IValueRequest - null reference exception

[kwesterlage]

I am receiving a null reference exception when trying to access the "Available" property of IValueRequest, but only if the Request ID is "QuickPrompt".
What is the best way to work around this?

[BobRichards]

Please include a code snippet. I'm not sure what an "IValueRequest" object is.

[kwesterlage]

IValueRequest is in SoftPro.Documents.Client.Rendering

Code: Select all

public class TestPrompts : IPrompt<PromptEventArgs>
{
    public TestPrompts(){}
    public void Request(PromptEventArgs value)
    {        
        foreach (IRequest prompt in value.Requests)
        {
            var selectionReq = prompt as ISelectionRequest;
            if (selectionReq != null)
            {
                // logic for handling a selection request 
                selectionReq.Handled = true;
            }

            var valueReq = prompt as IValueRequest;
            if (valueReq != null)
            {
                // logic for handling a value request
                var availableValues = valueReq.Available; // When valueReq.ID == "QuickPrompt", this line throws a null reference exception
                valueReq.Handled = true;
            }
        }
    }
}

[BobRichards]

You need to know ahead of time the requirements of the document you are trying to render including the request IDs (IRequest.ID). You should not access the request unless the request corresponds to an ID you are expecting. The interface is designed to render documents when you know the appropriate responses.

Do you have a question regarding a specific one? If you are just looking to see what's there, a try/catch around the offending line sounds like a option - but not in production code!