Question about HL7 errors

[adellieux]

Hi,

I have to implement an ACK message in which errors should be described.
In the case of HL7 errors, i have to fill an ERR / ErrorLocation instance, as well as the Hl7ErrorCode field (CodedWithException instance).
This ACK message is created after receiving another message from an external source.

I tried to generate an error in a sample HL7 message, for instance using a totally inexistent HL7 version.
When i deserialize the sample message, i get an exception, but no ErrorLocation.
After having this exception, how do you detect HL7 errors / collect HL7 error informations, like segment id, sequence, and other ErrorLocation properties ?
Do you have a validator, or something else i could use ?

About the CodedWithException instance (Hl7ErrorCode field in ERR segment), i have to fill the error code (using EnumToCode(CodeMessageErrorConditionCodes) ), and the text of the error.
Do you have the text of the errors using a function ?
For now, i will use a Dictionary or something equivalent with the error code enum and the different texts (taken from the CodeMessageErrorConditionCodes enum comments.
exemple :
ERR||MSH^1^12|203^Unsupported version^messageErrorCondition|E

Thanks for this library, and for your time ;-)

[adellieux]

I use the following, for now :

using ClearHl7.Codes.V260;

namespace Ecs.Document.Interop.HL7Builder.Messages.Ack.v260.Enums;

/// <summary>
/// HL7 Version 2 Table 0357 - Message Error Condition Codes.
/// </summary>
/// <remarks>https://www.hl7.org/fhir/v2/0357</remarks>
public static class CustomCodeMessageErrorCondition
{
    internal static Dictionary<CodeMessageErrorConditionCodes, string> CodeMessageErrorConditionStrings = new()
    {
        { CodeMessageErrorConditionCodes.MessageAccepted, "Message accepted" },
        { CodeMessageErrorConditionCodes.SegmentSequenceError, "SegmentSequenceError"},
        { CodeMessageErrorConditionCodes.RequiredFieldMissing, "Required field missing" },
        { CodeMessageErrorConditionCodes.DataTypeError, "Data type error" },
        { CodeMessageErrorConditionCodes.TableValueNotFound, "Table value not found" },
        { CodeMessageErrorConditionCodes.UnsupportedMessageType, "Unsupported message type" },
        { CodeMessageErrorConditionCodes.UnsupportedEventCode, "Unsupported event code" },
        { CodeMessageErrorConditionCodes.UnsupportedProcessingId, "Unsupported processing id" },
        { CodeMessageErrorConditionCodes.UnsupportedVersionId, "Unsupported version id" },
        { CodeMessageErrorConditionCodes.UnknownKeyIdentifier, "Unknown key identifier" },
        { CodeMessageErrorConditionCodes.DuplicateKeyIdentifier, "Duplicate key identifier" },
        { CodeMessageErrorConditionCodes.ApplicationRecordLocked, "Application record locked"},
        { CodeMessageErrorConditionCodes.ApplicationError, "Application error" },
    };

    /// <summary>
    /// Get the string associated to an enum value
    /// </summary>
    /// <param name="enumValue">MetaDmpMssItems enum value</param>
    /// <returns></returns>
    public static string? GetValue(CodeMessageErrorConditionCodes enumValue)
    {
        CodeMessageErrorConditionStrings.TryGetValue(enumValue, out string? value);
        return value;
    }
}

[davebronson]

Hi @adellieux

If you tried to deserialize a string representation of the Message that used an invalid HL7 version number, an ArgumentException should be thrown stating that it was Unable to determine the HL7 version [...]. Are you capturing this error? This is the first check done during that routine.

You can also call ClearHl7.Helpers.MessageHelper.DetectVersion() with an otherwise valid Message to manually run the HL7 version check routine. The method will return Hl7Version.None if the version is invalid.

Beyond this, ClearHl7 doesn't offer any HL7 validators outside of some basic checks that are done during deserialization. Message validation is a whole other beast to tackle. Maybe in a future version?

[adellieux]

Hi,

yes, i get an ArgumentException.
i may have to use DetectVersion() when receiving ACK messages from the receiver, and will see that point real soon.
i got a meeting to clarify what is required when sending an ACK + ERR message.
it appears that a detailed ERR message is not required, so in the end i don't need such an advanced feature.
in my use case, all you already implemented is really complete and sufficient.
using your library is really helpful and allows me to easily apprehend the HL7 format and structure.

thank you so much, @davebronson