Add some basic print methods (#140)

Author: hadley

NEWS.md

@@ -1,5 +1,7 @@
 # chromote (development version)
 
+* `Chromote` and `ChromoteSession` gain print methods to give you a snapshot of the most important values.
+
 * `Chromote` gains a new `is_alive()` method equivalent to the old `is_active()` method; i.e. it reports on if there is an active chrome process running in the background.
 
 * Breaking change: `Chromote$is_active()` method now reports if there is an active connection to the underlying chrome instance, rather than whether or not that instance is alive (#94).

R/chromote.R

@@ -382,6 +382,35 @@ Chromote <- R6Class(
       invisible()
     },
 
+    #' @description Summarise the current state of the object.
+    #' @param verbose The print method defaults to a brief summary
+    #'   of the most important debugging info; use `verbose = TRUE` tp
+    #'   see the complex R6 object.
+    #' @param ... Passed on to `format()` when `verbose` = TRUE
+    print = function(..., verbose = FALSE) {
+      if (verbose) {
+        cat(format(self, ...), sep = "\n")
+      } else {
+        if (self$is_active()) {
+          state <- "active + alive"
+        } else if (self$is_alive()) {
+          state <- "alive"
+        } else {
+          state <- "closed"
+        }
+
+        ps <- self$get_browser()$get_process()
+
+        cat_line("<Chromote> (", state, ")")
+        if (self$is_alive()) {
+          cat_line("  URL:  ", self$url())
+          cat_line("  PID:  ", ps$get_pid())
+          cat_line("  Path: ", ps$get_cmdline()[[1]])
+        }
+      }
+      invisible(self)
+    },
+
     #' @field default_timeout Default timeout in seconds for \pkg{chromote} to
     #' wait for a Chrome DevTools Protocol response.
     default_timeout = 10,

R/chromote_session.R

@@ -544,7 +544,7 @@ ChromoteSession <- R6Class(
     #'   active debugging session?
     mark_closed = function(target_closed) {
       private$session_is_active <- FALSE
-      private$target_is_active <- target_closed
+      private$target_is_active <- !target_closed
     },
 
     #' @description Retrieve active status
@@ -577,6 +577,33 @@ ChromoteSession <- R6Class(
       private$init_promise_
     },
 
+    #' @description Summarise the current state of the object.
+    #' @param verbose The print method defaults to a brief summary
+    #'   of the most important debugging info; use `verbose = TRUE` tp
+    #'   see the complex R6 object.
+    #' @param ... Passed on to `format()` when `verbose` = TRUE
+    print = function(..., verbose = FALSE) {
+      if (verbose) {
+        cat(format(self, ...), sep = "\n")
+      } else {
+        if (self$is_active()) {
+          state <- "session + target active"
+        } else if (private$target_is_active) {
+          state <- "target active"
+        } else {
+          state <- "closed"
+        }
+
+        cat_line("<ChromoteSession> (", state, ")")
+        if (self$is_active())
+          cat_line("  Session ID: ", self$get_session_id())
+        if (private$target_is_active)
+          cat_line("  Target ID:  ", self$get_target_id())
+        cat_line("  Parent PID: ", self$parent$get_browser()$get_process()$get_pid())
+      }
+      invisible(self)
+    },
+
     #' @field parent [`Chromote`] object
     parent = NULL,
     #' @field default_timeout Default timeout in seconds for \pkg{chromote} to

R/utils.R

@@ -1,3 +1,7 @@
+cat_line <- function(...) {
+  cat(paste0(..., "\n", collapse = ""))
+}
+
 # =============================================================================
 # System
 # =============================================================================