How To Set OBX ObservationValue (RP) Value With Special Characters

[amzinyama]

Hi!
I'm trying to add a value to ObservationValue in the OBX segment. I have it working but have an issue. I have the code below:

public void CreateOBXSegment(HL7Request request)
        {
            var obx = _hl7Message.GetORDER().ORDER_DETAIL.AddOBSERVATION().OBX;

            obx.SetIDOBX.Value = request.OBXID;
            obx.ValueType.Value = request.OBXValueType;
            obx.ObservationIdentifier.Identifier.Value = request.OBXObservationIdentifier;

            // Set the observation value based on the value type
            IType observationValue = null;
            switch (request.OBXValueType)
            {
                case "ST": // String Data
                    observationValue = new ST(_hl7Message);
                    ((ST)observationValue).Value = request.OBXObservationValue;

                    break;
                case "NM": // Numeric
                    observationValue = new NM(_hl7Message);
                    ((NM)observationValue).Value = request.OBXObservationValue;

                    break;
                case "CE": // Coded Element
                    observationValue = new CE(_hl7Message);
                    ((CE)observationValue).Identifier.Value = request.OBXObservationValue;

                    break;
                case "RP": // Reference Pointer
                    observationValue = new RP(_hl7Message);
                    ((RP)observationValue).Pointer.Value = request.OBXObservationValue;

                    break;
                // Add more cases as needed for other data types
                default:
                    observationValue = new ST(_hl7Message);
                    ((ST)observationValue).Value = request.OBXObservationValue;

                    break;
            }
            obx.GetObservationValue(0).Data = observationValue;

            obx.ObservationResultStatus.Value = request.OBXObservationResultStatus;
        }

request.OBXObservationValue is a string
"http://192.168.1.4//Integrator.aspx?uname=ris&pwd=1234&StudyUID=1.2.3&AccNo=1234&StudyID=&ZFP=True&Branch="

but when I parse the IMessage object to write it to file the '&' character is being replaced with '\T' and results in the following output:

"http://192.168.1.4//Integrator.aspx?uname=ris\T\pwd=1234\T\StudyUID=\T\AccNo=1234\T\StudyID=\T\ZFP=True\T\Branch=".

What can I do to fix this? Or how can I unescape the IMessage before I write it to file.

[milkshakeuk]

Hi!
I'm trying to add a value to ObservationValue in the OBX segment. I have it working but have an issue. I have the code below:

public void CreateOBXSegment(HL7Request request)
        {
            var obx = _hl7Message.GetORDER().ORDER_DETAIL.AddOBSERVATION().OBX;

            obx.SetIDOBX.Value = request.OBXID;
            obx.ValueType.Value = request.OBXValueType;
            obx.ObservationIdentifier.Identifier.Value = request.OBXObservationIdentifier;

            // Set the observation value based on the value type
            IType observationValue = null;
            switch (request.OBXValueType)
            {
                case "ST": // String Data
                    observationValue = new ST(_hl7Message);
                    ((ST)observationValue).Value = request.OBXObservationValue;

                    break;
                case "NM": // Numeric
                    observationValue = new NM(_hl7Message);
                    ((NM)observationValue).Value = request.OBXObservationValue;

                    break;
                case "CE": // Coded Element
                    observationValue = new CE(_hl7Message);
                    ((CE)observationValue).Identifier.Value = request.OBXObservationValue;

                    break;
                case "RP": // Reference Pointer
                    observationValue = new RP(_hl7Message);
                    ((RP)observationValue).Pointer.Value = request.OBXObservationValue;

                    break;
                // Add more cases as needed for other data types
                default:
                    observationValue = new ST(_hl7Message);
                    ((ST)observationValue).Value = request.OBXObservationValue;

                    break;
            }
            obx.GetObservationValue(0).Data = observationValue;

            obx.ObservationResultStatus.Value = request.OBXObservationResultStatus;
        }

request.OBXObservationValue is a string
"http://192.168.1.4//Integrator.aspx?uname=ris&pwd=1234&StudyUID=1.2.3&AccNo=1234&StudyID=&ZFP=True&Branch="

but when I parse the IMessage object to write it to file the '&' character is being replaced with '\T' and results in the following output:

"http://192.168.1.4//Integrator.aspx?uname=ris\T\pwd=1234\T\StudyUID=\T\AccNo=1234\T\StudyID=\T\ZFP=True\T\Branch=".

What can I do to fix this? Or how can I unescape the IMessage before I write it to file.

Can you provide example code where you are writing to a file?

[amzinyama]

Hi. Sorry for the late reply. I'm writing the message object to file using the method below:

public override bool Send(string RefNo, IMessage msg)
{
    try
    {
        string path = outputDir + GetFileName(RefNo, msg);
        //using (StreamWriter sw = new StreamWriter(File.OpenWrite(path), System.Text.Encoding.ASCII))
        using (StreamWriter sw = new StreamWriter(File.OpenWrite(path)))
        {
            PipeParser parser = new PipeParser();

            string encodedMessage = parser.Encode(msg);

            sw.Write(encodedMessage);
            //sw.Write(parser.Encode(msg));
        }
    }
    catch (IOException)
    {
        return false;
    }

    return true;
}

[milkshakeuk]

@amzinyama what you are seeing in your file is normal, the encoder is escaping special characters, when the message is decoded again the escaping is unescaped again.

https://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=EHL72_escape_sequences

[amzinyama]

Hi... Thank you for the response. My apologise for the late response. I understand.