R/plot.R

In coinmarketcapr: Get 'Cryptocurrencies' Market Cap Prices from Coin Market Cap

#' Plot The Price of the Largest Market Cap Cryptocurrencies (API Key required)
#'
#' @param currency currency code (default is 'USD')
#' @param k the number of top cryptocurrencies to plot (default is 5)
#' @param bar_color a valid color name or hexadecimal color code (default is 'grey')
#' @return A ggplot of top Cryptocurrencies based on their rank (Market Cap)
#' @family Plotting
#' @examples \dontrun{
#' plot_top_currencies('EUR')
#' plot_top_currencies('GBP')
#' }
#' @export
plot_top_currencies <- function(currency = "USD", k = 5, bar_color = "grey") {

    stopifnot(currency %in% get_valid_currencies())

    k <- as.integer(k)
    if (k < 1)
        stop(cat(crayon::red(cli::symbol$cross,
                             "Parameter k must be a integer value greater than zero.\n")))

    # temp <- curl_fetch_memory(
    #     paste0("https://api.coinmarketcap.com/v1/ticker/?convert=",
    #            currency))
    # check_response(temp)
    # temp <- data.frame(fromJSON(rawToChar(temp$content)))

    temp <- coinmarketcapr::get_crypto_listings(currency = currency, limit = k)

    if (k > nrow(temp))
        warning(cat(crayon::yellow(cli::symbol$warning,
                                   "The argument provided to k is greater than the",
                                   "number of cryptocurrencies. Only", 4, "will be plotted.\n")))

    # temp <- temp[seq_len(min(k, nrow(temp))), ]
    #
    # temp[, tolower(paste0("price_", currency))] <- round(
    #     as.numeric(temp[, tolower(paste0("price_", currency))]), 2)

    ggplot(temp, aes_string("name", paste0(toupper(currency),"_price"))) +
        geom_bar(stat = 'identity', fill = bar_color) +
        ylab(paste0("Price in ", currency)) +
        xlab("Cryptocurrencies") +
        ggtitle(paste0("Top ", k, " Cryptocurrencies with Largest Marketcaps"))
}