/**
* Directs a chart request to a ChartMediator.<br>
* Referring to a given configuration (id), it directs a request for a chart to a ChartMediator
* and returns the result.
*
* @param json String path to a .json file where request information are stored
* @return a json-object which contains all information about the requested chart
* @see ChartMediator
*/
public JSONObject computeChart(JSONObject json) {
if (json == null) {
throw new IllegalArgumentException();
}
// checks whether a request is allowed
if (!isInitialized()) {
Printer.pproblem("Configurations & mediators not initalized!");
Printer.print("-> Chart creation not possible!");
return null;
}
if (!(tablesAreCreated())) {
Printer.pproblem("Tables not created. Request not possible");
return null;
}
// direct request and hopefully receive a JSON object
JSONObject chart = chartMedi.computeChart(json);
if (chart == null) {
Printer.pfail("Computing chart.");
return null;
} else {
Printer.psuccess("Computing chart.");
}
return chart;
}
