[R-pkg-devel] Working with connections

[Glenn Schultz]

Hi All, 

I use connections to open and close data folders needed by my package.  After each function closes I get the following warnings (depending on the connection that has been opened).

10: closing unused connection 3 (/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/BondData/bondlabMBS4.rds) 

Below is the connection function that is related to the above warning:
  #------------------------------------------------------------------------------------
  #' A connection function to BondData calling MBS cusps
  #' 
  #' Opens a connection to the BondData folder to call MBS cusip data 
  #' @param MBS.id A character string the MBS.id or cusip number current MBS.id is supported
  #' @export
  MBS <- function(MBS.id = "character"){
                  MBS.Conn <- gzfile(description = paste(system.file(package = "BondLab"),
                              "/BondData/", MBS.id, ".rds", sep = ""), open = "rb")          
                  MBS <- readRDS(MBS.Conn)
                  return(MBS)
                  close.connection(MBS.Conn)
                  }

I have googled this warning and it seems to be triggered when a function terminates and the connection is open.  But, I think the connection function closes the connection once the object is returned.  What am I doing wrong?

-Glenn