R/the-web.R

In libbib: Various Utilities for Library Science/Assessment and Cataloging

#' Get Library of Congress catalog permalinks from LCCNs
#'
#' Takes a string representation of an LCCNs. Returns permalinks
#' to the Library of Congress catalog entries using those LCCNs.
#'
#' @param x A string (or vector of strings) of LCCNs
#' @param normalize a logical indicating whether the LCCN should be
#'                  normalized prior to creating the permalink
#'                  (default is \code{TRUE})
#' @param format One of "", "marcxml", "mods", "mads", or "dublin" to return
#'               the link to the main permalink page, or the link directly
#'               to the record's MARCXml, MODS, MADS, or Dublin Core
#'               representation, respectively.
#'
#' @details
#' If normalize=TRUE and the LCCN is invalid, the permalink is NA.
#' If normalize=FALSE, the permalink may be invalid. No validity
#' check on the URL is performed
#'
#' @return Library of Congress permalinks using LCCNs.
#'
#' @examples
#' loc_permalink_from_lccn("n78-890351")        # "https://lccn.loc.gov/n78890351"
#' loc_permalink_from_lccn("85-2 ")             # "https://lccn.loc.gov/85000002"
#' loc_permalink_from_lccn("75-425165//r75")    # "https://lccn.loc.gov/75425165"
#'
#' # vectorized
#' loc_permalink_from_lccn(c("###78890351#", NA, "n78-890351"))
#'
#' # MARCXML metadata format
#' loc_permalink_from_lccn("73167510", format="marcxml")
#' # "https://lccn.loc.gov/73167510/marcxml"
#'
#' @export
loc_permalink_from_lccn <- function(x, normalize=TRUE, format=""){
  if(all(is.na(x))) return(as.character(x))
  if(!methods::is(x, "character"))
    stop("Input must be a character string")

  postfix <- fcase(format=="",         "",
                   format=="marcxml",  "/marcxml",
                   format=="mods",     "/mods",
                   format=="mads",     "/mads",
                   format=="dublin",   "/dc",
                   (!(format %in% c("marcxml", "mods", "mads", "dublin"))),
                     stop('format must be one of "", "marcxml", "mods", "mads", or "dublin"'))

  if(normalize)
    x <- normalize_lccn(x)

  ifelse(is.na(x), NA_character_,
         sprintf("https://lccn.loc.gov/%s%s", x, postfix))
}


#' Get WorldCat catalog permalinks from ISSNs
#'
#' Takes a string representation of ISSNs. Returns permalinks
#' to the WorldCat catalog entries using those ISSNs.
#'
#' @param x A string (or vector of strings) of ISSNs
#' @param normalize a logical indicating whether the ISSNs should be
#'                  normalized prior to creating the permalink
#'                  (default is \code{TRUE})
#'
#' @details
#' If normalize=TRUE and the ISSN is invalid, the permalink is NA.
#' If normalize=FALSE, the permalink may be invalid. No validity
#' check on the URL is performed
#'
#' @return Worldcat permalinks using ISSNs.
#'
#' @examples
#' worldcat_permalink_from_issn("0968-1221")   # http://www.worldcat.org/issn/0968-1221
#'
#' worldcat_permalink_from_issn("2434-561X")   # http://www.worldcat.org/issn/2434561X
#'
#' # vectorized
#' worldcat_permalink_from_issn(c("0968-1221", NA, "2434-561X"))
#'
#' @export
worldcat_permalink_from_issn <- function(x, normalize=TRUE){
  if(all(is.na(x))) return(as.character(x))
  if(!methods::is(x, "character"))
    stop("Input must be a character string")
  if(normalize)
    x <- normalize_issn(x)

  ifelse(is.na(x), NA_character_,
         sprintf("http://www.worldcat.org/issn/%s", x))
}


#' Get WorldCat catalog permalinks from ISBNs
#'
#' Takes a string representation of ISBNs. Returns permalinks
#' to the WorldCat catalog entries using those ISBNs.
#'
#' @param x A string (or vector of strings) of ISBNs
#' @param normalize a logical indicating whether the ISBNs should be
#'                  normalized prior to creating the permalink
#'                  (default is \code{TRUE})
#'
#' @details
#' If normalize=TRUE and the ISBN is invalid, the permalink is NA.
#' If normalize=FALSE, the permalink may be invalid. No validity
#' check on the URL is performed
#'
#' @return Worldcat permalinks using ISBNs.
#'
#' @examples
#'
#' worldcat_permalink_from_isbn("1788393724")
#' # http://www.worldcat.org/isbn/1788393724
#'
#' worldcat_permalink_from_isbn("0-124-91540-X")
#' # http://www.worldcat.org/isbn/012491540X
#'
#' worldcat_permalink_from_isbn("0-124-91540-X", normalize=FALSE)
#' # http://www.worldcat.org/isbn/0-124-91540-X
#'
#' # vectorized
#' worldcat_permalink_from_isbn(c("1788393724", NA, "0-124-91540-X"))
#'
#' @export
worldcat_permalink_from_isbn <- function(x, normalize=TRUE){
  if(all(is.na(x))) return(as.character(x))
  if(!methods::is(x, "character"))
    stop("Input must be a character string")
  if(normalize)
    x <- normalize_isbn(x)

  ifelse(is.na(x), NA_character_,
         sprintf("http://www.worldcat.org/isbn/%s", x))
}


#' Get WorldCat catalog permalinks from OCLC numbers
#'
#' Takes a string representation of OCLC numbers. Returns permalinks
#' to the WorldCat catalog entries using those OCLC numbers
#'
#' @param x A string (or vector of strings) of OCLC numbers
#'
#' @details
#' No validity check on the URL is performed
#'
#' @return Worldcat permalinks using the OCLC numbers
#'
#' @examples
#'
#' worldcat_permalink_from_oclc_number("1005106045")
#' # http://www.worldcat.org/oclc/1005106045
#'
#' # vectorized
#' worldcat_permalink_from_oclc_number(c("1049727704", NA,
#'                                       "1005106045"))
#'
#' @export
worldcat_permalink_from_oclc_number <- function(x){
  if(all(is.na(x))) return(as.character(x))
  if(!methods::is(x, "character"))
    stop("Input must be a character string")
  x <- stringr::str_replace_all(x, "\\s", "")
  ifelse(is.na(x), NA_character_,
         sprintf("http://www.worldcat.org/oclc/%s", x))
}



#' Get OCLC Classify link from a standard number
#'
#' Takes a string representation of ISSNs, ISBNs, UPC,
#' or OCLC numbers.
#' Returns a link to the OCLC's experimental classify
#' service which provides the most frequent call numbers,
#' FAST subject headings, etc...
#'
#' @param x A string (or vector of strings) of a standard number.
#'          Must be an ISSN, ISBN, UPC, and/or OCLC numbers.
#'
#' @details
#' Since this can take a variety of standard numbers, no
#' normalization can be performed. The numbers much be normalized
#' before the call to this function.
#' No validity check on the URL is performed
#'
#' @return Links to OCLC's Classify web service
#'
#' @examples
#'
#' oclc_classify_link_from_standard_num("629725006")
#' # "http://classify.oclc.org/classify2/ClassifyDemo?search-standnum-txt=629725006&startRec=0"
#'
#' oclc_classify_link_from_standard_num(c("039333712X", NA, "629725006"))
#' # [1] "http://classify.oclc.org/classify2/ClassifyDemo?search-standnum-txt=039333712X&startRec=0"
#' # [2] NA
#' # [3] "http://classify.oclc.org/classify2/ClassifyDemo?search-standnum-txt=629725006&startRec=0"
#'
#' @export
oclc_classify_link_from_standard_num <- function(x){
  if(all(is.na(x))) return(as.character(x))
  if(!methods::is(x, "character"))
    stop("Input must be a character string")
  x <- stringr::str_replace_all(x, "\\s", "")
  part1 <- "http://classify.oclc.org/classify2/ClassifyDemo?search-standnum-txt="
  part2 <- "&startRec=0"
  ret <- sprintf("%s%s%s", part1, x, part2)
  ret[is.na(x)] <- NA_character_
  return(ret)
}