Share contact infos with Crossref

R/rcrossref-package.R

@@ -66,6 +66,26 @@
 #' citations will be added to a file called `crossref.bib`. New citations
 #' will be appended to that file. Addin authored by Hao Zhu
 #' <https://github.com/haozhu233>
+#' 
+#' @section Be nice and share your email with Crossref:
+#' The Crossref team encourage requests with appropriate contact information 
+#' and will forward you to a dedicated API cluster for improved performance when 
+#' you share your email address with them.
+#' <https://github.com/CrossRef/rest-api-doc#good-manners--more-reliable-service>
+#' 
+#' To pass your email address to Crossref via this client, simply store it 
+#' as environment variable in `.Renviron` like this:
+#' 
+#' 1. Open file:
+#' `file.edit("~/.Renviron")`
+#' 
+#' 2. Add email address to be shared with Crossref
+#' `crossref_email = name@example.com`
+#' 
+#' 3. Save the file and restart your R session
+#' 
+#' Don't wanna share your email any longer? Simply delete it from 
+#' `~/.Renviron`
 #'
 #' @importFrom methods as
 #' @importFrom utils modifyList packageVersion

R/zzz.R

@@ -16,14 +16,17 @@ rcrossref_ua <- function() {
   versions <- c(paste0("r-curl/", utils::packageVersion("curl")),
                 paste0("crul/", utils::packageVersion("crul")),
                 sprintf("rOpenSci(rcrossref/%s)", 
-                        utils::packageVersion("rcrossref")))
+                        utils::packageVersion("rcrossref")),
+                get_email())
   paste0(versions, collapse = " ")
 }
 
-cr_GET <- function(endpoint, args, todf = TRUE, on_error = warning, parse = TRUE, ...) {
+cr_GET <- function(endpoint, args, todf = TRUE, on_error = warning, parse = TRUE, 
+                   ...) {
   url <- sprintf("https://api.crossref.org/%s", endpoint)
   cli <- crul::HttpClient$new(
     url = url,
+    opts = list(verbose = TRUE),
     headers = list(
       `User-Agent` = rcrossref_ua(),
       `X-USER-AGENT` = rcrossref_ua()
@@ -154,3 +157,41 @@ prep_args <- function(query, filter, offset, limit, sample, sort,
 }
 
 `%||%` <- function(x, y) if (is.null(x) || length(x) == 0) y else x
+
+
+#' Share email with Crossref in `.Renviron`
+#' 
+#' @noRd
+get_email <- function() {
+  email <- Sys.getenv("crossref_email")
+  if (identical(email, "")) {
+    NULL
+  } else {
+  paste0("(mailto:", val_email(email), ")")
+  }
+}
+
+#' Email checker
+#'
+#' It implementents the following regex stackoverflow solution
+#' http://stackoverflow.com/a/25077140
+#'
+#' @param email email address (character string)
+#'
+#' @noRd
+val_email <- function(email) {
+  if (!grepl(email_regex(), email))
+    stop("Email address seems not properly formatted - Please check your .Renviron!",
+         call. = FALSE)
+  return(email)
+}
+
+#' Email regex
+#'
+#' From \url{http://stackoverflow.com/a/25077140}
+#'
+#' @noRd
+email_regex <-
+  function()
+    "^[_a-z0-9-]+(\\.[_a-z0-9-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)*(\\.[a-z]{2,4})$"
+