How to allow the user only if he/she type the “ivr” or “IVR” using Form Flow concept - botframework

Question

I am working on bot framework technology, in one of my current project I want to allow the user only if he/she type the ‘’ivr” or “IVR” otherwise it shows some feedback to the user.
For that I have wrote below lines of code, but this code shows some wrong output to the user. Even if the user enter ivr or IVR it shows feedback to the user for the first time, but from second time onwards its working correctly.
[Serializable]
class Customer
{
//Create Account Template
[Prompt("Please send any of these commands like **IVR** (or) **ivr**.")]
public string StartingWord;
public static IForm<Customer> BuildForm()
{
OnCompletionAsyncDelegate<Customer> accountStatus = async (context, state) =>
{
await Task.Delay(TimeSpan.FromSeconds(5));
await context.PostAsync("We are currently processing your account details. We will message you the status.");
};
var builder = new FormBuilder<Customer>();
return builder
//.Message("Welcome to the BankIVR bot! To start an conversation with this bot send **ivr** or **IVR** command.\r \n if you need help, send the **Help** command")
.Field(nameof(Customer.StartingWord), validate: async (state, response) =>
{
var result = new ValidateResult { IsValid = true, Value = response };
string str = (response as string);
if (str.ToLower() != "ivr")
{
result.Feedback = "I'm sorry. I didn't understand you.";
result.IsValid = false;
return result;
}
else if (str.ToLower() == "ivr")
{
result.IsValid = true;
return result;
}
else
{
return result;
}
})
.OnCompletion(accountStatus)
.Build();
}
};
Please tell me how to resolve this issue using Form Flow concept.
-Pradeep

Answer 1

Your code looks correct to me - I can only suggest you debug your code with a step-through debugger and see where the logic tests are failing.
That said, if it's not working for people in Turkey, it's because you shouldn't use .ToLower() for normalizing text, for example the .ToLower() method does not work for text that contains the Turkish dotless 'I' character: http://archives.miloush.net/michkap/archive/2004/12/02/273619.html
Also, your else case will never be hit because your two prior checks (!= and ==) cover every possible case (the C# compiler is currently not sophisticated enough to flag the else case as unreachable code).
The correct way to do a case-insensitive comparison is with String.Equals:
if( "ivr".Equals( str, StringComparison.InvariantCultureIgnoreCase ) ) {
result.IsValid = true;
return result;
}
else {
result.Feedback = "I'm sorry. I didn't understand you.";
result.IsValid = false;
}

Answer 2

Finally, I got the result with out any issue.
here is my updated code for to allow only the user enter "ivr or IVR" word, to start a form flow conversation with bot.
.Field(nameof(Customer.StartingWord), validate: async (state, response) =>
{
var result = new ValidateResult { IsValid = true, Value = response };
string str = (response as string);
if ("ivr".Equals(str, StringComparison.InvariantCultureIgnoreCase))
{
//result.IsValid = true;
//return result;
}
else
{
result.Feedback = "I'm sorry. I didn't understand you.";
result.IsValid = false;
//return result;
}
return result;
})
-Pradeep