R/methods.R

In metamer: Create Data with Identical Statistics

#' @export
as.data.frame.metamer_list <- function(x, ..., n = length(x)) {
  return(x$as.data.frame())
}



# Dynamically exported. From:
# https://community.rstudio.com/t/write-s3-methods-for-generics-from-other-packages-without-importing-that-package/8884/4
fortify.metamer_list <- function(model, data, ..., n = 6) {
  as.data.frame(model, ..., n = n)
}

as.data.table.metamer_list <- function(x, ..., n = length(x)) {
  if (!requireNamespace("data.table", quietly = TRUE)) {
    stop("data.table is not installed. Install it with `install.packages(\"data.table\")`.")
  }
  return(x$as.data.table())
}


# nocov start
.onLoad <- function(...) {
  register_s3_method("ggplot2", "fortify", "metamer_list")
  register_s3_method("data.table", "as.data.table", "metamer_list")
  invisible()
}

register_s3_method <- function(pkg, generic, class, fun = NULL) {
  stopifnot(is.character(pkg), length(pkg) == 1)
  stopifnot(is.character(generic), length(generic) == 1)
  stopifnot(is.character(class), length(class) == 1)

  if (is.null(fun)) {
    fun <- get(paste0(generic, ".", class), envir = parent.frame())
  } else {
    stopifnot(is.function(fun))
  }

  if (pkg %in% loadedNamespaces()) {
    registerS3method(generic, class, fun, envir = asNamespace(pkg))
  }

  # Always register hook in case package is later unloaded & reloaded
  setHook(
    packageEvent(pkg, "onLoad"),
    function(...) {
      registerS3method(generic, class, fun, envir = asNamespace(pkg))
    }
  )
}
# nocov end