Question

I have been writing a light-weight framework to wrap the Windows API for personal projects and some fun. What I think is a good design method is that each class in the framework manages its own error information whenever something goes wrong. I have a simple error class like so:

class Error
{
public:

    struct ErrorData
    {
        DWORD       sysErrCode;
        tstring     sysErrStr;
        SYSTEMTIME  localTime;
        tstring     errMsg;
        tstring     funcCall;
        tstring     parentClass;
    };
    void getErrorData(ErrorData *pErrorData);
    Error(const tstring parentClass);
    void setErrorData(const tstring errMsg, const tstring funcCall, const bool getSysErr = false);

private:

    ErrorData errorData;
    void getSystemError(DWORD &sysErrCode, tstring &sysErrStr);
};

What I’m stuck on is how to incorporate this class into the other classes. Inheritance sounds wrong because a dialog class is not an Error class. Composition sounds better, a dialog class can have an Error class. But then I’m stuck writing a getter function for every class to retrieve the Error class’s information. Although that would only take a short time to write, there has got to be a better design method. I would rather not have to copy and paste those functions in every class either.

Any ideas would be appreciated!
Thank you.

Answer 1

Have you considered using exceptions and throwing your ErrorData class instead? That seems better than either inheritance or composition.

It almost looks like getSystemError should be a namespace free-function instead of a member (it looks like everything it needs is passed into its parameters).