I'm creating an active binding in an R6 class to print a private element.
When I'm calling print(private$privMail), the result is printed twice but only on private elements, not on public.
If I'm not using print, no problem.
Here's a reprex :
team <- R6::R6Class("Team",
public = list( mail = "colin@thinkr.fr"),
private = list(privMail = "colin@thinkr.fr"),
active = list(
MailPriv = function(){ print(private$privMail) },
Mail = function(){ print(self$mail) }
)
)
a <- team$new()
a$MailPriv
#> [1] "colin@thinkr.fr"
#> [1] "colin@thinkr.fr"
a$Mail
#> [1] "colin@thinkr.fr"
#> [1] "colin@thinkr.fr"
#Without using print
team2 <- R6::R6Class("Team",
public = list( mail = "colin@thinkr.fr"),
private = list(privMail = "colin@thinkr.fr"),
active = list(
MailPriv = function(){ private$privMail },
Mail = function(){self$mail }
)
)
abis <- team2$new()
abis$MailPriv
#> [1] "colin@thinkr.fr"
abis$Mail
#> [1] "colin@thinkr.fr"
devtools::session_info()
#> Session info -------------------------------------------------------------
#> setting value
#> version R version 3.4.4 (2018-03-15)
#> system x86_64, darwin15.6.0
#> ui X11
#> language (EN)
#> collate fr_FR.UTF-8
#> tz Europe/Paris
#> date 2018-05-24
#> Packages -----------------------------------------------------------------
#> package * version date source
#> backports 1.1.2 2017-12-13 CRAN (R 3.4.3)
#> base * 3.4.4 2018-03-15 local
#> compiler 3.4.4 2018-03-15 local
#> datasets * 3.4.4 2018-03-15 local
#> devtools 1.13.5 2018-02-18 CRAN (R 3.4.3)
#> digest 0.6.15 2018-01-28 CRAN (R 3.4.3)
#> evaluate 0.10.1 2017-06-24 CRAN (R 3.4.1)
#> graphics * 3.4.4 2018-03-15 local
#> grDevices * 3.4.4 2018-03-15 local
#> htmltools 0.3.6 2017-04-28 CRAN (R 3.4.0)
#> knitr 1.20 2018-02-20 CRAN (R 3.4.3)
#> magrittr 1.5 2014-11-22 CRAN (R 3.4.0)
#> memoise 1.1.0 2017-04-21 CRAN (R 3.4.0)
#> methods * 3.4.4 2018-03-15 local
#> R6 2.2.2 2017-06-17 CRAN (R 3.4.0)
#> Rcpp 0.12.16 2018-03-13 CRAN (R 3.4.4)
#> rmarkdown 1.9 2018-03-01 CRAN (R 3.4.3)
#> rprojroot 1.3-2 2018-01-03 CRAN (R 3.4.3)
#> stats * 3.4.4 2018-03-15 local
#> stringi 1.1.7 2018-03-12 CRAN (R 3.4.4)
#> stringr 1.3.0 2018-02-19 CRAN (R 3.4.3)
#> tools 3.4.4 2018-03-15 local
#> utils * 3.4.4 2018-03-15 local
#> withr 2.1.2 2018-04-13 Github (jimhester/withr@79d7b0d)
#> yaml 2.1.18 2018-03-08 CRAN (R 3.4.4)
To be precise, my question is not about how to solve this issue (I can do it by removing the print, as it is done in the second class), but about why using print() print twice the content.
I'm not sure I understood perfectly your question, but I think that you have one print from the print and one from the returned element of the print.
Try e.g. (print(1)).
So, basically, I would remove the print here.