[Requests] Flexible and open URL templating for RESTful WMTS

Joan Maso joan.maso at uab.es
Wed Apr 1 13:43:51 EDT 2009


A


1. Evaluator:
        Joan Masó joan.maso at uab.es

2. Submission: 07-057 Candidate to Web Map Tiling Service



PART B


1. Requirement: REST Encoding modification


2. Implementation Specification Section number: [7.2.2]


3. Criticality: Major


4. Comments/justifications for changes:
A propose to accept flexible and open URL templating
and document it on the ServiceMetadata document.

I have demonstrated on the "Google maps emulator" that
it is possible to easily use several URL patterns in
a single client (WMTS and Google patterns) if the semantics
of the parameters is compatible.

A totally flexible pattern can be coded as a "search and
replace" function over the string URL.

WMTSr6:
HTTPServer/WMTSServerPath/{version}/{layer}/{style}/{firstDimensions}/.../{lastDimensions}/{TileMatrixSet}/{TileMatrix}/{TileRow}/{TileCol}.{format_extension}
Google becomes automatically a WMTS RESTful service:
HTTPServer/WMTSServerPath/hl=en&t={layer}&q={style}&z={TileMatrix}&y={TileRow}&x={TileCol}

Almost no performance side effects.

We need a new section on the Capabilities document:

ResourceMetadata that Describes the resource types
Resources are: tiles,FeatureInfos ..
The URL template is.

This gives the service addressability and some
degree of connectness.

This DO NOT interfere with Contents section. It complements it.
Contents deals with resources instances
Layer: coastlines, digitalElevation

In the URL template {layer} means one of the layer\ows:identifier values in 
Content section.

A possible way of doing this is:

 <ResourcesMetadata>
  <Resource name="ServiceMetadata">
   <Operations>
    <ows:Operation name="GetResourceRepresentation">
     <ows:DCP><ows:HTTP>
       <ows:Get 
xlink:href="http://www.miramon.uab.es/wmts/1.0.0/GetCapabilities.xml" />
     </ows:HTTP></ows:DCP>
    </ows:Operation>
   </Operations>
  </Resource>
  <Resource name="Tile">
   <Operations>
    <ows:Operation name="GetResourceRepresentation">
     <ows:DCP><ows:HTTP>
       <ows:Get 
xlink:href="http://www.miramon.uab.es/wmts/{layer}/{style}/{firstDimension}/.../{lastDimension}/{TileMatrixSet}/{scale}/{TileRow}/{TileCol}.{format_extension}" 
/>
     </ows:HTTP></ows:DCP>
    </ows:Operation>
   </Operations>
  </Resource>

I has commented in the service subcomitte meeting of the OGC TC in Athens 
and there where no
objections to that.

This request complements a previous one of sean.gillies at gmail.com

Joan Maso
UAB-CREAF-MiraMon 



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