Demo using googleAuthR to create a Google API package

url_short.R

library(googleAuthR)

## change the native googleAuthR scopes to the one needed.
options("googleAuthR.scopes.selected" = 
        c("https://www.googleapis.com/auth/urlshortener"))

#' Shortens a url using goo.gl
#'
#' @param url URl to shorten with goo.gl
#' 
#' @return a string of the short URL
shorten_url <- function(url){

  body = list(
    longUrl = url
  )

  f <- gar_api_generator("https://www.googleapis.com/urlshortener/v1/url",
                         "POST",
                         data_parse_function = function(x) x$id)

  f(the_body = body)

}

#' Expands a url that has used goo.gl
#'
#' @param shortUrl Url that was shortened with goo.gl
#' 
#' @return a string of the expanded URL
expand_url <- function(shortUrl){

  f <- gar_api_generator("https://www.googleapis.com/urlshortener/v1/url",
                         "GET",
                         pars_args = list(shortUrl = "shortUrl"),
                         data_parse_function = function(x) x)

  f(pars_arguments = list(shortUrl = shortUrl))

}

#' Get analyitcs of a url that has used goo.gl
#'
#' @param shortUrl Url that was shortened with goo.gl
#' @param timespan The time period for the analytics data
#' 
#' @return a dataframe of the goo.gl Url analytics
analytics_url <- function(shortUrl, 
                          timespan = c("allTime", "month", "week","day","twoHours")){

  timespan <- match.arg(timespan)

  f <- gar_api_generator("https://www.googleapis.com/urlshortener/v1/url",
                         "GET",
                         pars_args = list(shortUrl = "shortUrl",
                                          projection = "FULL"),
                         data_parse_function = function(x) { 
                                    a <- x$analytics 
                                    return(a[timespan][[1]])
                                    })

  f(pars_arguments = list(shortUrl = shortUrl))
}

#' Get the history of the authenticated user
#' 
#' @return a dataframe of the goo.gl user's history
user_history <- function(){
  f <- gar_api_generator("https://www.googleapis.com/urlshortener/v1/url/history",
                         "GET",
                         data_parse_function = function(x) x$items)

  f()
}

## To use the above functions:
library(googleAuthR)

# go through authentication flow
gar_auth()

s <- shorten_url("http://markedmondson.me")
s

expand_url(s)

analytics_url(s, timespan = "month")

user_history()