geocode cadastral function from ESmisc

R/cadastral_references-data.R

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+#' Cadastral references test data
+#'
+#' Randomly selected data from catastro to test geocode_cadastral function
+#'
+#' @docType data
+#'
+#' @usage data(cadastral_references)
+#'
+#' @format A data frame.
+#'
+#' @keywords datasets
+#'
+#' @references Catastro. Ministerio de Hacienda y función pública.
+#' (\href{http://www.catastro.meh.es/}{Catastro})
+#'
+#' @source \href{http://www.catastro.meh.es/}{Sede Electrónica del Catastro}
+#'
+#' @examples
+#' ## source is cadastral reference number ##
+#'
+#' geocode_cadastral("0636105UF3403N", parse_files = FALSE)
+#'
+#' ## Use lapply to geocode cadastral references from dataframe columns.
+#'
+#' cadastral_references$new <- lapply(cadastral_references$cadref1, geocode_cadastral)
+#'
+#' ## separate previously generated "new" data into columns usign tidyr
+#'
+#' library(tidyr)
+#' separate(cadastral_references, new, into = c('longitude','latitude'), sep = "," )
+#'
+#' ## source is folder. A loop is needed to process each kml file ##
+#'
+#' \dontrun{
+#' files <- list.files("folder", full.names = T)
+#'
+#' for (f in files) {
+#'  coords <- geocode_cadastral(f, parse_files = TRUE)
+#'  d <- as.data.frame(rbind(d , as.data.frame(coords, stringsAsFactors = F )))
+#' }
+#'
+#'# separate lat/lon into columns if you prefer using tidyr
+#' d <- tidyr::separate(coords, into = c("longitude","latitude"), sep = "," )
+#'}
+"cadastral_references"

R/geocode_cadastral.R

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+#' geocode by longitude and latitude from cadastral references.
+#'
+#' Get longitude/latitude from valid cadastral ref. or kml files from catastro.
+#'
+#' @keywords geocoding, latitude, longitude, cadastre, cadastral reference.
+#' @param x A valid spanish cadastral reference.
+#' @param parse_files bool. Default to FALSE. Set TRUE if source are KML files.
+#' @return A string for longitude/latitude if found. NA if not found.
+#' @section Warning: You may be banned if many requests in short time are made.
+#' @export
+#' @examples
+#' ## source is cadastral reference number ##
+#' \dontrun{
+#' # geocode_cadastral("0636105UF3403N", parse_files = FALSE)
+#'
+#' ##"36.5209422288168,-4.89298751473745"
+#'
+#' ## Use lapply to geocode cadastral references from dataframe columns.
+#'
+#' cadastral_references$new <- lapply(cadastral_references$cadref1, geocode_cadastral)
+#'
+#' ## separate previously generated "new" data into columns usign tidyr
+#' 
+#' # library(tidyr)
+#' # separate(cadastral_references, new, into = c('longitude','latitude'), sep = "," )
+#'
+#' ## source is folder. A loop is needed to process each kml file ##
+#'
+#' # files <- list.files("folder", full.names = T)
+#'
+#' # for (f in files) {
+#' #  coords <- geocode_cadastral(f, parse_files = TRUE)
+#' # d <- as.data.frame(rbind(d , as.data.frame(coords, stringsAsFactors = F )))
+#' # }
+#'
+#'# separate lat/lon into columns if you prefer using tidyr
+#' # d <- tidyr::separate(coords, into = c("longitude","latitude"), sep = "," )
+#'}
+
+utils::globalVariables(".")
+
+geocode_cadastral <- function(x, parse_files) {
+
+  if (missing(parse_files)) {
+    parse_files <- FALSE
+  }
+
+  if (!requireNamespace("magrittr", quietly = TRUE)) {
+    stop("magrittr needed for this function to work. Please install it.",
+         call. = FALSE)
+  }
+
+  if (!requireNamespace("xml2", quietly = TRUE)) {
+    stop("xml2 needed for this function to work. Please install it.",
+         call. = FALSE)
+  }
+
+
+  if (parse_files) {
+
+    con <- file(x, "rb")
+
+  } else {
+
+    con <-
+      paste0(
+        "http://ovc.catastro.meh.es/Cartografia/WMS/BuscarParcelaGoogle.aspx?RefCat=",
+        x
+      )
+    Sys.sleep(2)
+
+  }
+
+  try(
+    coords <- xml2::read_xml(con) %>%
+    sub("kml xmlns", "kml xmlns:X", .) %>%
+    xml2::as_xml_document() %>%
+    xml2::xml_find_all("//Point/coordinates") %>%
+    xml2::xml_text() %>%
+    gsub('.{2}$', '', .),
+    silent = TRUE)
+
+  if (length(coords) == 0) coords <- NA
+
+  if (parse_files) close(con)
+
+  return(coords)
+
+}
+