<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">Tom, you wrote Wed, 2 Aug 2006 11:31:43 -0400:</font></font></span></p>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> I see two levels of decision here:</font></font></span></p>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> 1./ RESTful interface</font></font></span></p>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> 2./ underlying information model</font></font></span></p>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> 2./ output content model</font></font></span></p>
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<div class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'; mso-ansi-language: EN-GB; mso-bidi-font-family: 'Times New Roman'">With 'underlying information model' do you mean that information that can be taken for requests?
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<div class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> I would go with a WFS as the interface standard (flexible API).<span style="mso-spacerun: yes">
</span>In our</font></font></span></div>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> experiences with owscat, we found WFS to be flexible, and can already be
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> integrated with WFS client tools, as well as the option of going with</font>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> open source WFS servers out-of-the-box (MapServer, GeoServer, deegree).
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">Don't take me wrong WMS and WFS are good specs. But WFS make reference to Filter. And for a simple protocol I'd like to have a simple query language, mainly to boolean and perhaps wildcard matches. So IMHO WFS query should be really profiled and constrained to REST (no SOAP).
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">The fact that open source WFS exist out-of-the-box is a plus. But what about repositories in other languages like C or C# (as many commercial desktop GIS)?
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">What I have in mind is that even pure data file provides (like KML, Shape, DXF, GeoTIFF, etc.) can participate - without a database and without SQL engine.
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font face="Courier New" size="2">OAI-PMH offers a spec. and implementations - as well as services and gateways - called static repository:
</font><a href="http://www.openarchives.org/OAI/2.0/guidelines-static-repository.htm"><font face="Courier New" size="2">http://www.openarchives.org/OAI/2.0/guidelines-static-repository.htm</font></a><font size="2"><font face="Courier New">
.</font></font></span></p>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">Forgive me when I mentioned that spec. again. I think code first, think later will allow for several approaches here.
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> For an information model, I would envision a model (or db tables) like:
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> </font></font></span></p>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> service_endpoints</font></font></span></p>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> service_resources</font></font></span></p>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> data_resources</font></font></span></p>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> </font></font></span></p>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> Where service_endpoints and service_resources are basically a split of</font>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> an OGC Capabilities XML document (service vs. layer metadata) with</font>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> foreign key refs associating them.</font></font></span></p>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font face="Courier New" size="2"> </font></span></p>
<div class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'; mso-ansi-language: EN-GB; mso-bidi-font-family: 'Times New Roman'">Don't understand this yet, have to think about this again.
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font face="Courier New" size="2"> </font></span></p><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2">
<font face="Courier New">
<div class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'; mso-ansi-language: EN-GB; mso-bidi-font-family: 'Times New Roman'">Is'nt something like those 6 queries from OAI-PMH enough combined with
<font size="2"><font face="Courier New">the minimally extended Dublin Core (including coverage as <span lang="EN-GB" style="FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'; mso-ansi-language: EN-GB; mso-bidi-font-family: 'Times New Roman'">
spatial constraints (bbox)) as output content model enough whereas </span></font></font></span><span lang="EN-GB" style="FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'; mso-ansi-language: EN-GB; mso-bidi-font-family: 'Times New Roman'">
every attribute from the extended Dublin Core can be queried</span><span lang="EN-GB" style="FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'; mso-ansi-language: EN-GB; mso-bidi-font-family: 'Times New Roman'">? </span><span lang="EN-GB" style="FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'; mso-ansi-language: EN-GB; mso-bidi-font-family: 'Times New Roman'">
>From the response the harvester/crawler can see that its a file (protocol value = 'file:') or a service and - if service - make a subsequent GetCapabilities request which contains all further information? </span></div>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt">> For an output content model, as a WFS, we can offer a multitude of</p></font></font></span>
<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> output formats:</font></font></span></p>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> Data: OWSCommon (which is based on ISO19115/9), FGDC, DC</font></font></span>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> Services: OWSCommon (which is based on ISO19115/9)</font></font></span>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">Is there an UML diagram for both OWSCommon for data and services?</font></font>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-GB" style="mso-ansi-language: EN-GB"><font size="2"><font face="Courier New">> We can also provide an operation to a GeoRSS feed for 'most recent'</font>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><font size="2"><font face="Courier New">> entries.</font></font></p>
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<p class="MsoPlainText" style="MARGIN: 0cm 0cm 0pt"><span style="COLOR: black"><font size="2"><font face="Courier New">Yes.</font></font></span></p>