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| MapServer + PostGIS + pgRouting + OpenLayers |
Showing posts with label openlayers. Show all posts
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| Geojson |
Let's see how we can add a vector layer to OpenLayers map with the help of GeoJSON response received from the server. Web Server can produce response in GML, GeoJSON, XML...etc after running a spatial query.
OpenLayers has Format classes for interpreting each kind of response.
This response consists of raw data which should be converted to features and added to a vector layer in order to render with OpenLayers.
var newLayer = new OpenLayers.Layer.Vector("Filtered by Zoom Level", {
strategies: [new OpenLayers.Strategy.BBOX(),
],
protocol: new OpenLayers.Protocol.HTTP({
url: "http://localhost/test/a.php?start=79.891119%207.078768&end=81.000609%207.940130&method=SPD",
format: new OpenLayers.Format.GeoJSON({
externalProjection: new OpenLayers.Projection("EPSG:4326"),
internalProject: new OpenLayers.Projection("EPSG:900913")
})
}),
//filter: filter,
// styleMap: styleMap,
format: new OpenLayers.Format.GeoJSON({
externalProjection: new OpenLayers.Projection("EPSG:4326"),
internalProject: new OpenLayers.Projection("EPSG:900913")
})
});
map.addLayers([newLayer]);
Another Way
var newLayer = new OpenLayers.Layer.Vector("SPD", {
isBaseLayer: false,
styleMap: new OpenLayers.StyleMap({'default':{
strokeColor: "#F00",
strokeOpacity: 1,
strokeWidth: 2,
fillColor: "#FF5500",
fillOpacity: 0.5,
label : "${ad}",
fontSize: "8px",
fontFamily: "Courier New, monospace",
labelXOffset: "0.5",
labelYOffset: "0.5"
}})
});
OpenLayers.Request.GET({
url: "http://localhost/test/a.php?start=79.891119%207.078768&end=81.000609%207.940130&method=SPD",
headers: {'Accept':'application/json'},
success: function (req)
{
var g = new OpenLayers.Format.GeoJSON();
var feature_collection = g.read(req.responseText);
newLayer.destroyFeatures();
newLayer.addFeatures(feature_collection);
}
});
map.addLayers([newLayer]);
Demo
[sourcecode language="javascript"]
<script src="http://openlayers.org/api/OpenLayers.js"></script>
<script type="text/javascript">
function init(){
map = new OpenLayers.Map('map');
base_layer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
"http://labs.metacarta.com/wms/vmap0", {layers: 'basic'} );
map.addLayer(base_layer);
map.setCenter(new OpenLayers.LonLat(79.8333,6.9167),7);
var markers = new OpenLayers.Layer.Markers( "Markers" );
map.addLayer(markers);
var size = new OpenLayers.Size(21,25);
var offset = new OpenLayers.Pixel(-(size.w/2), -size.h);
var icon = new OpenLayers.Icon('http://www.openlayers.org/dev/img/marker.png', size, offset);
markers.addMarker(new OpenLayers.Marker(new OpenLayers.LonLat(79.8333,6.9167),icon));
markers.addMarker(new OpenLayers.Marker(new OpenLayers.LonLat(79.8333,6.9167),icon.clone()));
marker = new OpenLayers.Marker(new OpenLayers.LonLat(79.8333,6.9167));
markers.addMarker(marker);
marker.events.register("click", marker, function(e){
popup = new OpenLayers.Popup.FramedCloud("chicken",
new OpenLayers.LonLat(79.8333,6.9167),
new OpenLayers.Size(200, 200),
"I was here <br><img src='uploads/me.png' width='90' height='90'>",
null, true);
map.addPopup(popup);
});
}
</script>
</head>
<body onLoad="init()">
<div id="map" style="width:500px;height:300px;margin-left: auto;margin-right:auto;"></div>
[/sourcecode]
[sourcecode language="javascript"]
<script src="http://openlayers.org/api/OpenLayers.js"></script>
<script type="text/javascript">
function init(){
map = new OpenLayers.Map('map');
base_layer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
"http://labs.metacarta.com/wms/vmap0", {layers: 'basic'} );
map.addLayer(base_layer);
map.setCenter(new OpenLayers.LonLat(79.8333,6.9167),7);
var markers = new OpenLayers.Layer.Markers( "Markers" );
map.addLayer(markers);
var size = new OpenLayers.Size(21,25);
var offset = new OpenLayers.Pixel(-(size.w/2), -size.h);
var icon = new OpenLayers.Icon('http://www.openlayers.org/dev/img/marker.png', size, offset);
markers.addMarker(new OpenLayers.Marker(new OpenLayers.LonLat(79.8333,6.9167),icon));
markers.addMarker(new OpenLayers.Marker(new OpenLayers.LonLat(79.8333,6.9167),icon.clone()));
marker = new OpenLayers.Marker(new OpenLayers.LonLat(79.8333,6.9167));
markers.addMarker(marker);
marker.events.register("click", marker, function(e){
popup = new OpenLayers.Popup.FramedCloud("chicken",
new OpenLayers.LonLat(79.8333,6.9167),
new OpenLayers.Size(200, 200),
"I was here <br><img src='uploads/me.png' width='90' height='90'>",
null, true);
map.addPopup(popup);
});
}
</script>
</head>
<body onLoad="init()">
<div id="map" style="width:500px;height:300px;margin-left: auto;margin-right:auto;"></div>
[/sourcecode]
Demo
[sourcecode language="javascript"]
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Getting the coordinates of a click in OpenLayers Map</title>
<script src="http://openlayers.org/api/OpenLayers.js"></script>
<script type="text/javascript">
function init(){
map = new OpenLayers.Map('map');
base_layer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
"http://labs.metacarta.com/wms/vmap0", {layers: 'basic'} );
map.addLayer(base_layer);
map.setCenter(new OpenLayers.LonLat(79.8333,6.9167),7);
map.events.register('click', map, handleMapClick);
}
function handleMapClick(evt)
{
var lonlat = map.getLonLatFromViewPortPx(evt.xy);
alert("latitude : " + lonlat.lat + ", longitude : " + latitude);
}
</script>
</head>
<body onLoad="init()">
</body>
</html>
[/sourcecode]
[sourcecode language="javascript"]
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Getting the coordinates of a click in OpenLayers Map</title>
<script src="http://openlayers.org/api/OpenLayers.js"></script>
<script type="text/javascript">
function init(){
map = new OpenLayers.Map('map');
base_layer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
"http://labs.metacarta.com/wms/vmap0", {layers: 'basic'} );
map.addLayer(base_layer);
map.setCenter(new OpenLayers.LonLat(79.8333,6.9167),7);
map.events.register('click', map, handleMapClick);
}
function handleMapClick(evt)
{
var lonlat = map.getLonLatFromViewPortPx(evt.xy);
alert("latitude : " + lonlat.lat + ", longitude : " + latitude);
}
</script>
</head>
<body onLoad="init()">
</body>
</html>
[/sourcecode]
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