How to set zoom and center automatically based on GeoJSON features - openlayers-3

I load some features from .json file, and would like to automatically set view wuth zoom to see all loaded features. I user OpenLayers version 3.
Here's what I have:
var gjsonFile = new ol.layer.Vector({
source: new ol.source.GeoJSON({
url: 'map.json',
projection: 'EPSG:3857'
})
})
});
var map = new ol.Map({
view: new ol.View({
center: ol.proj.transform([-77.0087,38.8691], 'EPSG:4326', 'EPSG:3857'),
zoom: 12
}),
layers: [
new ol.layer.Tile({
source: new ol.source.OSM()
}),
gjsonFile
],
target: 'map1'
});

Vector sources have a #getExtent() method that gives you the extent of all features currently loaded in the source. To set the map's view to that extent as soon as the file is loaded, add the following code:
var source = gjsonFile.getSource();
var onChangeKey = source.on('change', function() {
if (source.getState() == 'ready') {
source.unByKey(onChangeKey);
map.getView().fitExtent(source.getExtent(), map.getSize());
}
});

Related

GML3 features Openlayers not plotting

Latest Version of Openlayers 3.
var metSource = new ol.source.Vector({
url: "metobjectxml/2.xml",
format: new ol.format.GML3({
defaultDataProjection: 'EPSG:4326'
})
});
var metLayer = new ol.layer.Vector({
source: metSource
});
var mapView = new ol.View({
center: ol.proj.transform([-114.3035, 54.5800], 'EPSG:4326', 'EPSG:900913'),
zoom: 5,
projection: 'EPSG:900913'
});
var map = new ol.Map({
layers: [metLayer],
target: 'map',
view: mapView
});
```
Not plotting anything.
XML file: https://bpaste.net/show/56363886838f
Anyone know why?
This is not supported by OpenLayers. Only GML simple features profile is supported. What you have seems sensor web related.

How to use features from Geojson in openlayers3?

I am using openlayers3 and i want to bring my features from feature.json, it seems when my map is loded I can get the feature file from network as xhr request but i am not able to see my polygons on map. Here below is my code
function showMap() {
var vector = new ol.layer.Vector({
projection: 'EPSG:5650',
source: new ol.source.Vector({
format: new ol.format.GeoJSON(),
projection: 'EPSG:5650',
url: 'feature.json'
})
});
var map = new ol.Map({
target: 'tilemap',
controls: ol.control.defaults({
attributionOptions: /** #type {olx.control.AttributionOptions} */ ({
collapsible: false
})
}),
layers: [
new ol.layer.Image({
source: new ol.source.ImageWMS({
url: 'http://www.geodaten-mv.de/dienste/adv_dop',
crossOrigin: null,
projection: 'EPSG:5650',
params: {
VERSION: '1.3.0',
LAYERS: 'mv_dop',
FORMAT: 'image/jpeg',
CRS: 'EPSG:5650'
}
})
}),vector
],
view: new ol.View({
projection: 'EPSG:5650',
center: [33355494, 5983295],
zoom: 10
})
});
DisplayTilesServices.setMap(map);
}
I was using olderversion of openlayers and now instead of Using url in source, now I am using features and it works!! see the code below
$http.get('feature.geojson').then(function(res){
var format = new ol.format.GeoJSON();
source=new ol.source.Vector({
projection: 'EPSG:5650',
features:format.readFeatures(res.data)
});
var vectorLayer = new ol.layer.Vector({
source: source
});
map.addLayer(vectorLayer);
},function(){})

OL3 Color Icon in KML

Now I am trying to migrate Google Earth to OpenLayers 3 (version 3.11.1)
I use a KML file, while viewing with GE, the icon is colored but with OL3, the color is not displayed
Here is my code snippet to post this KML file:
var projection = ol.proj.get('EPSG:3857');
var raster = new ol.layer.Tile({
source: new ol.source.BingMaps({
imagerySet: 'Aerial',
key: 'Ak-dzM4wZjSqTlzveKz5u0d4IQ4bRzVI309GxmkgSVr1ewS6iPSrOvOKhA-CJlm3'
})
});
var vector = new ol.layer.Vector({
source: new ol.source.Vector({
url: '/UsersFiles/KMLTest.kml',
format: new ol.format.KML({ extractStyles: true })
})
});
var map = new ol.Map({
layers: [raster, vector],
target: document.getElementById('map4'),
view: new ol.View({
center: [0 ,0],
projection: projection,
zoom: 0
})
});
the result is on the image below:
Icon in Google Earth
Icon in OL3

WFS layer not displayed in OL3 when loading as GeoJSON from geoserver

I am trying to load my layer from Geoserver as WFS layer in my OL3 application.
Here is my code to create WFS layer:
var vectorSource = new ol.source.Vector({
format: new ol.format.GeoJSON(),
url: function(extent, resolution, projection) {
return 'http://localhost:8080/geoserver/wfs?service=WFS&' +
'version=1.0.0&request=GetFeature&typename=main:Building_WGS&' +
'outputFormat=application/json&srsname=EPSG:4326&';
},
strategy: ol.loadingstrategy.tile(ol.tilegrid.createXYZ({
}))
});
var vector1 = new ol.layer.Vector({
source: vectorSource,
style: new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'rgba(0, 0, 255, 1.0)',
width: 2
})
})
});
To make my code complete here is the code where I have created map object:
var centerpos = [84.2, 28.2];
var newpos = ol.proj.transform(centerpos,'EPSG:4326','EPSG:900913');
var maxExtent = [80.05844110726194,26.34796712822462,88.2015218371264,30.44742963310623];
var map = new ol.Map({
layers: [baseLayerOSM, vector1],
target: 'map',
//controls: [new CustomControl()],
view: new ol.View({
extent:ol.proj.transformExtent(maxExtent, 'EPSG:4326', 'EPSG:900913'),
projection : 'EPSG:900913', // OSM projection
center : newpos,
minZoom:7,
zoom: 7
})
});
I can see the OSM layer in my map. But I can't see the layer Building_WGS. I have a workspace main in geoserver.
When I copy the URL
'http://localhost:8080/geoserver/wfs?service=WFS&' +
'version=1.0.0&request=GetFeature&typename=main:Building_WGS&' +
'outputFormat=application/json&srsname=EPSG:4326&';
I can see the JSON contents.
Can anyone suggest what am I doing wrong in my code?
I even tried to add crossOrigin:"Anonymous" but that doesn't help either.
HELP please
AJ

OpenLayers setting position of overlay on a static image

I have created a map with OpenLayers 3 using static image. It uses fake projection so the map can use to properly display the layer as it's measured in pixels. This is the code:
var pixelProjection = new ol.proj.Projection({
code: 'pixel',
units: 'pixels',
extent: [0, 0, 1389, 1070]
});
var map = new ol.Map({
layers: [
new ol.layer.Image({
source: new ol.source.ImageStatic({
url: 'http://s25.postimg.org/4o15oqbmn/jdgf.jpg',
imageSize: [1389, 1070],
projection: pixelProjection,
imageExtent: pixelProjection.getExtent()
})
})
],
target: 'map',
view: new ol.View2D({
projection: pixelProjection,
center: ol.extent.getCenter(pixelProjection.getExtent()),
zoom: 2
})
});
I was trying to add marker overlays to add some more interactions however I'm struggling to specify position and the markers is outside the map rather then inside where I want to place it.
var marker = new ol.Overlay({
position: [200, 200],
element: document.getElementById('marker'),
stopEvent: false
});
I'm very novice to this so if anyone have an idea how to set position correctly I will be thankful.
Using this OpenLayers 3 map as an example, I was able to add a marker to the center of your static image with the following:
var iconFeature = new ol.Feature({
geometry: new ol.geom.Point([700, 700])
});
var iconStyle = new ol.style.Style({
image: new ol.style.Icon({
src: 'http://ol3js.org/en/master/examples/data/icon.png'
})
});
iconFeature.setStyle(iconStyle);
var vectorSource = new ol.source.Vector({
features: [iconFeature]
});
var vectorLayer = new ol.layer.Vector({
source: vectorSource
});

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