Defines functions exportCSV

Documented in exportCSV

#' @title exportCSV: Export SQL views to .csv
#' @description This function exports NETN_Forest database views either to individual .csv files, or as a zip file
#' with the database name (NETN_Forest), and the date it was zipped. The exported .csv or .zip files can then be imported
#' via importCSV(). This function is primarily for internal use to create flat files that users can import to run
#' functions in this package without having a connection to the database server. This is particularly useful for external
#' users who don't have access to NPS servers.
#' @param path Quoted path to save files to. If not specified, will save to working directory.
#' @param zip Logical. If TRUE, exports a zip file. If FALSE (Default), exports individual csvs.
#' @return NETN database views exported to specified path
#' @examples
#' library(forestNETN)
#' importData()
#' # Export csvs to working directory
#' exportCSV()
#' # Export a zip to the path specified
#' exportCSV(path = "C:/Forest_Health/exports/NETN", zip = TRUE)
#' # Export views as .csvs to specified path
#' exportCSV(path = "C:/Forest_Health/exports/NETN")
#' @export

exportCSV<- function(path = NA, zip = FALSE){

  # Check that suggested package required for this function are installed
  if(!requireNamespace("zip", quietly = TRUE) & zip == TRUE){
    stop("Package 'zip' needed to export to zip file. Please install it.", call. = FALSE)

  options(scipen = 100) # For TSNs

  # Make sure all the views are loaded. If anything is missing, function stops.
  view_list <- c("COMN_AdditionalSpecies", "COMN_CWD", "COMN_EventObservers", "COMN_Events",
                 "COMN_MicroplotShrubs", "COMN_Plots", "COMN_QuadCharacter",
                 "COMN_SoilHeader", "COMN_SoilSample", "COMN_SoilLab",
                 "COMN_StandDisturbances", "COMN_StandForestFloor", "COMN_StandPlantCoverStrata",
                 "COMN_StandSlopes", "COMN_StandTreeHeights", "COMN_Taxa", "COMN_TreesByEvent",
                 "COMN_TreesConditions", "COMN_TreesFoliageCond", "COMN_TreesVine",
                 "NETN_MicroplotSaplings", "NETN_MicroplotSaplingsCount",
                 "NETN_MicroplotSeedlings", "NETN_QuadSpecies", "NETN_StandInfoPhotos")

  files <- if(exists("VIEWS_NETN")){ls(envir = VIEWS_NETN)} else {ls()}

  missing <- setdiff(view_list, files)

  if(length(missing) > 0 & length(missing) < length(view_list)){
    stop(paste0("Missing the following views: ", paste0(missing, collapse = ", ")))
  } else if (length(missing) == length(view_list)){
    stop("Views were not detected in your workspace. Please import the data first.")}

  # Error handling for path
  if(is.na(path)){path <- getwd()
  print(paste0("No path specified. Output saved to working directory: ", getwd()), quote = FALSE)
  } else if(!dir.exists(path)){
      stop("Specified directory does not exist.")
  } else{print(paste0("Output saving to ", path), quote = FALSE)}

  # Add / to end of path if it wasn't specified.
  path <- if(substr(path,nchar(path),nchar(path))!="/"){paste0(path,"/")} else {(paste0(path))}

  # Set up progress bar
  pb <- txtProgressBar(min = 0, max = length(view_list), style = 3)

  # Set up envir qualifier
  if(exists("VIEWS_NETN")){env = VIEWS_NETN} else {env = .GlobalEnv}

  # Export files
  if(zip == FALSE){
  invisible(lapply(seq_along(view_list), function(x){
    setTxtProgressBar(pb, x)
    write.csv(get(view_list[[x]], envir = env),
              paste0(path, view_list[x], ".csv"),
              row.names = FALSE)
 } else if(zip == TRUE){ #create tmp dir to export csvs, bundle to zip, then delete tmp folder

   dir.create(tmp <- tempfile())

   invisible(lapply(seq_along(view_list), function(x){
    setTxtProgressBar(pb, x)
    write.csv(get(view_list[[x]], envir = env),
              paste0(tmp, "\\", view_list[x], ".csv"),
              row.names = FALSE)}))

  file_list <- list.files(tmp)

  zip::zipr(zipfile = paste0(path, "NETN_Forest_", format(Sys.Date(), "%Y%m%d"), ".zip"),
            root = tmp,
            files = file_list)
  # csvs will be deleted as soon as R session is closed b/c tempfile
  noquote('Export complete.')
KateMMiller/forestNETN documentation built on May 30, 2021, 6:39 a.m.