R6- default value in subclass

Question

Exscuse my naive question, it is my first attempt on R6.

I want to create a subclass (Farmer) that inherits from Person, but has a default value for job.

I tried this, but it will not work:

Person <- R6Class("Person", list(
  name = NULL,
  job = NA,

  initialize = function(name, job = NA) {
    stopifnot(is.character(name), length(name) == 1)
    stopifnot(is.character(job), length(job) == 1)
    self$name <- name
    self$job <- job
  }
))

Farmer= R6Class("Farmer",
                inherit = Person,
                public = list(
                  job1=function(){
                    self$job= "farm"
                  }
                ))

Is it possible to set the default value, since I cannot use initialise on the subclass? Thank you!!

score 1 · Accepted Answer · answered Aug 20 '22 at 06:44

You can redefine the initialize method in your Farmer class. In this redefined method, you can call the initialize method from the super class (in your case Person) and set a default for job, while just passing all other arguments:

Farmer <- R6Class("Farmer", 
                  inherit = Person,
                  public = list(
                    initialize = function(...) {
                      super$initialize(
                        job = "farm",
                        ...
                      )
                    }
                  )
)

R6- default value in subclass

1 Answers1