/// <summary>
/// Processes incoming requests of request_type 'read' or 'write'
/// </summary>
/// <param name="request"></param>
/// <returns>Same as incoming request but with fields for 'values' (in case of read request) and / or 'message' (in case of error) filled.</returns>
public TCRequest ProcessTCRequest(TCRequest request)
{
var hash = request.GetHashCode();
string currentVar = "";
try
{
if (request.names?.Length != request.types?.Length ||
request.names?.Length == 0 ||
request.request_type == null ||
(request.request_type != "read" && request.request_type != "write") ||
(request.request_type == "write" && request.values?.Length != request.names?.Length))
{
request.message = "Invalid request! Length of names and types must be equal and larger than zero. Request type must be either 'read' or 'write'. If request_type is 'write' values must be supplied.";
Send_TcClient_EventHandling(DateTime.Now, LogTextCategory.Error, request.message, Verbosity.Important);
return(request);
}
Send_TcClient_EventHandling(DateTime.Now, LogTextCategory.Incoming, string.Format("Received ADS {0} request for {1} items (hash: {2})", request.request_type, request.names.Length, hash));
//read request
if (request.request_type == "read")
{
request.values = new object[request.names.Length];
for (int i = 0; i < request.names.Length; i++)
{
currentVar = request.names[i];
if (!request.types[i].EndsWith("]") || request.types[i].StartsWith("string"))
{
request.values[i] = ReadItem(request.names[i], request.types[i]);
}
else
{
var length = int.Parse(request.types[i].Split('[')[1].Split(']')[0]);
request.values[i] = ReadArray(request.names[i], request.types[i], length);
}
}
}
//write request
else
{
for (int i = 0; i < request.names.Length; i++)
{
currentVar = request.names[i];
if (!request.types[i].EndsWith("]") || request.types[i].StartsWith("string"))
{
WriteItem(request.names[i], request.types[i], request.values[i]);
}
else
{
var length = int.Parse(request.types[i].Split('[')[1].Split(']')[0]);
var arr = (request.values[i] as Newtonsoft.Json.Linq.JArray).ToObject <object[]>();
if (arr.Length != length)
{
throw new Exception(
string.Format(
"Write request for {0}: Array length in 'values' ({1}) doesn't match the indicated array length in 'types' property ({2}). " +
"Make sure they are the same\nFor example if your item is an integer array of length three ('values' = [[2, 4, 1]]) " +
"make sure to indicate the correct length in 'types' = ['int[3]']", request.names[i], arr.Length, length));
}
WriteArray(request.names[i], request.types[i], arr);
}
}
}
Send_TcClient_EventHandling(DateTime.Now, LogTextCategory.Outgoing, string.Format("Responded to ADS {0} request for {1} items (hash: {2})", request.request_type, request.names.Length, hash));
}
catch (Exception e)
{
request.message = string.Format("Error at variable: '{0}'. --- Error Message: {1}. --- Please refer to TwinCATAdsServer log for more info.", currentVar, e.Message);
Send_TcClient_EventHandling(DateTime.Now, LogTextCategory.Error,
string.Format("Exception occured during processing of request:{0}Variable: {1}{0}Request hash: {2}{0}Exception: {3}", Logging.NewLineTab, currentVar, hash, e.ToString()));
}
return(request);
}
public async Task HandleIncomingRequests()
{
// While a user hasn't visited the `shutdown` url, keep on handling requests
while (Running)
{
// Will wait here until we hear from a connection
HttpListenerContext ctx = await listener.GetContextAsync();
LogArgs.When = DateTime.Now;
HttpListenerRequest req = ctx.Request;
HttpListenerResponse resp = ctx.Response;
resp.ContentType = "application/json";
resp.ContentEncoding = Encoding.UTF8;
try
{
//check if this is a shutdown request
if (req.Url.AbsolutePath == "/btn_shutdown")
{
Running = false;
byte[] resBytes = Encoding.UTF8.GetBytes("bye");
resp.OutputStream.Write(resBytes, 0, resBytes.Length);
break;
}
//turn http request into tcsrequest object
var tcRequest = JsonConvert.DeserializeObject <TCRequest>(req.Url.LocalPath.Remove(0, 1));
var hash = tcRequest.GetHashCode();
//notify user
LogArgs.Message = string.Format("Received {0} request from {1}. (hash: {2})", req.HttpMethod, req.RemoteEndPoint, hash);
LogArgs.Verbosity = Verbosity.Important;
LogArgs.Category = LogTextCategory.Incoming;
Logging.SendMessage(LogArgs);
//actually process the request using TcIOClient
var res = TcIOClient.ProcessTCRequest(tcRequest);
LogArgs.When = DateTime.Now;
var js = JsonConvert.SerializeObject(res);
byte[] data = Encoding.UTF8.GetBytes(js);
//formulate response
resp.ContentLength64 = data.LongLength;
await resp.OutputStream.WriteAsync(data, 0, data.Length);
LogArgs.Message = string.Format("Responded with data of size {0} to {1} request. (hash: {2})", resp.ContentLength64, req.HttpMethod, hash);
LogArgs.Category = LogTextCategory.Outgoing;
LogArgs.Verbosity = Verbosity.Important;
Logging.SendMessage(LogArgs);
resp.Close();
}
catch (Exception e)
{
var tcNull = new TCRequest();
tcNull.message = string.Format("Error in Http Server: {0} - Please refer to TwinCATHttpServer log for more information.", e.Message);
LogArgs.Message = string.Format("Error in Http Server:{0}{1}{0}{2}", Logging.NewLineTab, e.Message, e.ToString());
LogArgs.Category = LogTextCategory.Error;
LogArgs.Verbosity = Verbosity.Important;
Logging.SendMessage(LogArgs);
var js = JsonConvert.SerializeObject(tcNull);
byte[] data = Encoding.UTF8.GetBytes(js);
resp.ContentLength64 = data.LongLength;
await resp.OutputStream.WriteAsync(data, 0, data.Length);
resp.Close();
}
}
}
