compare_versions.md

title	author	date	output
Compare Versions	Philipp Ottolinger	8 April 2016	html_document

get_github_version <- function(url) {
  repo <- gsub("https://github.com/", url, replacement = "")
  raw_description_str <- paste("https://raw.githubusercontent.com/", repo, "/master/DESCRIPTION", sep = "")
  raw_description <- getURL(raw_description_str)
  # better use some regex here!
  version <- sapply(strsplit(raw_description, "Version: "), "[", 2)
  version <- sapply(strsplit(version, "\n"), "[", 1)
  return(version)
}

url <- "https://github.com/daattali/shinyjs"
get_github_version(url)

## [1] "0.5.3"

get_cran_version <- function(package) {
  url <- paste("https://cran.r-project.org/web/packages/", package, "/", sep = "")
  file <- getURL(url)
  # better use some regex here!
  version <- sapply(strsplit(file, "Version:</td>\n<td>"), "[", 2)
  version <- sapply(strsplit(version, "<"), "[", 1)
  return(version)
}

package <- "shinyjs"
get_cran_version(package)

## [1] "0.5.2"

compare_versions <- function(CRAN, GitHub) {
  table <- data.frame("CRAN" = get_cran_version(CRAN),
                      "GitHub" = get_github_version(GitHub))
  rownames(table) <- "Version"
  return(table)
}

compare_versions(CRAN = package, GitHub = url)

##          CRAN GitHub
## Version 0.5.2  0.5.3