helpers

NAMESPACE

@@ -13,9 +13,13 @@ export(gep_render_har)
 export(gep_render_html)
 export(gep_render_magick)
 export(gep_render_pdf)
+export(gep_stop)
 export(gepetto)
 export(get_chrome_env)
+export(install_gepetto)
 export(set_chrome_env)
+export(start_gepetto)
+export(stop_gepetto)
 import(httr)
 import(magick)
 import(processx)

R/gepetto-helpers.R

@@ -0,0 +1,141 @@
+#' Install gepetto
+#'
+#' This function verifies you have what you need to install `gepetto` then
+#' does so (globally). Ideally, you'll have `Node.js` and `npm` already on your
+#' system (since this function will not install them).
+#'
+#' While you _can_ try to install gepetto this way, it is highly recommended that
+#' you follow the instructions (<https://gitlab.com/hrbrmstr/gepetto>) manually
+#' since many Node.js/npm installations have permissions issues due to errant
+#' historical use of `sudo`.
+#'
+#' @md
+#' @export
+install_gepetto <- function() {
+
+  node <- Sys.which("node")
+  npm <- Sys.which("npm")
+
+  if (node == "") {
+    message(
+      "Could not locate Node.js. Please visit <https://nodejs.org/en/download/package-manager/> ",
+      "and obtain it via one of the methods described there then try installing gepetto from ",
+      "a fresh R session.", sep=""
+    )
+    return()
+  }
+
+  if (npm == "") {
+    message(
+      "Could not local npm. Please visit <https://www.npmjs.com/get-npm> to ensure ",
+      "you have installed both Node.js and npm correctly, then try installing gepetto ",
+      "from a fresh R session.", sep=""
+    )
+    return()
+  }
+
+  res <- processx::run(node, "--version", error_on_status = FALSE)
+  if (res$status != 0) {
+    message(
+      "An error occurred while trying to determine the version of Node.js that is ",
+      "installed on the system. Please ensure you have it installed correctly and ",
+      "try installing gepetto again from a fresh R session.", sep=""
+    )
+    return()
+  }
+
+  node_vers <- unlist(strsplit(res$stdout, "\\."))[1]
+  if (!(node_vers %in% c("v10", "v9"))) {
+    message(
+      "You have a very old installation of Node.js. Please update it and try installing ",
+      "gepetto again from a fresh R session.", sep=""
+    )
+    return()
+  }
+
+  res <- processx::run(npm, "--version", error_on_status = FALSE)
+  if (res$status != 0) {
+    message(
+      "An error occurred while trying to determine the version of npm that is ",
+      "installed on the system. Please ensure you have it installed correctly and ",
+      "try installing gepetto again from a fresh R session.", sep=""
+    )
+    return()
+  }
+
+  npm_vers <- unlist(strsplit(res$stdout, "\\."))[1]
+  if (!(npm_vers %in% c("6"))) {
+    message(
+      "You have an old installation of npm. Please update it and try installing ",
+      "gepetto again from a fresh R session.", sep=""
+    )
+    return()
+  }
+
+  message("Attemping to install gepetto")
+
+  processx::run(
+    command = "npm",
+    args =  c("install", "https://gitlab.com/hrbrmstr/gepetto.git", "--global"),
+    error_on_status = FALSE,
+    echo_cmd = TRUE,
+    echo = TRUE
+  ) -> res
+
+  if (res$status == 0) {
+    message("gepetto has been installed.")
+  } else {
+    message(
+      "There was an error installing gepetto. Check the error log and make sure ",
+      "permissions are set correctly or for other errors that occurred which ",
+      "prevented the installation frombeing successful and try again or follow the ",
+      "manual instructions at <https://gitlab.com/hrbrmstr/gepetto>.", sep=""
+    )
+  }
+
+}
+
+#' Start/stop gepetto
+#'
+#' These functions can help start/stop gepetto instances. You must remember to
+#' save the object returned by [start_gepetto()].
+#'
+#' Note that [stop_gepetto()] kills the process. You can/should consider using
+#' [gep_stop()] instead.
+#'
+#' @md
+#' @param host IP/host to use instead of `localhost`
+#' @param port port to use besides the default (`8080`)
+#' @param pxobj the `processx` object of a running gepetto instance generated by [start_gepetto()]
+#' @return [start_gepetto()] returns a `processx` object
+#' @export
+#' @examples \dontrun{
+#' pid <- start_gepetto()
+#' # ... do stuff
+#' stop_gepetto(pid)
+#' }
+start_gepetto <- function(host = "localhost", port = 8080) {
+
+  gep <- Sys.which("gepetto")
+  if (gep == "") stop("gepetto not found.", call.=FALSE)
+
+  HOST <- Sys.getenv("HOST")
+  on.exit(Sys.setenv(HOST=HOST), add=TRUE)
+  PORT <- Sys.getenv("PORT")
+  on.exit(Sys.setenv(PORT=PORT), add=TRUE)
+
+  Sys.setenv(HOST=host)
+  Sys.setenv(PORT=port)
+  processx::process$new(
+    command = "gepetto", stdout = "|", stderr = "|"
+  ) -> res
+
+  res
+
+}
+
+#' @rdname start_gepetto
+#' @export
+stop_gepetto <- function(pxobj) {
+  pxobj$kill()
+}

R/gepetto.R

@@ -245,6 +245,31 @@ gep_active <- function(gep) {
 
 }
 
+#' Gracefully stop a gepetto instance
+#'
+#' @md
+#' @param gep a gepetto connection object
+#' @export
+#' @examples \dontrun{
+#' gepetto() %>%
+#'   gep_stop()
+#' }
+gep_stop <- function(gep) {
+
+  s_GET(
+    url = sprintf("http://%s:%s/_stop", gep$host, gep$port)
+  ) -> res
+
+  res <- stop_for_problem(res)
+
+  httr::stop_for_status(res)
+
+  out <- httr::content(res, as="text")
+  out <- jsonlite::fromJSON(out)
+
+  out$status == "ok"
+
+}
 
 #' #' Execute Puppeteer commands
 #' #'

README.Rmd

@@ -74,6 +74,14 @@ The following functions are implemented:
 
 ### `gepetto`-based ops
 
+Helpers to get gepetto installed:
+
+- `install_gepetto`:	Install gepetto
+- `start_gepetto`:	Start/stop gepetto
+- `stop_gepetto`:	Start/stop gepetto
+
+API interface functions:
+
 - `gepetto`:	Create a connection to a Gepetto API server
 - `gep_active`:	Get test whether the gepetto server is active
 - `gep_debug`:	Get "debug-level" information of a running gepetto server

README.md

@@ -75,6 +75,14 @@ The following functions are implemented:
 
 ### `gepetto`-based ops
 
+Helpers to get gepetto installed:
+
+- `install_gepetto`:	Install gepetto
+- `start_gepetto`:	Start/stop gepetto
+- `stop_gepetto`:	Start/stop gepetto
+
+API interface functions:
+
 - `gepetto`:	Create a connection to a Gepetto API server
 - `gep_active`:	Get test whether the gepetto server is active
 - `gep_debug`:	Get "debug-level" information of a running gepetto server