OCAD Internet Map scripting

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Revision as of 10:26, 18 January 2019 by ANK (talk | contribs)
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OCAD Internet Maps can be customized by adapting the html file or with additional JavaScript code.

Zoom to Midway

In order to load the web map not in the smallest zoom level you can insert a command in the web map html file directly after the following line:

    zoomChanged(); 

Insert:

   map.zoomTo(map.numZoomLevels- Math.floor(map.numZoomLevels/2));

With this additional line the map is zoomed to midway of all available zoom levels during the startup instead of zoom level 0.

Hide/Show Layers

Layers can be shown or hidden with the layer command setVisibility. All Layers are exported in the order they are shown in the _poiLayers array.

Example:

	function ShowLayer() {
		_poiLayers[0].setVisibility(true);
	}

	function HideLayer() {
		_poiLayers[0].setVisibility(false);
	}

The Javascript functions can be called with an external link from the same page.

Jump to a Certain Point

In order to go to a certain location on the map the following function can be called.

	
        function JumpToPointOfInterest() {
		var point = new OpenLayers.LonLat(136733, 6667650);
		map.zoomTo(map.numZoomLevels-1);
		map.panTo(point);
	}

The variable map.numZoomLevels needs to be decreased by one to get the maximum zoom level.

Add Additional Vector Points for Locations

In order to achieve additional vector points this can be done with

	function ShowPointOfInterest() {
		var point1 = new OpenLayers.Geometry.Point(149667,6680327);
		var point2 = new OpenLayers.Geometry.Point(150386,6678682);
			
		var feature_point = new OpenLayers.Feature.Vector(point1, {},{fillOpacity : 0.4, pointRadius: 45, fillColor: "#ff0000" });
		var feature_point2 = new OpenLayers.Feature.Vector(point2, {},{pointRadius: 15, fillColor: "#ff0000"});
		
		highlight_layer.addFeatures([feature_point, feature_point2]);
	}

Therefore an additional layer needs to be introduced in the init script with the following lines:

    highlight_layer = new OpenLayers.Layer.Vector('Highlight Layer');
    map.addLayer(highlight_layer);

Please the two lines between the "addControl" commands and "XMLInitPois" command.

For the vector styling the options can be seen in the OpenLayers documentation: style options

Center Locations with Drop Down List

To center a location with a select list the following code can be introduced:

	function JumpToPoint(coords) {
		if (value = null) {
			exit;
		}
		var cord = coords.split(",");
		var point1 = new OpenLayers.LonLat(cord[0],cord[1]);
		map.zoomTo(map.numZoomLevels-1);
		map.panTo(point1);
  }

The code in the HTML file may looks like this:

<select id= "dropdown-select" onchange="JumpToPoint(this.value);">
	<option value="null">Select</option>
	<option value="134314,6668774">Location 1</option>
	<option value="149659,6679976">Location 2</option>
	<option value="140800,6668437">Location 3</option>
</select>