[fusion-trac] #137: Support multiple hosts for tile maps

[Fusion]

#137: Support multiple hosts for tile maps
---------------------------+------------------------------------------------
   Reporter:  jbirch       |       Owner:  madair  
       Type:  enhancement  |      Status:  assigned
   Priority:  P2           |   Milestone:  2.3     
  Component:  Widgets      |     Version:  SVN     
   Severity:  Major        |    Keywords:          
External_id:               |       State:  New     
    Browser:  All          |          Os:  All     
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Changes (by madair):

  * milestone:  2.2 => 2.3


Comment:

 it appears that this is already supported in Fusion/OpenLayers, but only
 for static tilecache as opposed to retrieving tiles from the MapGuide
 server.

 The way to configure it is:

 1. in config.json, set the mapguide/tileCacheUrl with an array of strings,
 which are the hosts that are serving up the tiles, e.g.:

 "tileCacheUrl":
 ["http://host01/sheboygan","http://host02/sheboygan","http://host03/sheboygan"]

 2. use the OL MapGuide layer useHttpTile option.  Set this in the <Map>
 element extension like so:

       <Map xsi:type="MapGuideLayerType">
         <Type>MapGuide</Type>
         <SingleTile>false</SingleTile>
         <Extension>
 <ResourceId>Library://Samples/Sheboygan/MapsTiled/Sheboygan.MapDefinition</ResourceId>
           <Options>
             <useHttpTile>true</useHttpTile>
           </Options>
         </Extension>
       </Map>

 And you should get your tiles pulled randomly from all the servers in the
 array.  I don't have a setup to fully test this but in Firebug I can see
 that tiles are being requested from the 3 servers (with 404 responses
 since I don't actually have anything at those URLs).

 Supporting this mechanism with tiles served from the MapGuide server would
 require some coding changes but is viable.  Is that something that should
 be done?  I suspect most production sites would build a pre-seeded tile
 cache.

 In any case, bumping this to 2.3 since it already works for the most part
 or close the ticket if the above is sufficient.

-- 
Ticket URL: <http://trac.osgeo.org/fusion/ticket/137#comment:3>
Fusion <http://trac.osgeo.org/fusion>
Fusion is a web-mapping application development framework for MapServer and MapGuide OS.