tommy's scratchpad

Check it out.  A few RFCs addressed, among them OGC WMS 1.3.0 server support.

Fresh in svn trunk, MapServer now has WMS 1.3.0 Server support and will be part of the forthcoming 5.4 release.

It will interesting to see the use WMS 1.3.0 gets, given the significant changes from 1.1.1.

Great work Assefa!

This has seemingly been the theme for me in the last few weeks.  From publishing to discovery, lack of metadata in OWS endpoints results in increased metadata management away from source, as well as crappy search results.

So here’s some friendly advice:

Service Metadata

• fill out title, abstract (representative of the OWS as a whole) with descriptive metadata
• fill out keywords to categorize the service.  If possible, use a known thesaurus, or one specific to your organization.  Don’t use keywords like “OGC”; we already know it’s an OGC service from the get-go by interacting with it
• fill out contact information.  OWS Common defines ServiceProvider metadata constructs, so if your organization has a service provider dishing out your OWS, they belong in this metadata.  This is a contact person for the service itself, not the data
• fill out Fees and AccessConstraints.  If there aren’t any, use the term “None”
• the OnlineResource for Service Metadata might be some website, not the URL of the service itself (we already get this from the OperationsMetadata)

Content Metadata

• fill in title, abstract and keywords in the same manner as above, specific to the given Layer/FeatureType/Coverage/ObservationOffering.  A title like “ROAD_1M” doesn’t cut it
• your data comes with an FGDC or ISO 19115 XML document already, right?  🙂 Use MetadataURL to point to the XML document.  Smart catalogues will harvest this too and associate it with the resource
• WMS DataURL: if the data can be downloaded online (tgz/zip/etc.), point to it here.  Or, put a pointer to an access service like WFS/WCS/SOS
• WMS Layer Attribution: this provides reference to the content provider (URL, title and LogoURL).  Filling in LogoURL is neat as catalogues can display this when users search for content.  If possible, use an image of smaller dimensions so as to display as a thumbnail
• Last but not least, bounding boxes.  Whether your OWS software automagically calculates these per layer on the fly, or you can override these and set before runtime, please set spatial extents accordingly.  This improves searching spatially by leaps and bounds.  Don’t settle for the often used default of -180, -90, 180, 90 unless it is really a global dataset

From here, OGC Catalogues will be able to harvest your metadata and provide useful search results.  For wider spread discovery, throw an OpenSearch definition in front of your CSW.  Wrap your OWS endpoints in KML/GeoRSS documents (Geo Sitemaps too), and you’ll power mainstream use of your stuff.

Funeral news from newrestfunerals.co.uk said:
‘Mourners buried under a bridge for the lost’

A group of members of London’s funeral procession paid their respects to a man and his mother at the Royal Greenwich Cathedral where they lost a loved one to cancer

The two sisters and their daughter, who was buried the same night, were buried at the Royal Greenwich Cathedral, where he passed away last weekend.

Grieve: The two sisters and their daughter, who was buried the same night, were buried at the Royal Greenwich Cathedral, where he passed away last weekend

At the bottom of the stairs of the church, you can see a cemeterie. It looked like an Indian wedding feast to the first group and there were candles and flowers on the ceiling.

The funeral family were in their homes in London but only a brief family procession was in progress.

The group had gathered in a cemeterie outside the cathedral and the coffin was handed over to the funeral director.

The funeral director also handed in to the British Transport Police and they placed the coffin in a safe house at Queen’s Park, New York.

The couple went to the funeral home and their body was found on the day of the operation.

Casket search: ‘Mourners raised at arms pace’

No word on a cause of death or why they died but the couple’s family said in a statement.

Bye bye useless searches!

For years in the CGDI, we’ve had various ‘common’ services; basic XML over HTTP / OGC-ish web services which allow a user to lookup and geocode based on different Canadian spatial identifiers, or keywords.  In their first life (mid 1990s), these existed as embedded lookup tools to facilitate searching and publishing in the GeoConnections Discovery Portal (GDP), then called Canadian Earth Observation Network (CEONet).

CEONet started to publish reusable components (RUCs), which allowed a developer to create an HTML template with special tags to embed these RUCs so as to spatially enable their applications.  Because of the JavaScript security model, the developer passed the template to the CEONet RUC server, which slurped the template and served it up from its own domain.

In both iterations, the backends were driven by database or HTML scrapes which outputted CSV-ish type output.

Since v3, (2001-ish) and the rise of Web Services, these RUCs became services themselves, thereby eliminating the need to go through GDP.

If I had a dime every time someone asked about middleware tools to be able to interact with these services, well….At any rate, the typical approach was as follows:

• setup HTML form with input parameters
• send request to middleware
• middleware invokes web services request, gets result, spits back HTML accordingly to the user

I’ve done these in many different languages.  For awhile, one of our projects had bundled a spatial clients .war which Java developers can plop into their webapps.

These days, using OpenLayers and jQuery lets you develop light, interactive ways of accomplishing this without server side middleware.  Trying this against the CGDI NTS Lookup Service provides a neat example:

<form id="ntsForm" action="javascript:zoomToNTS();">

 <label for="nts">NTS Mapsheet:</label>

 <input type="text" name="nts" id="nts" size="6" maxlength="6"/>

</form>

And now the JavaScript:

function zoomToNTS() {
  // build request URL
  url = '/mapbuilder/server/php/proxy.php?url=' + // simple proxy script
  escape('http://geoservices.cgdi.ca/NTS/NTSLookup?') +
  escape('version=1.1.0&request=GetMapsheet&mapsheet=') +
  jQuery('input#nts').val();

  // send and process result
  jQuery.get(url,{},function(xml){
    // get the bbox of the result
    jQuery('gml\\:boundedBy',xml).each(function(i) {
      c = jQuery(this).find('gml\\:coordinates').text().split(',');
      map.zoomToExtent(new OpenLayers.Bounds(c[0], c[1], c[2], c[3]));
    });
  });
}

That’s it!  That will get your OpenLayers map zoomed in based on the NTS boundaries.  Notes:

• you’ll need a proxy script to deal with remote URLs
• you need to escape namespace’d XML elements/attributes per above, possibly wrapping into a function for reuse.  Same goes for elements seperated with ‘.’ (like <foo.bar>)

Anyone have suggestions on improving the example above?  Or any similar snippets?  It would be nice to build up plugins like this for gazetteers, catalogs, and the like.