# install.packages("devtools")
library(devtools)
install_github("mikeasilva/blsAPI")

## BLS API.R 
  # 
  #' This function allows users to request data from the BLS API.   
  #' See https://www.bls.gov/developers/ and https://www.bls.gov/developers/api_signature.htm for more details. 
  #' @param data Information to send to the API. 
#' @keywords bls api economics 
#' @export 
#' @examples 
#' ## These examples are taken from https://www.bls.gov/developers/api_signature.htm 
  #'  
  #' ## Single Series request 
  #' response <- blsAPI('LAUCN040010000000005') 
  #' json <- fromJSON(response) 
  #'  
  #' ## Multiple Series  
  #' payload <- list('seriesid'=c('LAUCN040010000000005','LAUCN040010000000006')) 
  #' response <- blsAPI(payload) 
  #' json <- fromJSON(response) 
  #'  
  #' ## One or More Series, Specifying Years 
  #' payload <- list('seriesid'=c('LAUCN040010000000005','LAUCN040010000000006'), 'startyear'='2010', 'endyear'='2012') 
  #' response <- blsAPI(payload) 
  #' json <- fromJSON(response) 
 
blsAPI <- function(data=NA){ 
  require(rjson) 
  require(RCurl) 
  h = basicTextGatherer() 
  h$reset() 
  if(is.na(data)){ 
    message('blsAPI: No parameters specified.') 
    } 
  else{ 
      ## Parameters specified so make the request 
      if(is.list(data)){ 
      ## Multiple Series or One or More Series, Specifying Years request 
      curlPerform(url='https://api.bls.gov/publicAPI/v1/timeseries/data/', 
                  httpheader=c('Content-Type' = "application/json;"), 
                  postfields=toJSON(data), 
                  verbose = FALSE,  
                 writefunction = h$update 
                  ) 
      }else{ 
          ## Single Series request 
          curlPerform(url=paste0('https://api.bls.gov/publicAPI/v1/timeseries/data/',data), 
                      verbose = FALSE,  
                      writefunction = h$update 
                      ) 
            } 
        } 
      h$value() 
    }



response <- blsAPI('LAUCN040010000000005')