[OpenLayers-Trac] Re: [OpenLayers] #3495: GPX writer

[OpenLayers]

#3495: GPX writer
---------------------+------------------------------------------------------
 Reporter:  pgiraud  |       Owner:              
     Type:  feature  |      Status:  new         
 Priority:  minor    |   Milestone:  2.12 Release
Component:  general  |     Version:  2.11 RC3    
 Keywords:           |       State:  Commit      
---------------------+------------------------------------------------------
Changes (by marcjansen):

  * state:  Review => Commit


Comment:

 Pierre,

 good to have write support for GPX thanks to your work. Please commit your
 latest patch.

 One question, though. While looking into your patch I wrote another
 testcase, that is currently failing:

 {{{
 function test_Format_GPX_serialize_deserialize(t) {
         t.plan(3);
         var parser = new OpenLayers.Format.GPX();

         // create a polygon and serialize it
         var point = new OpenLayers.Geometry.Point(-111.04, 45.68);
         var point2 = new OpenLayers.Geometry.Point(-112.04, 45.68);
         var linearRing = new OpenLayers.Geometry.LinearRing([point,
 point2, point.clone()]);
         var polygon = new OpenLayers.Geometry.Polygon([linearRing]);
         var f = new OpenLayers.Feature.Vector(polygon, {name: 'foo',
 description: 'bar'});
         var data = parser.write([f]);

         // now deserialize the GPX and compare with the input values
         var deserialized = parser.read(data);
         console.log(deserialized);
         t.eq(deserialized.length, 1,
             'Serialized GPX string returned exactly one element on
 deserialisation.');
         t.ok(deserialized[0] instanceof OpenLayers.Feature.Vector,
             'Serialized GPX string returned exactly one feature on
 deserialisation.');
         // This fails as the track is returned as a linestring
         t.ok(deserialized[0].geometry instanceof
 OpenLayers.Geometry.Polygon,
             'Serialized GPX string returned exactly one feature with
 polygon geometry on deserialisation.');
     }
 }}}

 (This is essentially your `test_Format_GPX_serialize_polygon(t)` only with
 an added deserialisation)

 When the GPX string is deserialized, the information that it once was a
 polygon is lost. One might expect that any write operation should lead on
 subsequent reading to the same input values. But in the particular case I
 doubt whether that would make sense (You would most possibly not expect
 your GPX of a roundtrip to be interpretted as a polygon, right?).

 What do you think?

-- 
Ticket URL: <http://trac.openlayers.org/ticket/3495#comment:3>
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