Get package host

Overview

This vignette demonstrates how to use a set of R functions to programmatically retrieve the URL and code host package hosted on CRAN, Bioconductor and Github.

We will walk through each step, from checking if a package exists on CRAN to fetching its version history and constructing an appropriate download URL.

CRAN

library(DT)
library(risk.assessr)

Check if the Package Exists on CRAN

risk.assessr:::check_cran_package("here")

Parse Package Archive HTML from CRAN database

fetch information from “https://cran.r-project.org/src/contrib/Archive/here/”

html <- risk.assessr:::parse_package_info("here")
html

Extract Version Information from the Archive Page

Create table with package_name, package_version, link, date, size from CRAN website

Get All Versions and the Latest Version

version_info <- risk.assessr:::get_versions(table, "here")
version_info$last_version

Get CRAN package URL source code

url <- risk.assessr:::get_cran_package_url(
  package_name = "here",
  version = NULL,
  last_version = version_info$last_version,
  all_versions = version_info$all_versions
)
url

Internal R package

risk.assessr can also provide similar information from Internal mirror

result_intern <- risk.assessr:::get_internal_package_url("herald")

result_intern$url

result_intern$last_version

Bioconductor package

Steps to get an R package stored on Bioconductor

html_content <- fetch_bioconductor_releases()
release_data <- parse_bioconductor_releases(html_content)
result_bio <- get_bioconductor_package_url("flowCore", "2.18.0", release_data)

result_bio$url

Github repository

R packages stored on Github are assess by looking at BugReports or URL in DESCRIPTION file to find a owner. github link are then created such as below and used to request Github API.

urls <- c(
  "https://github.com/tidyverse/ggplot2"
)
bug_reports <- c(
  "https://github.com/tidyverse/ggplot2/issues"
)

all_links <- c(urls, bug_reports)

github_pattern <- "https://github.com/([^/]+)/([^/]+).*"
matching_links <- grep(github_pattern, all_links, value = TRUE)
owner_names <- sub(github_pattern, "\\1", matching_links)
package_names_github <- sub(github_pattern, "\\2", matching_links)

valid <- which(owner_names != "" & package_names_github != "")

  if (length(valid) > 0) {
    github_links <- unique(paste0("https://github.com/", owner_names[valid], "/", package_names_github[valid]))
  } else {
    github_links <- NULL
  }

github_links