[OpenLayers-Trac] [OpenLayers] #1531: add a convenience method to create one stylemap that can hold different symbolizers for points, lines and polygons

[OpenLayers]

#1531: add a convenience method to create one stylemap that can hold different
symbolizers for points, lines and polygons
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  Reporter:  ahocevar  |       Owner:  ahocevar   
      Type:  task      |      Status:  new        
  Priority:  minor     |   Milestone:  2.7 Release
 Component:  Style     |     Version:  2.6        
Resolution:            |    Keywords:             
     State:  Review    |  
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Changes (by ahocevar):

  * state:  Needs Discussion => Review

Comment:

 1531-!r7060-A0.patch does significantly more than what I proposed in the
 original ticket description:

  * Implemented a new geometryType property for OpenLayers.Rule. This
 property can be set to determine for which geometry types (i.e. lines,
 points, polygons) the rule should apply.

  * Added support for FeatureTypeStyle and SemanticTypeIdentifier in
 OpenLayers.Format.SLD. For SLD.write, every geometry type that is found in
 the rules' geometryType properties will be assigned to a separate
 FeatureTypeStyle with the geometry type as SemanticTypeIdentifier.
 SLD.read will read SemanticTypeIdentifier, analyzes it and sets the
 appropriate geometry type. This works for SemanticTypeIdentifiers that
 address the geometry type (i.e. generic:point, generic:line and
 generic:polygon, according to the SLD spec).

  * Added a convenience method makeGeometryTypeAware() to
 OpenLayers.!StyleMap. This will allow users who pack symbolizers that
 should only apply to point, line or polygon features into a single rule to
 convert those symbolizers to appropriate rules with geometryType

 The whole idea of this patch is to meet both requirements of specifying
 symbolizers according to SLD's PointSymbolizer, LineSymbolizer and
 PolygonSymbolizer (a PointSymbolizer applied to a polygon means e.g. to
 draw a point symbol in the centroid point of a polygon), and to define
 different styles for different geometry types according to SLD's
 SemanticTypeIdentifier (i.e. apply a rule only if the feature's geometry
 type matches the rule's geometryType).

 Note that rendering e.g. polygons with a point symbol is not supported yet
 in OpenLayers, but once that will happen, this patch gives us the API for
 it.

 The patch includes tests for the new features. All tests pass in FF2 and
 IE6. Any review will be appreciated.

-- 
Ticket URL: <http://trac.openlayers.org/ticket/1531#comment:1>
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