Drawing polygons with WKT - XML file using OpenLayers - mysql

Question

I have this XML file created with PHP and Mysql:
How can I use this to draw all the polygons using OpenLayers? I did some research and found examples with WKT, but in those examples they used just one polygon:
var feature = format.readFeature(
'POLYGON((10.689697265625 -25.0927734375, 34.595947265625 ' +
'-20.1708984375, 38.814697265625 -35.6396484375, 13.502197265625 ' +
'-39.1552734375, 10.689697265625 -25.0927734375))');
I want to draw all the polygons to create a thematic map based on the "Area" data.

Answer 1

Just parse your XML and iterate over the marker tags. Something like this:
var xml = new OpenLayers.Format.XML(),
wkt = new OpenLayers.Format.WKT(),
vectorLayer = new OpenLayers.Layer.Vector('features'),
doc, markers, i, feature;
OpenLayers.Request.GET({
url: "features.xml",
success: function(request) {
doc = xml.read(request.responseText);
markers = doc.documentElement.getElementsByTagName('marker');
for (i = 0; i < markers.length; i++) {
feature = wkt.read(markers[i].attributes.geometry.nodeValue);
vectorLayer.addFeatures([feature]);
}
}
});
Edit: If you are using OpenLayers 3, try the following:
var wkt = new ol.format.WKT(),
vectorLayer,
source,
features = [],
feature,
markers;
//make sure that jQuery is included
$.ajax('features.xml').then(function(response) {
var markers = response.getElementsByTagName('marker');
for (var i = 0; i < markers.length; i++) {
feature = wkt.readFeature(markers[i].attributes.geometry.nodeValue);
features.push(feature);
}
source = new ol.source.Vector({
features: features
});
vectorLayer = new ol.layer.Vector({
source: source
});
});