WIP/check_spatype_method.R

In IREA-CNR-MI/sprawl: sprawl: Spatial Processing (in) R: Advanced Workflows Library

#' @title check_spatype
#' @description accessory function to check if an object passed to the function corresponds to
#' a `*Spatial` Object, a `sf` object, a R `raster` object, a file corresponding to a vector,
#' or a file corresponding to a raster
#' @param object either a `R` object or a `character` string pointing to a vector or raster layer
#' @return character vector equal to *spobject*, *sfobject*, *rastobject*, *vectfile* or *rastfile*
#'
#' @export
#' @importFrom gdalUtils ogrinfo gdalinfo
#' @examples \dontrun{
#' library(sprawl.data)
#' # input is a raster file
#' check_spatype(system.file("extdata","testrast.tif", package = "sprawl.data"))
#'
#' # input is a shapefile
#' shp_file <- system.file("extdata","lc_polys.shp", package = "sprawl.data")
#' check_spatype(shp_file)
#'
#' # input is a `sp` object
#' obj <- read_shape(shp_file, as_sp = TRUE)
#' check_spatype(obj)
#'
#' # input is a `sf` object
#' obj <- read_shape(shp_file)
#' check_spatype(obj)
#' }
#'
# check_spatype_met <- function(object) {
#   UseMethod("check_spatype", object)
# }
#
# check_spatype.default <- function(object) {
#   stop("none")
# }
#
#

if (!isGeneric("check_spatype")) {
  setGeneric("check_spatype", function(object)
    standardGeneric("check_spatype"))
}

setMethod("check_spatype",
          signature(object = "character"),
          function(object)
          {
            if (file.exists(object)) {
              vecttry <- suppressWarnings(try(gdalUtils::ogrinfo(object, al = TRUE, so = TRUE), silent = TRUE))
              if (is.null(attr(vecttry, "status"))) {
                "vectfile"
              } else {
                rastry <- suppressWarnings(try(gdalUtils::gdalinfo(object), silent = TRUE))
                if (is.null(attr(rastry, "status"))) {
                  "rastfile"
                } else {
                  "none"
                }
              }
            }
          }
)

setMethod("check_spatype",
          signature(object = "Raster"),
          function(object)
          {
            "rastobject"
          }
)

setMethod("check_spatype",
          signature(object = "sf"),
          function(object)
          {
            "sfobject"
          }
)

setMethod("check_spatype",
          signature(object = "Spatial"),
          function(object)
          {
            "spobject"
          }
)