Pkg name is a column in result, query multiple pkgs, #4

R/cranlogs.R

@@ -12,22 +12,19 @@ url <- "http://cranlogs.r-pkg.org/downloads/daily/"
 
 #' Daily package downloads from the RStudio CRAN mirror
 #'
-#' @param package A package to query, or \code{NULL} for a sum of
-#'   downloads for all packages.
+#' @param packages A character vector, the packages to query,
+#'   or \code{NULL} for a sum of downloads for all packages.
 #' @param when \code{last_day}, \code{last_week} or \code{last_month}.
 #'   If this is given, then \code{from} and \code{to} are ignored.
 #' @param from Start date, in \code{yyyy-mm-dd} format, or
 #'   \code{yesterday}. It is ignored if \code{when} is given.
 #' @param to End date, in \code{yyyy-mm-dd} format, or
 #'   \code{yesterday}. It is ignored if \code{when} is given.
-#' @return A list with entries: \itemize{
-#'   \item \code{downloads} The downloads, in a two-column data frame:
-#'     date and download count.
-#'   \item \code{start} Start date.
-#'   \item \code{end} End date.
-#'   \item \code{package} The queried package. This entry is missing
-#'     if the total number of downloads for all packages was queried.
-#' }
+#' @return A data frame with columns:
+#'   \item \code{package} The package. This column is missing if
+#'     all packages were queried.
+#'   \item \code{date} Day of the downloads.
+#'   \item \code{count} Download count.
 #'
 #' @export
 #' @examples
@@ -36,15 +33,18 @@ url <- "http://cranlogs.r-pkg.org/downloads/daily/"
 #' cran_downloads()
 #'
 #' ## All downloads for 'dplyr' yesterday
-#' cran_downloads(package = "dplyr")
+#' cran_downloads(packages = "dplyr")
 #'
 #' ## Daily downloads for 'igraph' last week
-#' cran_downloads(package = "igraph", when = "last-week")
+#' cran_downloads(packages = "igraph", when = "last-week")
 #'
 #' ## Downloads in the specified time interval
 #' cran_downloads(from = "2014-06-30", to = "2014-08-08")
+#'
+#' ## Multiple packages
+#' cran_downloads(packages = c("ggplot2", "plyr", "dplyr"))
 
-cran_downloads <- function(package = NULL,
+cran_downloads <- function(packages = NULL,
                            when = c("last-day", "last-week", "last-month"),
                            from = "last-day", to = "last-day") {
 
@@ -58,14 +58,39 @@ cran_downloads <- function(package = NULL,
     }
   }
 
-  if (is.null(package)) {
-    package <- ""
+  if (is.null(packages)) {
+    packages <- ""
   } else {
-    package <- paste0("/", package)
+    packages <- paste(packages, collapse = ",")
+    packages <- paste0("/", packages)
   }
 
-  r <- fromJSON(content(GET(paste0(url, interval, package)), as = "text"))
-  class(r) <- "cranlogs"
-  r
+  r <- fromJSON(content(GET(paste0(url, interval, packages)), as = "text"),
+                simplifyVector = FALSE)
+
+  to_df(r)
+
+}
 
+to_df <- function(res) {
+  if (length(res) == 1 && is.null(res[[1]]$package)) {
+    data.frame(
+      stringsAsFactors = FALSE,
+      date = sapply(res[[1]]$downloads, "[[", "day"),
+      count = sapply(res[[1]]$downloads, "[[", "downloads")
+    )
+
+  } else {
+    do.call(
+      rbind,
+      lapply(res, function(x) {
+        data.frame(
+          stringsAsFactors = FALSE,
+          package = x$package,
+          date = sapply(x$downloads, "[[", "day"),
+          count = sapply(x$downloads, "[[", "downloads")
+          )
+      })
+    )
+  }
 }

man/cran_downloads.Rd

@@ -3,12 +3,12 @@
 \alias{cran_downloads}
 \title{Daily package downloads from the RStudio CRAN mirror}
 \usage{
-cran_downloads(package = NULL, when = c("last-day", "last-week",
+cran_downloads(packages = NULL, when = c("last-day", "last-week",
   "last-month"), from = "last-day", to = "last-day")
 }
 \arguments{
-\item{package}{A package to query, or \code{NULL} for a sum of
-downloads for all packages.}
+\item{packages}{A character vector, the packages to query,
+or \code{NULL} for a sum of downloads for all packages.}
 
 \item{when}{\code{last_day}, \code{last_week} or \code{last_month}.
 If this is given, then \code{from} and \code{to} are ignored.}
@@ -20,14 +20,11 @@ If this is given, then \code{from} and \code{to} are ignored.}
 \code{yesterday}. It is ignored if \code{when} is given.}
 }
 \value{
-A list with entries: \itemize{
-  \item \code{downloads} The downloads, in a two-column data frame:
-    date and download count.
-  \item \code{start} Start date.
-  \item \code{end} End date.
-  \item \code{package} The queried package. This entry is missing
-    if the total number of downloads for all packages was queried.
-}
+A data frame with columns:
+  \item \code{package} The package. This column is missing if
+    all packages were queried.
+  \item \code{date} Day of the downloads.
+  \item \code{count} Download count.
 }
 \description{
 Daily package downloads from the RStudio CRAN mirror
@@ -37,12 +34,15 @@ Daily package downloads from the RStudio CRAN mirror
 cran_downloads()
 
 ## All downloads for 'dplyr' yesterday
-cran_downloads(package = "dplyr")
+cran_downloads(packages = "dplyr")
 
 ## Daily downloads for 'igraph' last week
-cran_downloads(package = "igraph", when = "last-week")
+cran_downloads(packages = "igraph", when = "last-week")
 
 ## Downloads in the specified time interval
 cran_downloads(from = "2014-06-30", to = "2014-08-08")
+
+## Multiple packages
+cran_downloads(packages = c("ggplot2", "plyr", "dplyr"))
 }