R - 水管工，如何将值传递给全局环境？

Question

Can anyone tell me if there is a way to pass a value, say the session pid, to the global environment with a plumber API?

I have tried the <<- operator, but doesn't work.

here's a really simple example :

(my_file.R)

#* @param x My argument
#* @get /lag_lead 
function(x){
 return(x*2)
 api_pid <<- Sys.getpid()
}

and the script to run the api :

library(plumber)
mon_api <- plumb('my_file.R')
mon_api$run(port = 8000)

Answer 1

You are return -ing before the assignment, ie it does not take effect. Try

#* @param x My argument
#* @get /lag_lead 
function(x){
  api_pid <<- Sys.getpid()
  return(x*2)
}