Create ds.retStr.R

ds.retStr.R

@@ -0,0 +1,67 @@
+#' @title Passes a string to a server-side environment
+#' @description Passes a string to a server side environment and prints the string returned from the server. 
+#' @details This is a function to test writing new functions and the communication between the client and the server. 
+#' 
+#' Server function called: \code{retStrDS}. 
+#' 
+#' @param search.filter character string (potentially including \code{*} symbol without spaces) 
+#' specifying the string that you want to pass to the server-side.
+#' For more information see \strong{Details}. 
+#' @return \code{ds.retStr} returns to the client-side a string
+#' @author Soumya Banerjee, 2020
+#' @examples
+#' \dontrun{
+#'
+#'   ## Version 6
+#'   
+#'   # connecting to the Opal servers
+#' 
+#'   require('DSI')
+#'   require('DSOpal')
+#'   require('dsBaseClient')
+#'
+#'   builder <- DSI::newDSLoginBuilder()
+#'   builder$append(server = "study1", 
+#'                  url = "http://192.168.56.100:8080/", 
+#'                  user = "administrator", password = "datashield_test&", 
+#'                  table = "CNSIM.CNSIM1", driver = "OpalDriver")
+#'   builder$append(server = "study2", 
+#'                  url = "http://192.168.56.100:8080/", 
+#'                  user = "administrator", password = "datashield_test&", 
+#'                  table = "CNSIM.CNSIM2", driver = "OpalDriver")
+#'   builder$append(server = "study3",
+#'                  url = "http://192.168.56.100:8080/", 
+#'                  user = "administrator", password = "datashield_test&", 
+#'                  table = "CNSIM.CNSIM3", driver = "OpalDriver")
+#'   logindata <- builder$build()
+#'   
+#'   connections <- DSI::datashield.login(logins = logindata, assign = TRUE, symbol = "D") 
+#'   
+#'   ds.retStr('hello')
+#'   
+#'   # clear the Datashield R sessions and logout
+#'   datashield.logout(connections)
+#' }
+#'
+#' @export
+ds.retStr <- function(search.filter=NULL)
+{
+
+   datasources <- datashield.connections_find()
+
+   # call the server side function
+   cat("On client side: \n")
+   calltext <- call("retStrDS",search.filter=search.filter)
+
+   cat("\n Class of calltext\n")
+   cat(class(calltext))
+   cat("\n What is in calltext ? \n")
+   cat(as.character(calltext))
+   cat("\n End of function \n")	
+
+   output <- datashield.aggregate(datasources, calltext)
+
+   return(output)
+
+}
+#ds.retStr