Check that a chromote connection is alive

R/browser.R

@@ -23,6 +23,9 @@ Browser <- R6Class("Browser",
     #' @description Browser process
     get_process = function() private$process,
 
+    #' @description Is the process alive?
+    is_alive = function() private$process$is_alive(),
+
     #' @description Browser Host
     get_host = function() private$host,
 

R/chromote.R

@@ -174,6 +174,7 @@ Chromote <- R6Class(
     #'   `ChromoteSession` object. Otherwise, block during initialization, and
     #'   return a `ChromoteSession` object directly.
     new_session = function(width = 992, height = 1323, targetId = NULL, wait_ = TRUE) {
+      self$check_active()
       create_session(
         chromote = self,
         width = width,
@@ -213,9 +214,7 @@ Chromote <- R6Class(
     #' @param sessionId Determines which [`ChromoteSession`] with the
     #' corresponding to send the command to.
     send_command = function(msg, callback = NULL, error = NULL, timeout = NULL, sessionId = NULL) {
-      if (!private$is_active_) {
-        stop("Chromote object is closed.")
-      }
+      self$check_active()
 
       private$last_msg_id <- private$last_msg_id + 1
       msg$id <- private$last_msg_id
@@ -320,11 +319,41 @@ Chromote <- R6Class(
       paste0("http://", private$browser$get_host(), ":", private$browser$get_port(), path)
     },
 
-    #' @description Retrieve active status
-    #' Once initialized, the value returned is `TRUE`. If `$close()` has been
-    #' called, this value will be `FALSE`.
+    #' @description Is connection active? (i.e. is the websocket open?)
     is_active = function() {
-      private$is_active_
+      self$is_alive() && private$ws$readyState() %in% c(0L, 1L)
+    },
+
+    #' @description Is the underlying browser process alive?
+    is_alive = function() {
+      private$browser$is_alive()
+    },
+
+    #' @description Check that a chromote instance is active and alive,
+    #'  erroring if not.
+    check_active = function() {
+      if (!self$is_alive()) {
+        stop("Chromote has been closed.")
+      }
+
+      if (!self$is_active()) {
+        self$reactivate()
+      }
+    },
+
+    reactivate = function() {
+      inform(c(
+        "!" = "Reconnecting to chrome process.",
+        i = "All active sessions will be need to be respawned.")
+      )
+      self$connect()
+
+      # Mark all sessions as closed
+      for (session in private$sessions) {
+        session$mark_closed()
+      }
+      private$sessions <- list()
+      invisible(self)
     },
 
     #' @description Retrieve [`Browser`]` object
@@ -335,13 +364,14 @@ Chromote <- R6Class(
 
     #' @description Close the [`Browser`] object
     close = function() {
-      if (private$is_active_) {
+      if (self$is_active()) {
+        private$ws$close()
+      }
+      if (self$is_alive()) {
         self$Browser$close()
-        private$is_active_ <- FALSE
-        return(TRUE)
-      } else {
-        FALSE
       }
+
+      invisible()
     },
 
     #' @field default_timeout Default timeout in seconds for \pkg{chromote} to
@@ -400,9 +430,7 @@ Chromote <- R6Class(
     event_manager = NULL,
 
     register_event_listener = function(event, callback = NULL, timeout = NULL) {
-      if (!private$is_active_) {
-        stop("Chromote object is closed.")
-      }
+      self$check_active()
       private$event_manager$register_event_listener(event, callback, timeout)
     },
 
@@ -496,7 +524,7 @@ default_chromote_object <- function() {
 #' @rdname default_chromote_object
 #' @export
 has_default_chromote_object <- function() {
-  !is.null(globals$default_chromote) && globals$default_chromote$is_active()
+  !is.null(globals$default_chromote) && globals$default_chromote$is_alive()
 }
 
 #' @param x A \code{\link{Chromote}} object.

R/chromote_session.R

@@ -184,6 +184,10 @@ ChromoteSession <- R6Class(
     #' when the `ChromoteSession` is closed. Otherwise, block until the
     #' `ChromoteSession` has closed.
     close = function(wait_ = TRUE) {
+      if (!self$is_active()) {
+        return(invisible())
+      }
+
       # Even if this session calls Target.closeTarget, the response from
       # the browser is sent without a sessionId. In order to wait for the
       # correct browser response, we need to invoke this from the parent's
@@ -507,9 +511,7 @@ ChromoteSession <- R6Class(
     #' @param timeout Number of milliseconds for Chrome DevTools Protocol
     #' execute a method.
     send_command = function(msg, callback = NULL, error = NULL, timeout = NULL) {
-      if (!private$is_active_) {
-        stop("Session ", private$session_id, " is closed.")
-      }
+      self$check_active()
       self$parent$send_command(msg, callback, error, timeout, sessionId = private$session_id)
     },
 
@@ -547,7 +549,17 @@ ChromoteSession <- R6Class(
     #' Once initialized, the value returned is `TRUE`. If `$close()` has been
     #' called, this value will be `FALSE`.
     is_active = function() {
-      private$is_active_
+      private$is_active_ && self$parent$is_alive()
+    },
+
+    #' @description Check that a session is active, erroring if not.
+    check_active = function() {
+      if (!self$is_active()) {
+        abort(c(
+          paste("Session ", private$session_id, " has been closed."),
+          i = "Call session$respawn() to create a new session that connects to the same target."
+        ))
+      }
     },
 
     #' @description Initial promise
@@ -576,9 +588,7 @@ ChromoteSession <- R6Class(
     init_promise_ = NULL,
 
     register_event_listener = function(event, callback = NULL, timeout = NULL) {
-      if (!private$is_active_) {
-        stop("Session ", private$session_id, " is closed.")
-      }
+      self$check_active()
       private$event_manager$register_event_listener(event, callback, timeout)
     }
   )