[OpenLayers-Trac] [OpenLayers] #1531: add support for geometry type aware styling rules

[OpenLayers]

#1531: add support for geometry type aware styling rules
-------------------------------+--------------------------------------------
  Reporter:  ahocevar          |       Owner:  ahocevar
      Type:  feature           |      Status:  new     
  Priority:  minor             |   Milestone:  Future  
 Component:  Style             |     Version:  2.6     
Resolution:                    |    Keywords:          
     State:  Needs Discussion  |  
-------------------------------+--------------------------------------------
Changes (by ahocevar):

  * state:  Needs More Work => Needs Discussion
  * milestone:  2.7 Release => Future

Comment:

 Ok, after tschaub's suggestion of allowing functions as symbolizers, a
 little more thoughts about that. Currently, a symbolizer can have values
 or property names for its values, e.g.
 {{{
 var symbolizer = {
     strokeColor: "blue",
     fillColor: "${fill}"
 }
 }}}
 In the future, we could add a third way to define symbolizer values:
 {{{
 var symbolizer = {
     strokeColor: function(feature) {
         switch(feature.state){
             "Insert": return "green";
             "Update": return "yellow";
             "Delete": return "red";
             default: return "gray";
         }
 }
 }}}
 This is similar to what tschaub proposed (allow a function as symbolizer),
 just the other way around. With that, we have almost everything we need to
 implement ogc:Function. What we still need is a function factory that
 creates the correct functions with closures for the parameters when
 deserializing SLD or ogc:Filter. Those functions can then be attached to a
 feature.

 The only concern with that is performance: calling functions is slow, and
 we might have to call a lot of functions if every symbolizer property is
 created by a function.

 Anyway, that's just a few thoughts, discussion of a larger picture of all
 that might be in order.

-- 
Ticket URL: <http://trac.openlayers.org/ticket/1531#comment:5>
OpenLayers <http://openlayers.org/>
A free AJAX map viewer