R/get_xml_base_node.R

In SticsRFiles: Read and Modify 'STICS' Input/Output Files

#' @title Get an xml_document node (set of parameters) from a STICS xml node
#' file template
#' @param file_tag file tag among "usms","sols", "tec"
#' @param form_name formalism name
#' @param stics_version the STICS files version to use
#'
#'
#' @return An xml node of type "usm", "sol", "intervention"
#'
#' @examples
#' \dontrun{
#' get_xml_base_node("usms")
#'
#' get_xml_base_node("sols")
#'
#' # Formalism labels can be retrieved using
#' get_xml_base_node()$form_names$tec
#'
#' get_xml_base_node("tec", "irrigation")
#' }
#'
#' @keywords internal
#'
#' @noRd
#'
# TODO: under construction !!!!!!!!!!!!!!!!!
get_xml_base_node <- function(file_tag, form_name = NULL,
                              stics_version = "latest") {

  # check/get STICS version
  stics_version <- get_xml_stics_version(stics_version = stics_version)


  files_tags <- c("usms", "sols", "tec")
  node_names <- c("usm", "sol", "intervention")
  parent_nodes <- c("usms", "sols", "ta")
  formalism_tags <- list()
  formalism_tags$tec <- c("res", "till", "irr", "ferN", "spec")
  # , "cutJul", "cutTemp")
  formalism_tags$usms <- c()
  formalism_tags$sols <- c()

  formalism_names <- list()
  formalism_names$tec <- c(
    "supply of organic residus",
    "soil tillage",
    "irrigation",
    "fertilisation",
    "special techniques"
  ) # ,
  # "calendar in days",
  # "calendar in degree days")

  formalism_names$usms <- c()
  formalism_names$sols <- c()


  if (!nargs()) {
    return(list(
      files_tags = files_tags,
      node_names = node_names,
      parent = parent_nodes,
      form_tags = formalism_tags,
      form_names = formalism_names
    ))
  }



  # see if needed: plt -> cultivars ?

  file_idx <- files_tags %in% file_tag
  if (!any(file_idx)) {
    stop("unknown file type !")
  }

  node <- node_names[file_idx]

  in_formalism_name <- FALSE
  if (!base::is.null(form_name)) {
    in_formalism_name <- file_tag %in% names(formalism_names)
  }

  if (in_formalism_name && !form_name %in% formalism_names[[file_tag]]) {
    stop(paste0("unknown node for ", file_tag))
  }

  # Retrieving the formalism tag
  form_tag <-
    formalism_tags[[file_tag]][formalism_names[[file_tag]] %in% form_name]

  # Setting the right template name
  if (!in_formalism_name) {
    file_name <- paste0("one_", file_tag, ".xml")
  } else {
    file_name <- paste0("one_", form_tag, "_", file_tag, ".xml")
  }

  # Template path in the library
  xml_file <- file.path(
    get_examples_path(file_type = "xml_tmpl", stics_version = stics_version),
    file_name)

  # Loading the template into an xmDocument
  xml_doc <- xmldocument(xml_file)

  # Convert it into a string
  base_node_txt <- XML::saveXML(get_nodes(xml_doc, paste0("//", node))[[1]])

  # TODO: see if useful to call xmlClone or not ?
  # Getting the node from a node set
  new_node <- XML::getNodeSet(
    XML::xmlParse(base_node_txt),
    paste0("//", node))[[1]]

  delete(xml_doc)

  return(new_node)
}