I have this GeoJSON file (polygon.geojson)...

{
  "type": "Feature",
  "geometry": { "type": "Polygon", "coordinates": [ [ [73, 15], [83.0, 15], [83, 5], [73, 5], [73, 15] ] ] },
  "properties": { "name": "Foo" }
}

...and use it as vector source:

var vectorSource = new ol.source.Vector({
    url: 'polygon.geojson',
    format: new ol.format.GeoJSON(),
    projection : 'EPSG:4326',
});

Now I want to get the extent with:

var extent = vectorSource.getExtent();

The value of extent, however, is:

Array [ Infinity, Infinity, -Infinity, -Infinity ]

I'm using OL 3.9.0 and the vector layer with this source is displayed properly. What am I doing wrong?

I have this GeoJSON file (polygon.geojson)...

{
  "type": "Feature",
  "geometry": { "type": "Polygon", "coordinates": [ [ [73, 15], [83.0, 15], [83, 5], [73, 5], [73, 15] ] ] },
  "properties": { "name": "Foo" }
}

...and use it as vector source:

var vectorSource = new ol.source.Vector({
    url: 'polygon.geojson',
    format: new ol.format.GeoJSON(),
    projection : 'EPSG:4326',
});

Now I want to get the extent with:

var extent = vectorSource.getExtent();

The value of extent, however, is:

Array [ Infinity, Infinity, -Infinity, -Infinity ]

I'm using OL 3.9.0 and the vector layer with this source is displayed properly. What am I doing wrong?

• javascript
• openlayers-3

Share Improve this question Follow edited Sep 15, 2015 at 17:38 Mark asked Sep 15, 2015 at 11:49 MarkMark 51944 silver badges1313 bronze badges 3

• You could try to replace ol.js by ol-debug.js and step into the getExtent method to really see what's going on (using your browser Dev Tool). Maybe that could help. – Alexandre Dubé Commented Sep 15, 2015 at 12:10
• Sure you don't use the useSpatialIndex or call the method before the vector source has loaded any features? – Alvin Lindstam Commented Sep 15, 2015 at 14:16
• Maybe the data is not yet loaded when I want to calculate the extent (I noticed that the extent is set when I open the web console after the page has been loaded). How can I check if the data is ready loaded? – Mark Commented Sep 15, 2015 at 17:02

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3 Answers 3

Sorted by: Reset to default 11

I figured it out. I need to wait until the source is loaded:

vectorSource.once('change',function(e){
    if(vectorSource.getState() === 'ready') {
        var extent = vectorSource.getExtent();
        console.log(extent);
        map.getView().fit(extent, map.getSize());
    }
});

EDIT: It might be safer to zoom only if the layer isn't empty:

vectorSource.once('change',function(e){
    if(vectorSource.getState() === 'ready') { 
        if(layers[0].getSource().getFeatures().length>0) {
            map.getView().fit(vectorSource.getExtent(), map.getSize());
        }
    }
});

If you're looking to fit to the extent try this:

var extent = *YOURLAYER*.getSource().getExtent();
map.getView().fit(extent, map.getSize());

You could loop for each feature and create calculate bounds like this:

var bounds = ol.extent.createEmpty();
for(var i=0;i< features.length;i++){
ol.extent.extend(bounds,features[i].getGeometry().getExtent())
}

map.getView().fitExtend(bounds , map.getSize());