Ticket #2024 (closed feature: fixed)
GeoJSON + OpenStreetMap Projection problems for FeatureCollections
| Reported by: | ibolmo | Owned by: | crschmidt |
|---|---|---|---|
| Priority: | critical | Milestone: | 2.8 Release |
| Component: | Format.GeoJSON | Version: | 2.7 |
| Keywords: | Cc: | ||
| State: | Complete |
Description
Took a while to weed this bug out, but the problem is on line 223 of OpenLayers/GeoJSON.js
components[i] = this.parseGeometry.apply(
this, [obj.geometries[i]]
);
Coupled with lines 244-247:
if (this.internalProjection && this.externalProjection) {
geometry.transform(this.externalProjection,
this.internalProjection);
}
Basically,for GeometryCollections, each geometry is parsed with parseGeometry and then transformed. Eventually, the loop will end and the components are instantiated in a Geometry.Collection.
Because Geometry.Collections have their own transform method, each component will be transformed once again. This is the bug.
The solution is to return on line 227:
return new OpenLayers.Geometry.Collection(components);
So that the geometry collection is not (re)transformed.
Test Case:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<style type="text/css" media="screen">
#map { height: 500px; }
</style>
<script src="openlayers.js" type="text/javascript" charset="utf-8"></script>
<script src="http://www.openstreetmap.org/openlayers/OpenStreetMap.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript" charset="utf-8">
function init(){
var map = new OpenLayers.Map ("map", {
controls: [
new OpenLayers.Control.Navigation(),
new OpenLayers.Control.Attribution()
],
maxExtent: new OpenLayers.Bounds(-20037508.34,-20037508.34,20037508.34,20037508.34),
maxResolution: 156543.0399,
numZoomLevels: 19,
units: 'm',
projection: new OpenLayers.Projection("EPSG:900913"),
displayProjection: new OpenLayers.Projection("EPSG:4326")
});
var osm = new OpenLayers.Layer.OSM.Mapnik('OSM');
map.addLayer(osm);
var lonLat = new OpenLayers.LonLat(5, 40).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject());
map.setCenter (lonLat, 5);
var featurecollection = {
"type": "FeatureCollection",
"features": [{
"geometry": {
"type": "GeometryCollection",
"geometries": [
{
"type": "LineString",
"coordinates":
[[11.0878902207, 45.1602390564],
[15.01953125, 48.1298828125]]
},
{
"type": "Polygon",
"coordinates":
[[[11.0878902207, 45.1602390564],
[14.931640625, 40.9228515625],
[0.8251953125, 41.0986328125],
[7.63671875, 48.96484375],
[11.0878902207, 45.1602390564]]]
},
{
"type":"Point",
"coordinates":[15.87646484375, 44.1748046875]
}
]
},
"type": "Feature",
"properties": {}
}]
};
var geojson_format = new OpenLayers.Format.GeoJSON({
'internalProjection': new OpenLayers.Projection("EPSG:900913"),
'externalProjection': new OpenLayers.Projection("EPSG:4326")
});
var vector_layer = new OpenLayers.Layer.Vector();
map.addLayer(vector_layer);
vector_layer.addFeatures(geojson_format.read(featurecollection));
};
</script>
</head>
<body onload="init()">
<div id="map"></div>
</body>
</html>
Attachments
-
GeoJSON.patch
(0.5 KB) - added by ibolmo
4 years ago.
Change History
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