mapserver.js

// Parameters to be passed either from config file or some other source
var mapPath="/cgi-bin/mapserv?map=/home/mark/htdocs/sandbox/contra_costa/mapdata/ccc.map";
var map, base;

function initMap(obj){
  var maxBounds=obj;
  var extent = new OpenLayers.Bounds(maxBounds[0], maxBounds[1], maxBounds[2], maxBounds[3]);
  var options = {
    restrictedExtent: extent
  };
  map = new OpenLayers.Map( 'map', options );
  base = new OpenLayers.Layer.WMS("Contra Costa County",
                  mapPath,
                  {
                    layers: 'county,city,water,landmarks,roads'
                  },
                  {
                    isBaseLayer: true,
                    maxResolution: "auto",
                    maxExtent: extent
                  });
  var sirens = new OpenLayers.Layer.Vector("CWS Sirens",
                       {
                     strategies: [new OpenLayers.Strategy.Fixed()],
                         protocol: new OpenLayers.Protocol.HTTP({
                         url: "./sirens.kml",
                         format: new OpenLayers.Format.KML(
                         {
                           extractStyles: true,
                           extractAttributes: true,
                           maxDepth: 1
                         })
                       })
                       });
  var tens = new OpenLayers.Layer.WMS( "TENS Zones",
                    mapPath,
                    {
                      layers: 'tens',
                      transparent: true
                    }, {
                      isBaseLayer: false
                    });
  tens.setVisibility(false);

  map.addLayers([base,sirens,tens]);

  select = new OpenLayers.Control.SelectFeature(sirens);
  sirens.events.on({
    "featureselected": onFeatureSelect,
    "featureunselected": onFeatureUnselect
  });
  map.addControl(select);
  map.addControl(new OpenLayers.Control.MousePosition());
  map.addControl(new OpenLayers.Control.LayerSwitcher());
  select.activate();
  map.zoomToMaxExtent();
}

function changeOption(obj) {
  var newBounds = obj.options[obj.selectedIndex].value.split(",");
  var newExtent = new OpenLayers.Bounds(newBounds[0], newBounds[1], newBounds[2], newBounds[3]);
  base.mergeNewParams({maxExtent: newExtent});
  map.zoomToExtent(newExtent);
}

function onPopupClose(evt) {
  select.unselectAll();
}

function onFeatureSelect(event) {
  var feature = event.feature;
  // Since KML is user-generated, do naive protection against Javascript.
  var content = "<h2>"+feature.attributes.name + "</h2>" + feature.attributes.description;
  if (content.search("<script") != -1) {
    content = "Content contained Javascript! Escaped content below.<br />" + content.replace(/</g, "&lt;");
  }
  popup = new OpenLayers.Popup.FramedCloud("chicken",
                       feature.geometry.getBounds().getCenterLonLat(),
                       new OpenLayers.Size(100,100),
                       content, null, true, onPopupClose);
  feature.popup = popup;
  map.addPopup(popup);
}

function onFeatureUnselect(event) {
  var feature = event.feature;
  if(feature.popup) {
    map.removePopup(feature.popup);
    feature.popup.destroy();
    delete feature.popup;
  }
}