R/traffic_history.R

In aws.alexa: Client for the Amazon Alexa Web Information Services API

#' Get Traffic History of a URL
#'
#' @param url String; Required; valid url
#' @param range Integer; Required; Default is 31, Maximum is 31. Pick an integer between 1 and 31.
#' @param start String; Optional; A date within the last 4 years in format YYYYMMDD.
#' @param \dots Additional arguments passed to \code{\link{alexa_GET}}.
#'
#' @return data.frame with the following columns: \code{site, start, range,
#' date, page_views_per_million, page_views_per_user, rank, reach_per_million}
#'
#' @export
#' @references \url{https://docs.aws.amazon.com/AlexaWebInfoService/latest/ApiReference_TrafficHistoryAction.html}
#'
#' @examples \dontrun{
#' traffic_history(url = "http://www.google.com", start = "20160505")
#' }

traffic_history <- function(url = NULL, range = 31, start = NULL, ...) {

    if (!is.character(url)) {
        stop("Must specify url")
    }

    if (!is.numeric(range) | (range < 1 | range > 31)) {
        stop("Range must be between 1 and 31.")
    }

    if (!is.null(start)) {
      if (is.na(as.Date(start, "%Y%m%d"))) {
        stop("Date is not in the right format. The correct format is YYYYMMDD")
      }
    }

    query <-  list(Action = "TrafficHistory", Url = url,
                        ResponseGroup = "History", Range = range, Start = start)
    traffic_payload <- alexa_GET(query, ...)

    res  <- bind_rows(lapply(
                traffic_payload[[1]]$TrafficHistoryResult[[1]]$TrafficHistory$HistoricalData,
                function(x)
                c(date = x$Date,
                  page_views_per_million = x$PageViews$PerMillion,
                  page_views_per_user = x$PageViews$PerUser,
                  rank = x$Rank,
                  reach_per_million = x$Reach$PerMillion)
                )
            )

    stem   <- traffic_payload$Response$TrafficHistoryResult$Alexa$TrafficHistory
    basics <- data.frame(site = stem$Site[[1]],
                         start = stem$Start[[1]],
                         range = stem$Range[[1]])

    cbind(basics, res)
}