Loading an object into the global environment in an R package using .onLoad ()

I'm working on an R package in which I need to manage the state of various objects over time. Conceptually, when a package is loaded (.onLoad), it checks the state object in the cache, and if it doesn't exist, a new instance is created, stored in the cache, and assigned in the global environment. Ive been unable to see the object in the global environment using .onLoad () after building the site with devtools :: build (). So, I have three questions:

• Is the .onLoad () function the right place for this function? If so, what is the current best practice for displaying state variables in a global environment?
• Has a solution (package) been developed to manage state through "R sessions"?
• Is there a more conceptual approach to the problem than the one I've taken?

Solutions tried ... so far

Ive scoured SE, read (and reread) Hadleys books on R packages and Advanced R, conceived Winston Changs vignettes on R6 (links at the bottom of the post), and Ive pushed my experiments to three failed approaches. First, it is a simple "GameClass" that creates a game with three variables, player 1, player 2, and state (of the game).

 #' GameClass
 #' \code{GameClass} Class that...#'
 #' @export
 GameClass <- R6::R6Class(
   "GameClass",
   public = list(
     player1 = character(0),
     player2 = character(0),
     state  = character(0),
     initialize = function(player1, player2) {
       self$player1 <- player1
       self$player2 <- player2
       self$state <- "1st Match"
     }
   )
 )

      

        
        
        
      

    

Approach 1

  Assign the variable to the global environment using the <<- operator


  .onLoad <- function(libname, pkgname) {

    gameFile <- "./gameFile.Rdata"
    if (file.exists(gameFile)) {
      game <<- load(gameFile)
    } else {
     game  <<- GameClass$new("Eric", "Cassie")
     save(game, file = gameFile)
    } 
  }

      

        
        
        
      

    

Approach 2:

Create a new environment and bring it back

  .onLoad <- function(libname, pkgname) {
    gameFile <- "./gameFile.Rdata"
    e <- new.env()

    if (file.exists(gameFile)) {
      e$game <- load(gameFile)
    } else {
      e$game <- GameClass$new("Eric", "Cassie")
      save(e$game, file = gameFile)
    }  
    e
  }

      

        
        
        
      

    

Approach 3:

  .onLoad <- function(libname, pkgname) {
    gameFile <- "./gameFile.Rdata"

    if (file.exists(gameFile)) {
      game <- load(gameFile)
    } else {
      game <- GameClass$new("Eric", "Cassie")
      save(game, file = gameFile)
    }
    assign("game", game, envir = .GlobalEnv)
  }

      

        
        
        
      

    

Session information

 R version 3.4.1 (2017-06-30)
 Platform: x86_64-w64-mingw32/x64 (64-bit)
 Running under: Windows >= 8 x64 (build 9200)

 Matrix products: default

 locale:
 [1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United 
 States.1252    LC_MONETARY=English_United States.1252
 [4] LC_NUMERIC=C                           LC_TIME=English_United 
 States.1252    

 attached base packages:
 [1] stats     graphics  grDevices utils     datasets  methods   base     

 other attached packages:
 [1] R6Lab_0.1.0

 loaded via a namespace (and not attached):
 [1] compiler_3.4.1 R6_2.2.2       tools_3.4.1    yaml_2.1.14   

      

        
        
        
      

    

I'm new to OOP, new to R6, this is my first R package and I've been playing with R for a year now. Obviously, I could benefit from some insights here.

Thanks in advance.

## References ##
[Hadley Advanced R][1]
[Hadley R Packages][2]
[Introduction to R6 Classes][3]
[How to define hidden global variables inside R Packages][4]
[Global variables in packages in r][5]
[Global variables in r][6]
[Global variable in a package which approach is more recommended][7]

  [1]: http://adv-r.had.co.nz/
  [2]: http://r-pkgs.had.co.nz/
  [3]: https://cran.r-project.org/web/packages/R6/vignettes/Introduction.html
  [4]: https://stackoverflow.com/questions/34254716/how-to-define-hidden-global-variables-inside-r-packages
  [5]: https://stackoverflow.com/questions/12598242/global-variables-in-packages-in-r
  [6]: https://stackoverflow.com/questions/1236620/global-variables-in-r
  [7]: https://stackoverflow.com/questions/28246952/global-variable-in-a-package-which-approach-is-more-recommended