R/GMLConventionalUnit.R

In eblondel/geometa: Tools for Reading and Writing ISO/OGC Geographic Metadata

#' GMLConventionalUnit
#'
#' @docType class
#' @importFrom R6 R6Class
#' @export
#' @keywords ISO GML conventional unit definition
#' @return Object of \code{\link{R6Class}} for modelling an GML derived unit
#' @format \code{\link{R6Class}} object.
#' 
#' @examples
#'    gml <- GMLConventionalUnit$new()
#'    gml$setDescriptionReference("someref")
#'    gml$setIdentifier("identifier", "codespace")
#'    gml$addName("name1", "codespace")
#'    gml$addName("name2", "codespace")
#'    gml$setQuantityTypeReference("someref")
#'    gml$setCatalogSymbol("symbol")
#'    gml$addDerivationUnitTerm("uomId", 2L)
#'    gml$setConversionToPreferredUnit("uomId", 2L)
#' 
#' @references 
#'   ISO 19136:2007 Geographic Information -- Geographic Markup Language.
#'   http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=32554 
#'   
#'   OGC Geography Markup Language. http://www.opengeospatial.org/standards/gml
#' 
#' @author Emmanuel Blondel <emmanuel.blondel1@@gmail.com>
#'
GMLConventionalUnit <- R6Class("GMLConventionalUnit",
  inherit = GMLUnitDefinition,
  private = list(
    xmlElement = "ConventionalUnit",
    xmlNamespacePrefix = "GML"
  ),
  public = list(
    #'@field conversionToPreferredUnit conversionToPreferredUnit [1..1]: character/integer
    conversionToPreferredUnit = NULL,
    #'@field roughConversionToPreferredUnit roughConversionToPreferredUnit [1..1]: character/integer
    roughConversionToPreferredUnit = NULL,
    #'@field derivationUnitTerm derivationUnitTerm [1..*]: character
    derivationUnitTerm = NULL,
    
    #'@description Initializes object
    #'@param xml object of class \link{XMLInternalNode-class}
    #'@param defaults default values
    #'@param id id
    initialize = function(xml = NULL, defaults = list(), id = NULL){
      super$initialize(xml, defaults)
      if(is.null(xml)){
        self$setId(id, addNS = TRUE)
      }
    },
    
    #'@description Adds a derivation unit term, made of a uom reference, and an exponent which
    #' can be negative/positive but not equal to zero.
    #'@param uom unit of measure reference
    #'@param exponent exponent
    #'@return \code{TRUE} if added, \code{FALSE otherwise}
    addDerivationUnitTerm = function(uom, exponent){
      if(exponent == 0L){
        stop("Exponent argument value cannot be equal to zero")
      }
      gmlElem <- GMLElement$create("derivationUnitTerm", attrs = list(uom = uom, exponent = exponent))
      return(self$addListElement("derivationUnitTerm", gmlElem))
    },
    
    #'@description Deletes a derivation unit term
    #'@param uom unit of measure reference
    #'@param exponent exponent
    #'@return \code{TRUE} if deleted, \code{FALSE otherwise}
    delDerivationUnitTerm = function(uom, exponent){
      if(exponent == 0L){
        stop("Exponent argument value cannot be equal to zero")
      }
      gmlElem <- GMLElement$create("derivationUnitTerm", attrs = list(uom = uom, exponent = exponent))
      return(self$delListElement("derivationUnitTerm", gmlElem))
    },
    
    #'@description Sets the conversion to preferred unit.
    #'@param uom unit of measure reference
    #'@param factor factor
    #'@param rough rough . Defaut is \code{FALSE}
    setConversionToPreferredUnit = function(uom, factor, rough = FALSE){
      elem <- ifelse(rough, "roughConversionToPreferredUnit", "conversionToPreferredUnit")
      gmlElem <- GMLElement$create(elem, attrs = list(uom = uom))
      gmlFactorElem <- GMLElement$create("factor", value = factor)
      gmlElem[["factor"]] <- gmlFactorElem
      self[[elem]] <- gmlElem
    }
  )
)