What to Return? Error String, Bool with Error String Out, or Void with Exception
- by Ranger Pretzel
I spend most of my time in C# and am trying to figure out which is the best practice for handling an exception and cleanly return an error message from a called method back to the calling method.
For example, here is some ActiveDirectory authentication code. Please imagine this Method as part of a Class (and not just a standalone function.)
bool IsUserAuthenticated(string domain, string user, string pass, out errStr)
{
bool authentic = false;
try
{
// Instantiate Directory Entry object
DirectoryEntry entry = new DirectoryEntry("LDAP://" + domain, user, pass);
// Force connection over network to authenticate
object nativeObject = entry.NativeObject;
// No exception thrown? We must be good, then.
authentic = true;
}
catch (Exception e) { errStr = e.Message().ToString(); }
return authentic;
}
The advantages of doing it this way are a clear YES or NO that you can embed right in your If-Then-Else statement. The downside is that it also requires the person using the method to supply a string to get the Error back (if any.)
I guess I could overload this method with the same parameters minus the "out errStr", but ignoring the error seems like a bad idea since there can be many reasons for such a failure...
Alternatively, I could write a method that returns an Error String (instead of using "out errStr") in which a returned empty string means that the user authenticated fine.
string AuthenticateUser(string domain, string user, string pass)
{
string errStr = "";
try
{
// Instantiate Directory Entry object
DirectoryEntry entry = new DirectoryEntry("LDAP://" + domain, user, pass);
// Force connection over network to authenticate
object nativeObject = entry.NativeObject;
}
catch (Exception e) { errStr = e.Message().ToString(); }
return errStr;
}
But this seems like a "weak" way of doing things.
Or should I just make my method "void" and just not handle the exception so that it gets passed back to the calling function?
void AuthenticateUser(string domain, string user, string pass)
{
// Instantiate Directory Entry object
DirectoryEntry entry = new DirectoryEntry("LDAP://" + domain, user, pass);
// Force connection over network to authenticate
object nativeObject = entry.NativeObject;
}
This seems the most sane to me (for some reason). Yet at the same time, the only real advantage of wrapping those 2 lines over just typing those 2 lines everywhere I need to authenticate is that I don't need to include the "LDAP://" string. The downside with this way of doing it is that the user has to put this method in a try-catch block.
Thoughts?
Is there another way of doing this that I'm not thinking of?
