closes #1 #2

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: flightsbr
 Title: Download Flight Data from Brazil
-Version: 0.0.1
+Version: 0.1.0
 Authors@R: 
     c(person(given="Rafael H. M.", family="Pereira", 
              email="rafa.pereira.br@gmail.com", 
@@ -25,7 +25,8 @@ Suggests:
     dplyr,
     ggplot2 (>= 3.3.1),
     rmarkdown (>= 2.6),
-    knitr
+    knitr,
+    testthat
 VignetteBuilder: 
     knitr
 Encoding: UTF-8

R/read_flights.R

@@ -8,53 +8,69 @@
 #' type, payload, and the number of passengers, and several other variables. A
 #' description of all variables included in the data is available at \url{https://www.anac.gov.br/assuntos/setor-regulado/empresas/envio-de-informacoes/descricao-de-variaveis}.
 #'
-#' @param year Numeric. Year of the data. Defaults to `2010`
-#' @param month Numeric. Year of the data. Defaults to `1` (January)
+#' @param date Numeric. Date of the data in the format `yyyymm`. Defaults to
+#'             `202001`. To download the data for all months in a year, the user
+#'             can pass a 4-digit year input `yyyy` .
 #' @param type String. Whether the data set should be of the type `basica`
-#' (flight stage, the default) or `combinada` (On flight origin and destination
-#' - OFOD).
+#'             (flight stage, the default) or `combinada` (On flight origin and
+#'             destination - OFOD).
 #' @param showProgress Logical. Defaults to `TRUE` display progress bar
+#' @param select A vector of column names or numbers to keep, drop the rest. The
+#'               order that the columns are specified determines the order of the
+#'               columns in the result.
 #'
 #' @return A `"data.table" "data.frame"` object
 #' @export
 #' @family download flight data
-
 #' @examples \dontrun{ if (interactive()) {
 #' # Read flights data
 #' a201506 <- read_flights(year=2015, month=6)
 #'}}
-read_flights <- function(year=2020, month=1, type='basica', showProgress=TRUE){
+read_flights <- function(date = 202001, type = 'basica', showProgress = TRUE, select = NULL){
 
 ### check inputs
-  # type
   if( ! type %in% c('basica', 'combinada') ){ stop(paste0("Argument 'type' must be either 'basica' or 'combinada'")) }
+  if( ! is.logical(showProgress) ){ stop(paste0("Argument 'showProgress' must be either 'TRUE' or 'FALSE.")) }
+  check_date(date=date)
 
-  # year and months perhaps use yyyymm ?
 
-  # progress bar
-  if( !(showProgress %in% c(T, F)) ){ stop("Value to argument 'showProgress' has to be either TRUE or FALSE") }
+if (nchar(date)==6) {
+#### Download one month---------------------------------------------------------
 
+# prepare address of online data
+  split_date(date)
+  file_url <- get_url(type=type, year=year, month=month)
 
-### prepare address of online data
-  if( nchar(month) ==1 ) { month <- paste0('0', month)}
-  url_root <- 'https://www.gov.br/anac/pt-br/assuntos/regulados/empresas-aereas/envio-de-informacoes/microdados/'
-  file_name <- paste0(type, year, '-', month, '.zip')
-  file_url <- paste0(url_root, file_name)
+# download and read data
+  dt <- download_flights_data(file_url, showProgress = showProgress, select = select)
+  return(dt)
 
-### download data
-  temp_local_file <- tempfile( file_name )
-  # utils::download.file(url = file_url, destfile = temp_local_file)
 
-  try(
-    httr::GET(url=file_url,
-             if(showProgress==T){ httr::progress()},
-              httr::write_disk(temp_local_file, overwrite = T),
-              config = httr::config(ssl_verifypeer = FALSE)
-    ), silent = F)
 
-### read zipped file stored locally
-  temp_local_file_zip <- paste0('unzip -p ', temp_local_file)
-  dt <- data.table::fread( cmd =  temp_local_file_zip)
-  return(dt)
-}
+
+} else if (nchar(date)==4) {
+#### Download whole year---------------------------------------------------------
+
+# prepare address of online data
+all_months <- generate_all_months(date)
+
+# manually ignore dates after Nov 2021
+if (date==2021) { all_months <- all_months[all_months < 202112] }
+
+dt_list <- lapply( X=all_months,
+                   FUN= function(i, type.=type, showProgress.=showProgress, select.=select) { # i = all_months[3]
+
+                      # prepare address of online data
+                      split_date(i)
+                      file_url <- get_url(type, year, month)
+
+                      # download and read data
+                      temp_dt <- download_flights_data(file_url, showProgress = showProgress, select = select)
+                      return(temp_dt)
+                      }
+                   )
+dt <- data.table::rbindlist(dt_list)
+return(dt)
+
+}}
 

R/utils.R

@@ -0,0 +1,132 @@
+# nocov start
+
+#' Split a date from yyyymmm to year yyyy and month mm
+#'
+#' @param date Numeric. Date of the data in the format `yyyymm`.
+#'
+#' @return An two string objects, `year` and `month`.
+#'
+#' @keywords internal
+split_date <- function(date) {
+
+  y <- substring(date, 1,4)
+  m <- substring(date, 5,6)
+
+  newList <- list("year" = y,
+                  "month" = m)
+  list2env(newList ,.GlobalEnv)
+}
+
+#' Check whether date input is acceptable
+#' @param date Numeric. Either a 6-digit date in the format `yyyymm` or a 4-digit
+#'             date input `yyyy` .
+#'
+#' @return Check messages.
+#'
+#' @keywords internal
+check_date <- function(date) {
+
+  # all dates between 2000 and 2021
+  all_dates <- lapply(X=2000:2021, FUN=generate_all_months)
+  all_dates <- unlist(all_dates)
+
+  # no data after 202111
+  all_dates <- all_dates[all_dates < 202111]
+
+
+  if (nchar(date)==6) {
+    if (!(date %in% all_dates)) {stop("Data only available for dates between Jan 2000 and Nov 2021.")}
+    }
+
+
+
+  if (nchar(date)==4) {
+    if (!(date %in% 2000:2021)) {stop("Data only available for dates between Jan 2000 and Nov 2021.")}
+    }
+
+}
+
+
+
+
+
+
+
+#' Generate all months with `yyyymm` format in a year
+#'
+#' @param date Numeric. 4-digit date in the format `yyyy`.
+#' @return Vector or strings.
+#' @keywords internal
+generate_all_months <- function(date) {
+
+  # check
+  if( nchar(date)!=4 ){ stop(paste0("Argument 'date' must be 4-digit in the format `yyyy`.")) }
+
+  jan <- as.numeric(paste0(date, '01'))
+  dec <- as.numeric(paste0(date, '12'))
+  all_months <- jan:dec
+  return(all_months)
+}
+
+
+
+#' Put together the data file url
+#'
+#' @param year Numeric. Year of the data in `yyyy` format.
+#' @param month Numeric. Month of the data in `mm` format.
+#' @param type String. Whether the data set should be of the type `basica`
+#'             (flight stage, the default) or `combinada` (On flight origin and
+#'             destination - OFOD).
+#'
+#' @return A url string.
+#'
+#' @keywords internal
+get_url <- function(type, year, month) {
+
+  if( nchar(month) ==1 ) { month <- paste0('0', month)}
+
+  url_root <- 'https://www.gov.br/anac/pt-br/assuntos/regulados/empresas-aereas/envio-de-informacoes/microdados/'
+  file_name <- paste0(type, year, '-', month, '.zip')
+  file_url <- paste0(url_root, file_name)
+  return(file_url)
+}
+
+
+
+
+
+
+#' Download and read ANAC flight data
+#'
+#' @param file_url String. A url passed from get_url.
+#' @param showProgress Logical, passed from \code{\link{read_flights}}
+#' @param select A vector of column names or numbers to keep, passed from \code{\link{read_flights}}
+#'
+#' @return A `"data.table" "data.frame"` object
+#'
+#' @keywords internal
+download_flights_data <- function(file_url, showProgress=showProgress, select=select){
+
+  # create temp local file
+  file_name <- substr(file_url, (nchar(file_url) + 1) -17, nchar(file_url) )
+  temp_local_file <- tempfile( file_name )
+
+  # download data
+  try(
+    httr::GET(url=file_url,
+              if(showProgress==T){ httr::progress()},
+              httr::write_disk(temp_local_file, overwrite = T),
+              config = httr::config(ssl_verifypeer = FALSE)
+    ), silent = F)
+
+  # read zipped file stored locally
+  temp_local_file_zip <- paste0('unzip -p ', temp_local_file)
+  dt <- data.table::fread( cmd =  temp_local_file_zip, select=select)
+  return(dt)
+  }
+
+## quiets concerns of R CMD check re: the .'s that appear in pipelines
+if(getRversion() >= "2.15.1") utils::globalVariables(
+  c('month', 'year'))
+
+# nocov end