Title>
<Abstract>Landsat data collected in the year 2000 over British Columbia.</Abstract>
| <KeywordList></KeywordList>
| <Metadata type="TC211" mime-type="text/xml" href="http://www.org" />
| <Attribution>
| <Title>Government of British Columbia</Title>
| <Logo width="10" height="10" href="http://gov.bc.ca/logo.png" mime-type="image/png" />
| </Attribution>
| <WebMapContext href="http://wms.gov.bc.ca" />
<SRS>EPSG:3005</SRS>
<BoundingBox minx="100000" miny="100000" maxx="1800000" maxy="1800000" />
<Origin x="100000" y="100000" />
<TileFormat width="256" height="256" mime-type="image/png" extension="png" />
<TileSets profile="local">
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/2048" units-per-pixel="2048" order="0" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/1024" units-per-pixel="1024" order="1" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/512" units-per-pixel="512" order="2" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/256" units-per-pixel="256" order="3" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/128" units-per-pixel="128" order="4" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/64" units-per-pixel="64" order="5" />
</TileSets>
</TileMap></nowiki>

Request:

<nowiki>http://www.osgeo.org/services/basemap.xml</nowiki>

Response (Content-type: text/xml):

<nowiki><?xml version="1.0" encoding="UTF-8" ?>
<TileMap version="1.0.0" tilemapservice="http://www.osgeo.org/services/tilemapservice.xml">
<Title>Vancouver Island Base Map</Title>
<Abstract>A map of the Vancouver Island built from British Columbia planimetric mapping
data and digital elevation hill shading.</Abstract>
| <KeywordList></KeywordList>
| <Metadata type="TC211" mime-type="text/xml" href="http://www.org" />
| <Attribution>
| <Title>Goverment of British Columbia</Title>
| <Logo width="10" height="10" href="http://www.gov.bc.ca/logo.gif" mime-type="image/gif" />
| </Attribution>
| <WebMapContext href="http://openmaps.gov.bc.ca" />
<SRS>EPSG:26910</SRS>
| <Face>0</Face>
<BoundingBox minx="500000" miny="4800000" maxx="700000" maxy="5500000" />
<Origin x="500000" y="4800000" />
<TileFormat width="256" height="256" mime-type="image/png" extension="png" />
<TileSets profile="none">
<TileSet href="http://www.osgeo.org/services/basemap/L1" units-per-pixel="6400" order="0" />
<TileSet href="http://www.osgeo.org/services/basemap/L2" units-per-pixel="1600" order="1" />
<TileSet href="http://www.osgeo.org/services/basemap/L3" units-per-pixel="400" order="2" />
<TileSet href="http://www.osgeo.org/services/basemap/L4" units-per-pixel="100" order="3" />
<TileSet href="http://www.osgeo.org/services/basemap/L5" units-per-pixel="25" order="4" />
</TileSets>
</TileMap></nowiki>

Each <TileMap> supports one <SRS> and one image format. To support more than one SRS or image format, define extra <TileMaps> in your <TileMapService> for each combination you want.

<TileMap>s have both a <BoundingBox> and an <Origin>. The <BoundingBox> is the extent of the data of interest -- it might be used by a client to set an initial spatial extent. The <Origin> is the lower-left corner of the 0/0 tile, and the upper right corner of tile -1/-1 (if you choose to configure your service so that negative tiles are required). The <Origin> may be outside of the visual region of interest (the <BoundingBox>), for reasons of implementation convenience.

<TileMap>s may participate as a <Face> of a larger complex of <TileMap>s. The OSGPlanet and GeoFusion clients both use separate polar faces in conjuction with equatorial faces (an "earth cube") to create a single world view from multiple tile maps. See [[#Using Faces]].

<TileMap>s may implement one of three "profile"s, two global profiles in common global projections, or a local profile in an arbitrary projection. All profiles restrict the service to a fixed set of scales, to allow tilesets from different services to be more easily overlaid.

===Profiles===

Using this server specification will ensure that clients can easily consume your tiled map data. However, it will not guarantee that clients can efficiently overlay your data with data from other tile map servers. In order to maximize the interoperability of your tile map with other tile maps, you must implement the a "profile" for your tile map.

The profile a <TileMap> supports is advertised in the "profile" attribute of the <TileSets> element. The "profile" will be one of:

* none
* global-geodetic
* global-mercator
* local

====global-geodetic====

If the profile type is set to "global-geodetic", the <TileMap> must meet the following requirements:

* Must use <SRS>EPSG:4326</SRS>
* Must provide <TileSet>s with units-per-pixel meeting the following formula for any integral value of "n" greater than or equal to 0: units-per-pixel = 0.703125 / 2^n
** This scaling allows an initial zoom level that consists of 2 256x256 pixel tiles covering the whole earth, with an <Origin> of (-180,-90). Other combinations of tile size and <Origin> are also possible at this scale.

<nowiki><TileSets profile="global-geodetic">
<TileSet href="http://tms.osgeo.org/1.0.0/vmap0/0" units-per-pixel="0.703125" order="0" />
<TileSet href="http://tms.osgeo.org/1.0.0/vmap0/1" units-per-pixel="0.3515625" order="1" />
<TileSet href="http://tms.osgeo.org/1.0.0/vmap0/2" units-per-pixel="0.17578125" order="2" />
<TileSet href="http://tms.osgeo.org/1.0.0/vmap0/3" units-per-pixel="0.08789063" order="3" />
</TileSets></nowiki>

====global-mercator====

If the profile type is set to "global-mercator", the <TileMap> must meet the following requirements:

* Must use <SRS>OSGEO:41001</SRS>
* Must provide <TileSet>s with units-per-pixel meeting the following formula for any integral value of "n" greater than or equal to 0: units-per-pixel = 78271.516 / 2^n
** This scaling allows an initial zoom level that consists of four 256x256 pixel tiles covering the whole earth, with an <Origin> of (-20037508.34, -20037508.34). Other combinations of tile size and <Origin> are also possible at this scale.

====local====

Unlike the global profiles, the "local" profile is built from the bottom up, starting with a smallest possible scale of one unit per pixel and compounding upwards from there. Local profiles can be in any projection, but are at a fixed set of scales.

If the profile type is set to "local", the <TileMap> must meet the following requirements:

* May use any coordinate system, and must identify that coordinate system in the <SRS>.
* Must provide <TileSet>s with units-per-pixel meeting the following formula for any integral value of "n" greater than or equal to 0: units-per-pixel = 2^n
* Must provide <TileSet> sub-directories below the <Profile> href value, using the value of "n" appropriate for that <TileSet> as the sub-directory name.

<nowiki><SRS>EPSG:3005</SRS>
<BoundingBox minx="100000" miny="100000" maxx="1800000" maxy="1800000" />
<Origin x="100000" y="100000" />
<TileSets profile="local">
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/6" units-per-pixel="2048" order="0" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/5" units-per-pixel="1024" order="1" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/4" units-per-pixel="512" order="2" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/3" units-per-pixel="256" order="3" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/2" units-per-pixel="128" order="4" />
<TileSet href="http://tms.osgeo.org/1.0.0/landsat2000/1" units-per-pixel="64" order="5" />
</TileSets></nowiki>

===Tile Resources===

The origin of a <TileMap> is defined in the coordinates of the spatial reference system of the <TileMap>. The x-coordinate of the tile numbers increases with the x-coordinate of the spatial reference system, and the y-coordinate of the tile numbers also increases with the y-coordinate of the spatial reference system.

Tiles are addressed under the "href" specified in the <TileSet> appending the "x" tile coordinate as a directory name and using the "y" tile coordinate as the file name, with the file "extension" from the <TileFormat>.

Example:

The tile at the origin of the tile set in the first zoom level of vmap0.
<nowiki>http://tms.osgeo.org/1.0.0/vmap0/levelzero/0/0.jpg</nowiki>

The tile near the middle of the tile set in the third zoom level of vmap0.
<nowiki>http://tms.osgeo.org/1.0.0/vmap0/leveltwo/3/4.jpg</nowiki>

The tile near the middle of the tile set in the fifth zoom level of landsat2000.
<nowiki>http://tms.osgeo.org/1.0.0/landsat2000/1/8500/8500.png</nowiki>

The tile at the origin of the tile set in the first zoom level of basemap.
<nowiki>http://www.osgeo.org/services/basemap/L1/0/0.png</nowiki>

===TileMap Diagram===

[[Image:Tms.png]]

===Error Handling===

When an error occurs in the server, it is important that the client be able easily notice that an error has occurred, and ascertain ''why'' the error occured so the user can be notified if necessary.

The tile map server uses HTTP error codes to relay the general reason for an error condition, and an XML payload to communicate the specific reason for the failure in human readable language.

Only HTTP error codes given in this specification should be used to return errors to the client.

* The client requests a nonexistent resource URL. Return HTTP error code 404 (Not Found)
* The server fails in processing a response for a valid resource URL. Return HTTP error code 500 (Internal Server Error)

Servers are optionally allowed to return content, even when throwning an error code. The following is the XML format for a tile map server error message. If the Content-type of the return on an error is set to text/xml, this format is the required form of the response.

<nowiki><?xml version="1.0" ?>
<TileMapServerError>
<Message>The requested tile is outside the bounding box of the tile map.</Message>
</TileMapServerError></nowiki>

==Implementation Advice==

===Spatial Referencing Systems===

Spatial referencing systems for the tile map service will be defined using the EPSG database as a reference for "well-known" projections, subject to interpretations, given below.

There are two substantial implementation issues with using the EPSG database as a source of truth for spatial reference systems:

* Firstly, the EPSG database has some specific definitions for commonly used geodetic coordinate systems, in particular EPSG:4326 -- geodetic coordinates relative to the WGS84 spheroid. The EPSG definition for 4326 says that the coordinate order is latitude, longitude and that the units are degrees, minutes, seconds. However, common usage of EPSG:4326 in web mapping says that the coordinate order is longitude, latitude and the units are decimal degrees.
* Secondly, the EPSG database does not include every commonly used spatial reference system. There are still many local systems which are not included in the database, though the EPSG does make an effort to include new systems as they are brought to their attention. However, the EPSG does not catalogue commonly used global and large area systems, presumably as a matter of policy. For example, no EPSG identifier is provided for a Mercator projection of the world, or an Albers projection of North America.

The issues will be dealt with by fiat in this specification, matching implementation practice rather than following the database definition:

* For all geodetic coordinate systems in the EPSG database, the tile map service specification will treat the coordinate order as longitude, latitude and the units as decimal degrees.
* Spatial reference systems not defined in the EPSG database may be defined in the tile map service specification itself, using an OSGEO authority string.
** '''OSGEO:41001''' <nowiki>PROJCS["WGS84 / Simple Mercator", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS_1984",6378137,298.257223563]], PRIMEM["Greenwich",0], UNIT["Decimal_Degree", 0.0174532925199433]], PROJECTION["Mercator_1SP"], PARAMETER["central_meridian",0], PARAMETER["false_easting",0], PARAMETER["false_northing",0], UNIT["Meter",1]]</nowiki>
** '''OSGEO:42310''' <nowiki>PROJCS["WGS84+GRS80 / Mercator", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["GRS 1980",6378137,298.257222101], TOWGS84[0,0,0]], PRIMEM["Greenwich",0], UNIT["Decimal_Degree",0.0174532925199433]], PROJECTION["Mercator_1SP"], PARAMETER["central_meridian",0], PARAMETER["false_easting",0], PARAMETER["false_northing",0], UNIT["Meter",1]]</nowiki>
** '''OSGEO:42101''' <nowiki>PROJCS["WGS 84 / LCC Canada", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS_1984",6378137,298.257223563]], PRIMEM["Greenwich",0], UNIT["Decimal_Degree",0.0174532925199433]], PROJECTION["Lambert_Conformal_Conic_2SP"], PARAMETER["central_meridian",-95.0], PARAMETER["latitude_of_origin",0], PARAMETER["standard_parallel_1",49.0], PARAMETER["standard_parallel_2",77.0], PARAMETER["false_easting",0.0], PARAMETER["false_northing",-8000000.0], UNIT["Meter",1]]</nowiki>
** '''OSGEO:42304''' <nowiki>PROJCS["NAD83 / NRCan LCC Canada", GEOGCS["NAD83", DATUM["North_American_Datum_1983", SPHEROID["GRS_1980",6378137,298.257222101], TOWGS84[0,0,0]], PRIMEM["Greenwich",0], UNIT["Decimal_Degree",0.0174532925199433]], PROJECTION["Lambert_Conformal_Conic_2SP"], PARAMETER["central_meridian",-95.0], PARAMETER["latitude_of_origin",49.0], PARAMETER["standard_parallel_1",49.0], PARAMETER["standard_parallel_2",77.0], PARAMETER["false_easting",0.0], PARAMETER["false_northing",0.0], UNIT["Meter",1]]</nowiki>

===Maximizing Cacheability===

Tile maps are usually base maps, and usually represent data that changes on a very slow cycle. They are also usually large in volume, comprising potentially millions of different tiles. Given these basic facts, the aggressive use of caching strategies can optimize performance of tile map services.

Caching can happen at multiple layers between the server and the client:

* At the client itself, as the user-agent caches results on the local disk.
* In a shared cache at an intermediate ISP, allowing multiple users of the ISP to pull data from the cache.
* In a cache on the server itself, to move load from the tile generator to a simpler caching process.

In order for caching to occur at any of these layers, the caching mechanisms need to know when a resource is cachable.

If your tile server is written using a scripting or programming language, you will probably be constructing your HTTP headers yourself, and it is important to include cache control headers when doing so to allow caching to occur.

There are different cache headers for HTTP 1.0 and HTTP 1.1, and because both protocols are in active use, it is important to include both.

For HTTP 1.0, use the "Expires" header. If you expect your data to change no more than once per week, set your Expires header to one week in the future. For example, if it is January 1, 2007, and you wanted your tiles to expire no more than one week after they are retreived, you would set your header using this PHP invocation:

header('Expires: Mon, 8 Jan 2007 14:57:12 GMT');

Or, to always set the Expires header to one week in the future:

header('Expires: ' . gmdate('D, j M Y H:i:s T', time() + 7 * 24 * 60 * 60)); // time + 7 days worth of seconds

For HTTP 1.1, use the "Cache-control" header. Unlike the older "Expires" header, "Cache-control" does not have a clock reference, just a time period to reatain the data, thereby avoiding the clock sychronization issues of "Expires".

header('Cache-Control: max-age=86400, must-revalidate');
header('Cache-Control: ' . 7 * 24 * 60 * 60 );

Read about HTTP 1.1 cache control headers in the [http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9 W3.org specification].

===Implementing Cacheability===

You can trust that the somewhere on the internet, someone will respect your cache control headers and your content will be cached, ''or'' you can set up your own cache. If you are running Apache 2.0 adding [http://httpd.apache.org/docs/2.0/mod/mod_cache.html mod_cache caching] to your tms is laughably easy.

Just add a mod_cache directive inside your <VirtualHost> definition:

<IfModule mod_disk_cache.c>
CacheRoot /tmp/apache-cache
CacheSize 1024000
CacheEnable disk /cgi-bin/tms
CacheDirLevels 5
CacheDirLength 3
</IfModule>

This example is for a disk cache, probably what you will use for your TMS, since the data volumes tend to be high. Note how the CacheEnable directive allows you to very precisely control which content you are going to cache. In my case, I am only caching the output from my TMS server, nothing else. If I wanted, I could be even narrower and restrict caching to just one tile map inside my service, or just one tile set.

===URLs That are Actually Scripts===

For large implementations of the tile map server specification, the data will not be statically pre-built, but will be demand-generated by some kind of backend service. That means that URLs that appear to be static may actually be dynamic.

The [http://hoohoo.ncsa.uiuc.edu/cgi/env.html CGI specification] allows this trivially, by passing any path information after the CGI executable in the URL back to the executable in the PATH_INFO environment variable:

<nowiki>http://tms.osgeo.org/cgi-bin/tms/1.0.0/vmap0</nowiki>

PATH_INFO = 1.0.0/vmap0

If "tms" is the CGI executable, it can easily extract the remaining path information and use that for processing purposes.

Note that by default some versions of Microsoft IIS do not conform to the CGI specification for this behavior (Apache does). See the note at http://support.microsoft.com/kb/q184320/ for information on how to enable this bahavior in IIS.

Note that it is allowable for URLs to include "."s in the middle of paths, so that executable scripts (like PHP files) can be legally used as TMS servers.

Here is a root resource:
<nowiki>http://tms.osgeo.org/tms.php</nowiki>

Here is the a tile request on that server:
<nowiki>http://tms.osgeo.org/tms.php/1.0.0/thetilemap/firstlevel/2/1.jpg</nowiki>

In general, the simplest way to extract information from the incoming script invocation is to take the incoming PATH_INFO environment variable, strip the "/" character from the start and end of the string, and then split the string into an array using the "/" character. In this manner, the first element of the array will be the version, the second element will be the tile map, the third will be the level, the fourth will be the tile "x" and the fifth will be the tile "y" (with a .extension).

===Using Faces===

The "face-id" attribute of the <TileMap> referenced in the <TileMapService> is used for some specialized clients. How that attribute is used by each client is described here.

''To be filled in by implementation knowledge...''

===Reference Implementations===

====Servers====

* TileCache
** http://www.tilecache.org/

====Clients====

* Worldkit: http://worldkit.org/tilemap/
* Openlayers: http://openlayers.org/
* Cadcorp SIS: [http://wiki.osgeo.org/images/a/a5/CadcorpTmsClient.png Screenshot]

===Returning Error Codes===

If your tile map server is a static set of files, you will find that your web server sets the appropriate error codes automatically when people ask for resources that do not exist, or the server suffers a failure.

However, if your tile map server is dynamic, you will have to set the HTTP status codes yourself, otherwise the HTTP server will assign a code of 200 (OK) for your error message XML document, which would be wrong. In PHP, an error return function might look like this:

header("HTTP/1.0 404 Not Found");
header("Content-type: text/xml");
print "<?xml version='1.0' ?>";
print "<TileMapServerErrror>";
print "<Message>You requested a map tile [ $path_info ] that does not exist.</Message>";
print "</TileMapServerError>";

Note that in addition to setting the error code the Content-type was also correctly set. Also note that cache headers were ''not'' set, since errors are not a good thing to cache.

==See Also==

* [http://www.peej.co.uk/articles/http-caching.html HTTP Caching]
* [http://www.peej.co.uk/articles/rest.html What is REST]

[[Category:Standards]]
[[Category:Tiling]]