Ejemplo de Javascript Ajax
Code
function createXMLHttpRequest() {
try { return new XMLHttpRequest(); } catch(e) {}
try { return new ActiveXObject(“Msxml2.XMLHTTP”); } catch (e) {}
alert(“XMLHttpRequest not supported”);
return null;
}
function reloadGPSData() {
var xhReq = createXMLHttpRequest();
xhReq.open(“GET”, “gps.php?mode=ajax”, true);
xhReq.onreadystatechange = function() {
if (xhReq.readyState != 4) { return; }
if ( xhReq.status >= 400 ) {
alert(xhReq.status + ‘: ‘ + xhReq.statusText);
return;
}
if ( xhReq.status == 0 ) {
alert(“Imposible conectar con el servidor.”);
return;
}
var json_text = xhReq.responseText;
var data = JSON.parse(json_text);
var latitude = data[0];
var longitude = data[1];
var satellites = data[2];
var error_desc = data[3];
document.getElementById(“longitude”).value = longitude;
document.getElementById(“latitude”).value = latitude;
document.getElementById(“satellites”).value = satellites;
document.getElementById(“error_desc”).innerHTML = error_desc;
setTimeout(‘reloadGPSData()’,1000);
}
xhReq.send(null);
}