\name{funArg-class}
\docType{class}
\alias{funArg-class}
\alias{funArg}
\alias{argDefault}
\alias{argLocation}
\alias{argName}
\alias{argRequired}
\alias{argType}
\alias{argWidgetType}
\alias{argDefault,funArg-method}
\alias{argLocation,funArg-method}
\alias{argName,funArg-method}
\alias{argRequired,funArg-method}
\alias{argType,funArg-method}
\alias{argWidgetType,funArg-method}

\title{Class "funArg": A Class To Represent A Function Argument}
\description{
  This class is used by the \code{widgetInvoke} to represent the
  necessary information for creation of widgets for a function
  argument.  Each argument for a function maps to an object of class
  \code{funArg}, and stored as a list with the others in the
  \code{funArgList} slot of the appropriate \code{wFun} object.
}
\section{Objects from the Class}{
Objects can be created by calls of the form \code{new("funArg", ...)}.
}
\section{Slots}{
  \describe{
    \item{\code{argName}:}{Object of class \code{"character"}: The name
      of the argument}
    \item{\code{argDefault}:}{Object of class \code{"character"}: The
      default value of the argument.}
    \item{\code{argType}:}{Object of class \code{"character"}: The type
      of the argument (e.g. numeric, character, logical)}
    \item{\code{argLocation}:}{Object of class \code{"character"}: Which
    pane of the widget notebook to display this argument.}
    \item{\code{argWidgetType}:}{Object of class \code{"character"}:
      What type of widget to use in displaying this argument.}
    \item{\code{argRequired}:}{Object of class \code{"logical"}: Whether
    or not this argument is required to have a value for function
    evaluation.}
  }
}
\section{Methods}{
  \describe{
    \item{argDefault}{\code{signature(object = "funArg")}: Retrieves the
    argDefault slot.}
    \item{argLocation}{\code{signature(object = "funArg")}: Retrieves
      the argLocation slot.}
    \item{argName}{\code{signature(object = "funArg")}: Retrieves the
      argName slot.}
    \item{argRequired}{\code{signature(object = "funArg")}: Retrieves
      the argRequired slot.}
    \item{argType}{\code{signature(object = "funArg")}: Retrieves the
      argType slot.}
    \item{argWidgetType}{\code{signature(object = "funArg")}: Retrieves
      the argWidgetType slot}
  }
}
\details{
  The \code{argType} slot can specify a particular type, or use the
  string \code{ANY} to allow this argument to be untyped.  When using
  the \code{fun2wFun} function, the default for a \code{funArg} object
  is that if there is no \code{argDefault} specified by the function,
  there will be no \code{argType}.  Likewise, if there is an
  \code{argDefault}, the \code{argType} will be of the same type.
}
\author{Jeff Gentry}
\seealso{\code{\link{createWF}}, \code{\link{widgetInvoke}},
  \code{\link{wFun}}}
\examples{
        z <- readWIxml(system.file("wFun-example", "apropos.xml",
                  package="widgetInvoke"))
        a <- funArgList(z)[[1]]
        argRequired(a)
        argName(a)
        argType(a)
}
\keyword{classes}