<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><BR><DIV><DIV>On Oct 21, 2007, at 11:51 , Lorenzo Becchi wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Hi All,</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">first of all I should apologize for my poor knowledge of OGC standards.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">To be honest, I'm not sure that what I'm writing make totally sense. But hope it does.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">In a recent debate bewteen OpenLayers (OL) and GeoNetwork (GN) communities we have tried to face a practical scenario using OGC standards.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Playing with OL and GN, I've decided to create a CSW search interface for OL to retrieve WMS or other kind of layers from a GN Catalogue.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">That's all Javascript from OL client side while it's all XML what I'm expecting from GN Catalogue (JSON output would be a dream).</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">So I can receive a list of layers, with different flavored XML, and even a OWS Context.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">I've never seen the OWS Context draft before Cameron Shorter's post sent yesterday...</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">now I'm surprised to see "FeatureType" or "Coverage" inside the ResourceList, but it seems a good way to offer a better service.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">A possible problem of OGC standards is that they relate normally to OGC standards. That's ok to me, I'm getting older.<SPAN class="Apple-converted-space"> </SPAN>But think about what Chris Schmidt (OL Core Developer) always says about standards: "I don't need standards". That's because he's always a step forward in the future.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Jeroen Ticheler's idea, he's GN director,<SPAN class="Apple-converted-space"> </SPAN>was to include mime-types in the type definition of a layer or its server,</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">ex:</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><URI mimetype="application/vnd.ogc.wms" title="National boundaries of Africa" name="national_boundaries_africa"><A href="http://geonetwork3.fao.org/ows/1">http://geonetwork3.fao.org/ows/1</A></URI></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">let's try to be creative:</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><URI mimetype="application/google.satellite" title="Google Satellite Images from Google Maps" name="satellite"><A href="http://maps.google.com/api/">http://maps.google.com/api/</A></URI></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">some more creativity:</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><URI mimetype="application/osm.streets" title="Open Street Maps - Streets" name="street"><A href="http://www.osm.org/api/5.0/">http://www.osm.org/api/5.0/</A></URI></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV>If you're thinking about WMS layers, there's the WMS Context, which is different from the OWS Context. Community MapBuilder uses WMS Context in a fairly interesting way.</DIV><DIV><BR><BLOCKQUOTE type="cite"><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">we could use this solution instead of FeatureType and Coverage or joint with them.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Adopting mime type, the client application will be able to decide to use or not a kind of service (layer) if it has an interface to support it. Otherwise it will be able to throw it away or return an exception.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Every client will be free to support standards layers but add as many new features as Chris Schmidt can invent in one month (means many).</DIV></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV>The problem with MIME types is that there's a bit of a lag in getting them defined and widely known. Furthermore, there's probably a bit of a specificity vs. generality tradeoff that has to be dealt with. Once you move away from the image types supported by WMS to vector types supported by OL, you can easily get hung up on whether you want to have named types for classes of things like Shapefiles, GeoJSON, etc, or whether you want to have named types for "Fred's GML profile for rollerblading trails". GML, in particular can lead you to an issue of typing, because "Pure GML" is not really what things get expressed in. GML data should always be expressed in an application schema, and if anyone ever figures out how to make those easy to define, they will proliferate like crazy.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><BLOCKQUOTE type="cite"><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Ex: OpenLayers and Mapbuilder can easily support GoogleMaps today, why we should avoid uDIG to support it tomorrow? Maybe Google has a clear answer about it... Anyway, same thing about OSM but OSM has already a public API; why should we not make it an OGC indexable resource?</DIV></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV>Google's answer is KML. KML could probably form the basis for a general context document. Maybe not totally general, but pretty general.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>Allan</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV> <SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><DIV style=""><FONT class="Apple-style-span" face="Courier"><SPAN class="Apple-style-span" style="font-family: Courier; "><SPAN class="Apple-style-span" style="font-family: Courier; ">-- </SPAN></SPAN></FONT></DIV><DIV style=""><FONT class="Apple-style-span" face="Courier"><SPAN class="Apple-style-span" style="font-family: Courier; "><SPAN class="Apple-style-span" style="font-family: Courier; ">Allan Doyle</SPAN></SPAN></FONT></DIV><DIV style=""><FONT class="Apple-style-span" face="Courier"><SPAN class="Apple-style-span" style="font-family: Courier; "><SPAN class="Apple-style-span" style="font-family: Courier; ">Director of Technology</SPAN></SPAN></FONT></DIV><DIV style=""><FONT class="Apple-style-span" face="Courier"><SPAN class="Apple-style-span" style="font-family: Courier; "><SPAN class="Apple-style-span" style="font-family: Courier; ">MIT Museum</SPAN></SPAN></FONT></DIV><DIV style=""><FONT class="Apple-style-span" face="Courier"><SPAN class="Apple-style-span" style="font-family: Courier; "><SPAN class="Apple-style-span" style="font-family: Courier; ">+1.617.452.2111</SPAN></SPAN></FONT></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><BR class="khtml-block-placeholder"></DIV><BR class="Apple-interchange-newline"></SPAN></SPAN> </DIV><BR></BODY></HTML>