R/whisker_get_all.R

In decisionpatterns/whisker.tools: Extensions and Enhancements to the 'whisker' package

#' Get template values from the call stack
#'
#' Introspect template and get values from their first appearance on the call
#' stack.
#'
#' @param template character; a whisker template
#'
#' @param ... additional arguments passed to \code{\link[base]{get}}
#'
#' \code{whisker_get_all} searches the call stack to find the variables in a
#' whisker template.
#'
#' @return
#'   list containing the names and values from the template. If a value is not 
#'   found, \code{NA} is returned.
#'
#' @seealso
#'   \code{\link[base]{get}} \cr
#'   \code{\link{whisker_names}} \cr
#'
#' @examples
#'
#'   a=1; z=26
#'
#'   tmpl = "A is rank {{a}}; z is rank {{z}}; {{w}}"
#'   whisker_get_all( tmpl )
#'
#'   # In function:
#'   f <- function( template ) whisker_get_all( template )
#'   f(tmpl)
#'
#' @export


whisker_get_all <- function(template, ...) {

  nms <- whisker_names(template)

  li <- list()
  for( nm in nms ) {
    li[[nm]] <- tryCatch( 
        get(nm, ..., inherits = TRUE )
      , error = function(...) { 
          warning( "whisker_get_all - ", nm, " not found", immediate. = TRUE, call. = FALSE )
          return(NA)
        }  
    )
  }

  return(li)

}