private void SendResponse(MsgMeas.GetObservationResponse responseObj)
{
// Serialising the object
byte[] responseXml = responseObj.ToXmlBytes();
// Sending the response to the client...
// In real life, you will have to consider where to send.
// This depends on the protocol and network structure.
throw new NotImplementedException();
}
public void Get()
{
// Creating a request object
var requestObj = new MsgMeas.GetObservationRequest();
// Setting the conditions of the request
requestObj.FeaturesOfInterest.Add("myplant/myprocess/mytemperature");
// Adding a data record; use this to whatever additional parameters you need.
// This naturally depends on the server.
var extensionObj = new MsgMeas.Item_DataRecord()
{
{ "parameter_x", new MsgMeas.Item_Count(3) }
};
requestObj.Items.Add(extensionObj);
// Adding a temporal filter: retrieve all observation after given time
var tempFilter1 = new MsgMeas.TemporalFilter(
MsgMeas.TemporalFilter.ValueReferenceType.PhenomenonTime,
MsgMeas.TemporalFilter.OperatorType.After,
new MsgMeas.Item_TimeInstant(DateTime.Parse("2018-05-18T08:05:44Z").ToUniversalTime())
);
requestObj.TemporalFilters.Add(tempFilter1);
// Serialising the request object
byte[] requestXml = requestObj.ToXmlBytes();
// Sending the requestXml to the server and waiting for a response...
SendRequest(requestXml);
byte[] responseXml = WaitForResponse();
// Processing the response
MsgMeas.GetObservationResponse responseObj;
try
{
responseObj = new MsgMeas.GetObservationResponse(responseXml);
}
catch (MsgMeas.Neutral.InvalidMessageException e)
{
throw new InvalidOperationException("Failed to read server response: " + e.Message, e);
}
if (responseObj.RequestResult != MsgMeas.RequestResultType.Ok)
{
throw new InvalidOperationException("Unexpected response from server");
}
foreach (var obs in responseObj.Observations)
{
// Processing the observations...
// ...
}
}
public void Serve()
{
while (true)
{
// Waiting for a request to come from the network
byte[] requestXml = WaitForRequest();
MsgMeas.GetObservationRequest requestObj;
try
{
requestObj = new MsgMeas.GetObservationRequest(requestXml);
}
catch (MsgMeas.Neutral.InvalidMessageException e)
{
Console.WriteLine("Failed to read request: " + e.Message);
continue;
}
// Assuming a certain feature of interest
if (!requestObj.FeaturesOfInterest.Contains("myplant/myprocess/mytemperature"))
{
// Error!
var errorResponse = new MsgMeas.GetObservationResponse()
{
RequestResult = MsgMeas.RequestResultType.NotFound
};
SendResponse(errorResponse);
continue;
}
// Looking at the temporal filter received from the client
var temporalFilter = requestObj.TemporalFilters[0];
// Retrieving data (e.g., from a database). Filtering with the temporal filter.
// ...
// Building a response object
var responseObj = new MsgMeas.GetObservationResponse()
{
RequestResult = MsgMeas.RequestResultType.Ok
};
// Setting observation data. Suppose these have been retrieved from a database, for instance.
var observation1 = new MsgMeas.Observation(new MsgMeas.Item_Measurement("s", 2.2));
var observation2 = new MsgMeas.Observation(new MsgMeas.Item_Measurement("s", 2.4));
responseObj.Observations.Add(observation1);
responseObj.Observations.Add(observation2);
// Sending the response
SendResponse(responseObj);
}
}
