R/af_load.R

In mdaku/afrobar: A simple helper package for working with Afrobarometer data

#' Loads the Afrobarometer dataset
#'
#' @name af_load
#' @param round A number specifying which round of the Afrobarometer to load (6 by default)
#' @param force A boolean specifiying whether or not to force the download of a new copy from the website (false by default)
#' @param clean A boolean specifying whether or not to clean the dataset (TRUE by default)
#' @return Returns the dataframe \code{afro}, and sets a global integer \code{af.round}
#' @examples
#'
#' # Load the 6th round of the Afrobarometer from local file if available,
#' # or from the website if the local file does not exist
#' af_load()
#'
#' # Download and load the 5th round of the Afrobarometer, ignoring and
#' # overwriting any local files that exist
#' af_load(5, force=T)
#'
#' # Download and load the 3rd round of the Afrobarometer, ignoring and
#' # overwriting any local files that exist, do not automatically clean
#' af_load(5, force=T, clean=F)
#' @export
#'



# Load libraries

library(tidyverse)
library(haven)

# Functions
af_load <- function(round=6, force=FALSE, clean=TRUE){
  # Specifies the round and whether or not to force the download
  # This may be complicated, as the connection is usually weak
  if (round == 6){
    # 2016
    url <- "http://afrobarometer.org/sites/default/files/data/round-6/merged_r6_data_2016_36countries2.sav"
    fname <- "merged_r6_data_2016_36countries2.sav"
    af_round <<- 6
  }
  else if (round == 5){
    url <- "http://afrobarometer.org/sites/default/files/data/round-5/merged-round-5-data-34-countries-2011-2013-last-update-july-2015.sav"
    fname <- "merged-round-5-data-34-countries-2011-2013-last-update-july-2015.sav"
    warning("Afrobarometer round 5 is not the most recent round of data")
    af_round <<- 5
  }
  else if (round ==4){
    url <- "http://afrobarometer.org/sites/default/files/data/round-4/merged_r4_data.sav"
    fname <- "round-4/merged_r4_data.sav"
    warning("Afrobarometer round 4 is not the most recent round of data")
    af_round <<- 4
  }
  else if (round ==3){
    url <- "http://afrobarometer.org/sites/default/files/data/round-3/merged_r3_data.sav"
    fname <- "merged_r3_data.sav"
    warning("Afrobarometer round 3 is not the most recent round of data")
    af_round <<- 3
  }
  else if (round ==2){
    url <- "http://afrobarometer.org/sites/default/files/data/round-2/merged_r2_data.sav"
    fname <- "merged_r2_data.sav"
    warning("Afrobarometer round 2 is not the most recent round of data")
    af_round <<- 2
  }
  else if (round ==1){
    url <- "http://afrobarometer.org/sites/default/files/data/round-1/merged_r1_data.sav"
    fname <- "merged_r1_data.sav"
    warning("Afrobarometer round 1 is not the most recent round of data")
    af_round <<- 1
  }
  else{
    stop("Only Afrobarometer rounds 1-6 are currently available")
  }

  # Download the file & load it as an SPSS file

  # First, check to see if the file exists locally
  if (file.exists(fname) & force==FALSE){
    # Does the file exist?
    message("Loading local file")
    afro <- read_sav(fname)
  }
  else{
    # Downloading file from Afrobarometer.org
    message("Downloading file from Afrobarometer.org")
    download.file(url, fname)
    afro <- read_sav(fname)
    # Does this work?
    if (is.null(afro)) af_round <<- NULL

  }
  if (clean){
    message("Cleaning source file")
    afro <- af_clean(afro)
  }
  else{
    warning("Afrobarometer data has *not* been cleaned")
  }
  # This will return the wrong af_round if it fails
  afro
}