Tidy plumber API

[blairj09]

First pass at a "tidy" API for the R6 methods used by plumber. Tests still need to be added, but wanted to get this initial approach out there.

PR task list:

• Update NEWS
• Add tests
• Update documentation with devtools::document()

[schloerke]

• Warning being produced

* checking Rd \usage sections ... WARNING
##[warning]Undocumented arguments in documentation object 'pr_handle'
  ‘serializer’

Undocumented arguments in documentation object 'pr_register_hook'
  ‘handlers’

[schloerke]

Final concern is over pr_new(). The name implies something that is only specific to R6. I understand the concept of where it came from. But it feels weird.

Ideas for a different name...

• plumb() (Allow for no file or directory information)
• pr_init()
• plumber() Can't double use the variable name. 😞
• plumbr() (Too close / confusing)
• pr()
• plmbr()

[meztez]

I like pr()

[schloerke]

Talked with @blairj09 . pr() it is! Has a nice auto complete pairing with pr_*()

[schloerke]

@blairj09 Can we also add:

pr_cookie <- function(
  pr,
  key,
  name = "plumber",
  expiration = FALSE,
  http = TRUE,
  secure = FALSE
) {
  pr$registerHooks(
    sessionCookie(key = key, name = name, expiration = expiration, http = http, secure = secure)
  )
  invisible(pr)
}

---

The tests look great!

[schloerke]

Have another addition (via @trestletech) from https://www.rplumber.io/articles/security.html#cross-origin-resource-sharing-cors

This one is also a similar situation to pr_cookie() in that it provides a clean / common interface.

(** Update)
Breaking a part the top comment here:

#' @filter cors
cors <- function(req, res) {
  
  res$setHeader("Access-Control-Allow-Origin", "*")
  
  if (req$REQUEST_METHOD == "OPTIONS") {
    res$setHeader("Access-Control-Allow-Methods","*")
    res$setHeader("Access-Control-Allow-Headers", req$HTTP_ACCESS_CONTROL_REQUEST_HEADERS)
    res$status <- 200 
    return(list())
  } else {
    plumber::forward()
  } 
}

into

pr_cors <- function(pr, origin, name = "cors") {
  pr_filter(pr, name, function(req, res) {
    res$setHeader("Access-Control-Allow-Origin", origin)
    forward()
  })
}
pr_options <- function(pr, methods = "*", name = "options") {
  pr_filter(pr, name, function(req) {
    if (req$REQUEST_METHOD == "OPTIONS") {
      res$setHeader("Access-Control-Allow-Methods","*")
      res$setHeader("Access-Control-Allow-Headers", req$HTTP_ACCESS_CONTROL_REQUEST_HEADERS)
      res$status <- 200 
      return(list())
    }
 
    plumber::forward()
  })
}