Use-Cases update

Éric Lemoine
2013-03-27 15:51:54 +01:00
parent e2fde088d6
commit 8aab66ff77
+39
@@ -86,6 +86,45 @@ vector.addFeatures(parser, {
In this alternative, the vector layer has no source set - meaning the user will be manually generating features. This alternative can be implemented if the layer knows about the map projection. In the `addFeatures` method, the layer calls `parser.readFeatures(data, {projection: projection})` where `data` is the first argument to `addFeatures` and `projection` is the map view's projection.
_Questions/comments from Eric:_
In my alternative, and based on my comments for the previous use-case, the app would add features to the store.
** Alternative 2**
var vector = new ol.layer.Vector({
source: new ol.source.Vector({
projection: 'EPSG:4326'
})
});
var map = new ol.Map({
target: 'map',
layers: [vector]
view: new ol.View2D({
projection: 'EPSG:1234',
center: ol.projection.transform(
new ol.Coordinate(-111, 45), 'EPSG:4326', 'EPSG:1234'),
zoom: 3
})
});
var parser = new ol.parser.GeoJSON();
vector.getSource().addFeatures(parser, {
type: 'FeatureCollection',
features: [{
type: 'Feature',
geometry: {
type: 'Point',
coordinates: [-111, 45]
},
properties: {
foo: 'bar'
}
}]
});
### Load data based on map extent
User has a service that provides vector features for requests with an arbitrary BBOX (e.g. a WFS). Data source contains hundreds of millions of features with worldwide coverage (e.g. OSM) and the user only wants to display a small subset, updating rendered features as the user navigates around the map.