Gets the signatures for any input columns that are possible to choose from as inputs. In a typical scenario they would be exposed either to the end user in the UI or through the api for an apiuser to select among. Once some are selected they can be used in SetInputs(VirtualColumnInputIdentifier, IEnumerable DataColumnSignature ) to set the inputs for a particular VirtualColumnInputIdentifier. Each output column is associated with an identifier and thus the set inputs in ConfigureColumnsCore(VirtualColumnsConfigurator).

protected VirtualColumnAvailableInputCollection AvailableInputs { get; }

protected VirtualColumnAvailableInputCollection AvailableInputs { get; }