plumber.R

#
# This is a Plumber API. You can run the API by clicking
# the 'Run API' button above.
#
# Find out more about building APIs with Plumber here:
#
#    https://www.rplumber.io/
#

library(plumber)

#* @apiTitle Plumber Swagger Experiments API

#* Log requests
#* @filter logger
function(req) {
  cat(as.character(Sys.time()), "-",
      req$REQUEST_METHOD, req$PATH_INFO, "-",
      req$HTTP_USER_AGENT, "@", req$REMOTE_ADDR, "\n")
  
  # Forward request
  forward()
}

#* Filter to practice preempt
#* @filter fail
function(req) {
  if (grepl("swagger", tolower(req$PATH_INFO))) {
    forward()
  }
  list(
    msg = "You didn't make it"
  )
}

#* Echo back the input
#* @preempt fail
#* @param msg The message to echo
#* @get /echo
function(msg = "") {
    list(msg = paste0("The message is: '", msg, "'"))
}

#* Plot a histogram
#* @preempt fail
#* @png
#* @get /plot
function() {
    rand <- rnorm(100)
    hist(rand)
}

#* Return the sum of two numbers
#* @preempt fail
#* @param a The first number to add
#* @param b The second number to add
#* @post /sum
function(a, b) {
    as.numeric(a) + as.numeric(b)
}