R/ini_parse2.R

In sckott/inir: Parser for .ini/.cfg Files

#' Parse a .ini or a .cfg file
#'
#' @export
#' @param path (character) A single file path to read from on initialize, or
#' to write to on \code{write}
#' @details
#' \strong{Methods}
#'   \describe{
#'     \item{\code{read()}}{
#'       Read a file
#'     }
#'     \item{\code{write(path)}}{
#'       Write a file
#'       - path: path to write the file to
#'     }
#'     \item{\code{get(x, fallback)}}{
#'       Get a section
#'       - x: section name to get
#'       - fallback: (character) fallback value if 'x' not found
#'     }
#'     \item{\code{sections()}}{
#'       Get all sections of a file
#'     }
#'   }
#' @usage NULL
#' @format NULL
#' @examples \dontrun{
#' # example file
#' gitfile <- system.file("examples", "gitconfig.ini", package = "inir")
#'
#' # instantiate new object with file path
#' (res <- ini(gitfile))
#'
#' # get file path
#' res$file
#'
#' # read file
#' res$read()
#'
#' # get section names
#' res$sections()
#'
#' # get contents of a single section
#' res$get("core")
#' ## or index to it via the "parsed" element
#' res$parsed$gitconfig.ini[['core']]
#'
#' # another example getting a section
#' res$get('remote "origin"')
#' res$parsed$gitconfig.ini[['remote "origin"']]
#'
#' # You can set a default value with the get() method
#' res$get("stuff") # returns NULL
#' res$get("stuff", "hello_world") # default value
#'
#' # write file
#' res$write(path = "myfile2.ini")
#' unlink("myfile2.ini")
#' }
ini <- function(path) {
  Ini$new(file = path)
}

Ini <- R6::R6Class("Ini",
   portable = FALSE,
   public = list(
     file = NA,
     parsed = NA,

     initialize = function(file) {
       self$file <- file
     },

     print = function() {
       cat(paste0("<<ini config file>> ", basename(self$file), ".\n"))
     },

     read = function() {
       self$parsed <- ini_parse(self$file)
       self$parsed
     },

     sections = function() {
       names(self$parsed[[1]])
     },

     get = function(x, fallback) {
       tmp <- self$parsed[[1]][[x]]
       if (is.null(tmp)) {
         if (missing(fallback)) NULL else fallback
       } else {
         tmp
       }
     },

     write = function(path) {
       ini_write(self$parsed[[1]], path)
     }
   )
)