What is PromptOptions.Validations

Question

In BotFramework V4 you can validate user inputs using your own validator function:

dialogs.Add(new TextPrompt("textPrompt", TextPromptValidatorAsync));

But there is also a Validations Property in PromptOptions class.

return await step.PromptAsync(
    TextPrompt,
    new PromptOptions
    {
        Prompt = MessageFactory.Text("What is your name?"),
        Validations = ??
    },
    cancellationToken);

What is it for?

Answer 1

Validations are objects that can be used to validate the responses from users.

The sample here shows an example. Essentially in this sample, it is using an async Task:

public Task<bool> CustomPromptValidatorAsync(PromptValidatorContext<string> promptContext, CancellationToken cancellationToken)

This has the logic to actually check what is valid. Then this is passed in when adding the TextPrompt dialog:

    _dialogs.Add(new TextPrompt("name", CustomPromptValidatorAsync));

The Validations property is how you can access that object.