openlayers/ol3 — pull request #1548 by fredj (2014-01-20 08:14:17+00:00)
Title: Add readFeatures and readProjection options to ol.format.JSON

To be able to create custom `ol.format.JSON` format.

For example, to read elasticsearch query results:
```javascript
var source = new ol.source.VectorFile({
url: '...',
format: new ol.format.JSON({
readFeatures: function(object) {
var features = [];
var hits = object.hits.hits;

for (var i = 0, ii = hits.length; i < ii; i++) {
var hit = hits[i];
var feature = new ol.Feature();
var geom = new ol.geom.Point(hit._source.geoip.location);
feature.setGeometry(geom);
features.push(feature);
}
return features;
},
readProjection: function(object) {
return ol.proj.get('EPSG:4326');
}
})
});
```