R/apiGET.R

In ceparman/Core5.3: Core API fucntions

#' apiGET - Do a get from the Core ODATA REST API.
#'
#' \code{apiGET}  Base call to Core REST API.
#' @param coreApi coreApi object with valid jsessionid
#' @param resource entity type to get
#' @param query query string
#' @param headers  headers to be added to get
#' @param special passed to buildUrl for special sdk endpoints
#' @param useVerbose Use verbose communication for debugging
#' @export
#' @return Returns a list of length two. First the content, concatenated if a chunked response, and second the entire http response.
#'If chuncked for the content for the last chunk only.last 

#' @examples
#'\dontrun{
#' api<-CoreAPIV2::CoreAPI("PATH TO JSON FILE")
#' login<- CoreAPIV2::authBasic(api)
#' response <-CoreAPIV2::apiGET(login$coreApi,"json",resource,query)
#' content <- response$content
#' error <- httr::http_error(response$response)
#' CoreAPIV2::logOut(login$coreApi)
#' }
#'@author Craig Parman ngsAnalytics, ngsanalytics.com
#'@description \code{apiGET} - Do a get from the Core ODATA REST API.


apiGET <-
  function(coreApi,
           resource,
           query,
           headers = NULL,
           special = NULL,
           useVerbose = FALSE)
  {
    #clean the resource name for ODATA
    
    resource <- CoreAPIV2::ODATAcleanName(resource)
    
    sdk_url <-
      CoreAPIV2::buildUrl(
        coreApi,
        resource = resource,
        query = query,
        special = NULL,
        useVerbose = useVerbose
      )
    base_sdk_url <-
      sdk_url  #need if we need to build url for additional chunks
    
    cookie <-
      c(JSESSIONID = coreApi$jsessionId,
        AWSELB = coreApi$awselb)
    
    #Get first response
    
    if (useVerbose) {
      response <-
        httr::with_verbose(httr::GET(
          sdk_url,
          httr::add_headers(headers),
          httr::set_cookies(cookie)
        ))
      
    } else  {
      response <- httr::GET(sdk_url,
                            httr::add_headers(headers),
                            httr::set_cookies(cookie))
      
    }
    
    #check for general HTTP error in response
    
    if (httr::http_error(response)) {
      stop({
        print("API call failed")
        print(httr::http_status(response))
      },
      call. = FALSE)
      
    }
    #determine if this is a chunked response
    
    
    if (!is.null(httr::headers(response)$'transfer-encoding'))
    {
      chunked <-
        (httr::headers(response)$'transfer-encoding' == "chunked")
      
    } else
      chunked <- FALSE
    
    chunked <-
      !is.null(httr::content(response)$`@odata.nextLink`) ### added to account for chunked header when not really chunked
    
    #two methods for chunked and not chunked
    # it appears sometimes we get a content$value and sometimes we get just content
    
    if (!chunked) {
      #not chunked response
      if (is.null(httr::content(response)[["value"]])) {
        content <- httr::content(response)
      } else
        content <- httr::content(response)$value
      
    } else
    {
      #chunked response
      more_content <- TRUE #flag for more chunks
      
      skiptoken <- 1  #counter for chunks
      
      content <- httr::content(response)$value
      
      
      while (more_content)
        
      {
        #build url for next chunk
        sdk_url <- paste0(base_sdk_url, "?$skiptoken=", skiptoken)
        
        skiptoken <- skiptoken + 1
        
        #get next data chunk
        
        #
        if (useVerbose) {
          response <-
            httr::with_verbose(httr::GET(sdk_url, httr::add_headers(headers)),
                               httr::set_cookies(cookie))
          
        } else  {
          response <- httr::GET(sdk_url,
                                httr::add_headers(headers),
                                httr::set_cookies(cookie))
          
        }
        #add content
        
        content <- c(content, httr::content(response)$value)
        
        #Is there more content ?
        
        more_content <-
          !is.null(httr::content(response)$`@odata.nextLink`)
      }
      
      
      
      
    }
    
    
    
    out <- list(content = content, response = response)
    
    return(out)
  }