WPCAPI.generateCellURL = function( parentID, title, tags, cellID ) {

return "/path/to/template/engine?cellId=" + cellID;

};

WPCAPI.generateCellURL = function( parentID, title, tags, cellID ) {

var params = '?'
+ "parentID=" + encodeURIComponent(parentID)
+ "&title=" + encodeURIComponent(title)
+ "&tags=" + encodeURIComponent(tags)
+ "&cellID=" + encodeURIComponent(cellID);

var request = new XMLHttpRequest();
request.open( "GET", "/path/to/generateURL/action" + params,true );
request.onreadystatechange = function() {

if( request.readyState == 4 ) {

var response = request.responseXML; // Format: <cell url="..."/>
var url = response ? response.getAttribute("url") : null;
WPCAPI.generateCellURL_Callback(url);

}

};
request.send(null);

return null;

};