How to display the latitude and longitude in from this code using Openlayers?

Question

<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta name="viewport" content="width=device-width; initial-scale=1.0; maximum-scale=1.0; user-scalable=0;" />
    <meta name="apple-mobile-web-app-capable" content="yes" />
        <title>Drag Feature Example</title>

        <link rel="stylesheet" href="../theme/default/style.css" type="text/css" />
        <link rel="stylesheet" href="style.css" type="text/css" />
        <style type="text/css">
            #controls {
                width: 512px;
            }
            #controlToggle {
                padding-left: 1em;
            }
            #controlToggle li {
                list-style: none;
            }
        </style>

        <script src="../OpenLayers.js"></script>
        <script type="text/javascript">
            var map, vectors, controls;
            function init(){
                map = new OpenLayers.Map('map');
                var wms = new OpenLayers.Layer.WMS( "OpenLayers WMS",
                    "http://vmap0.tiles.osgeo.org/wms/vmap0?", {layers: 'basic'});

                vectors = new OpenLayers.Layer.Vector("Vector Layer");

                map.addLayers([wms, vectors]);
                map.addControl(new OpenLayers.Control.LayerSwitcher());
                map.addControl(new OpenLayers.Control.MousePosition());
        //map.addControl(new OpenLayers.Control.Click());

                controls = {
                    point: new OpenLayers.Control.DrawFeature(vectors,
                                OpenLayers.Handler.Point),

                    line: new OpenLayers.Control.DrawFeature(vectors,
                                OpenLayers.Handler.Path),
                    polygon: new OpenLayers.Control.DrawFeature(vectors,
                                OpenLayers.Handler.Polygon),
                    drag: new OpenLayers.Control.DragFeature(vectors)
                };

                for(var key in controls) {
                    map.addControl(controls[key]);
           // map.addControl(click);
            }

                map.setCenter(new OpenLayers.LonLat(0, 0), 3);
                document.getElementById('noneToggle').checked = true;
            }

            function toggleControl(element) {
                for(key in controls) {
                    var control = controls[key];
                    if(element.value == key && element.checked) {
                        control.activate();
                    } else {
                        control.deactivate();
                    }
                }
            }
        </script>
    </head>
    <body onload="init()">
        <h1 id="title">Drag Feature Example</h1>

        <div id="tags">
            point, line, linestring, polygon, digitizing, geometry, draw, drag
        </div>

        <p id="shortdesc">
            Demonstrates point, line and polygon creation and editing.
        </p>

        <div id="map" class="smallmap"></div>

        <div id="controls">
            <ul id="controlToggle">
                <li>
                    <input type="radio" name="type" value="none" id="noneToggle"
                           onclick="toggleControl(this);" checked="checked" />

                    <label for="noneToggle">navigate</label>
                </li>
                <li>
                    <input type="radio" name="type" value="point" id="pointToggle" onclick="toggleControl(this);" />
                    <label for="pointToggle">draw point</label>
                </li>
                <li>
                    <input type="radio" name="type" value="line" id="lineToggle" onclick="toggleControl(this);" />

                    <label for="lineToggle">draw line</label>
                </li>
                <li>
                    <input type="radio" name="type" value="polygon" id="polygonToggle" onclick="toggleControl(this);" />
                    <label for="polygonToggle">draw polygon</label>
                </li>
                <li>
                    <input type="radio" name="type" value="drag" id="dragToggle"
                           onclick="toggleControl(this);" />

                    <label for="dragToggle">drag feature</label>
                </li>
            </ul>
        </div>

        <div id="docs"></div>
    </body>
</html>

I want to display the latitude and longtiude of every mouse click in a text box. I am not able to understand from where I should derive the latitude and longitude?

Have you seen this example : http://openlayers.org/dev/examples/click.html ? (They have a lot of example there http://openlayers.org/dev/examples/ — j_freyre, Feb 28 '11 at 09:41
I have . I want to figure out in this code , where exactly does the LATLONG show up . I am trying to understand this code — Hick, Feb 28 '11 at 09:43

Fran Verona · Answer 1 · 2011-02-28T13:40:51.020

This is what you need:

map.events.register("click", map, function(e) {
  var position = map.getLonLatFromPixel(e.xy);

  OpenLayers.Util.getElement("mydiv").innerHTML = 
        position.lon.toFixed(3) + ', ' + position.lat.toFixed(3);

});

You can see here the code working: http://jsbin.com/uyuka6

So, your code should looks:

function init(){

      var map, vectors, controls;
      map = new OpenLayers.Map('map');
      var wms = new OpenLayers.Layer.WMS( "OpenLayers WMS",
        "http://vmap0.tiles.osgeo.org/wms/vmap0?", {layers: 'basic'});

      vectors = new OpenLayers.Layer.Vector("Vector Layer");

      map.addLayers([wms, vectors]);
      map.addControl(new OpenLayers.Control.LayerSwitcher());
      map.addControl(new OpenLayers.Control.MousePosition());
      //map.addControl(new OpenLayers.Control.Click());

      map.events.register("click", map, function(e) {
         var position = map.getLonLatFromPixel(e.xy);

         OpenLayers.Util.getElement("shortdesc").innerHTML =
             position.lon.toFixed(3) + ', ' + position.lat.toFixed(3);

      });

      controls = {
           point: new OpenLayers.Control.DrawFeature(vectors,
             OpenLayers.Handler.Point),

           line: new OpenLayers.Control.DrawFeature(vectors,
             OpenLayers.Handler.Path),
           polygon: new OpenLayers.Control.DrawFeature(vectors,
             OpenLayers.Handler.Polygon),
           drag: new OpenLayers.Control.DragFeature(vectors)
       };

       var poly = controls['polygon'].handler;
       poly.callbacks.point = function(point){
           OpenLayers.Util.getElement("docs").innerHTML = point.toString();
       };

       var line = controls['line'].handler;
       line.callbacks.point = function(point){
          OpenLayers.Util.getElement("docs").innerHTML = point.toString();
       };

       for(var key in controls) {
          map.addControl(controls[key]);
          // map.addControl(click);
       }

       map.setCenter(new OpenLayers.LonLat(0, 0), 3);
       document.getElementById('noneToggle').checked = true;
}

@mekasperasky What is exactly don't working? You should add the previous code into your init() function (after 'control' initialization variable) — Fran Verona, Feb 28 '11 at 10:06
Can you repost the code with your edit to it ? I did what you asked and it is deactivating the other mouse events like point , or line . — Hick, Feb 28 '11 at 10:11
It is not working for Points and lines . That is the problem . Try the code that I have posted and ouput the lat and long for points I draw a line in — Hick, Feb 28 '11 at 10:27
@mekasperasky I edited my own code. I hope it helps you now. You can see it online in JSBin http://jsbin.com/epire5 — Fran Verona, Feb 28 '11 at 13:44
I get relaly long lines, like -6509037.608. This doesn't solve my issue. — fotanus, Jan 31 '13 at 20:59
without getting too involved in your question, I was getting similarly strange coordinates. It might be that you need to transform the points to the right projection. See: http://stackoverflow.com/questions/2601745/how-to-convert-vector-layer-coordinates-into-map-latitude-and-longitude-in-openl — dbjohn, Feb 10 '13 at 23:23

How to display the latitude and longitude in from this code using Openlayers?

1 Answers1