Allow enable() and disable() methods to be used when auto_events is TRUE

NEWS.md

@@ -1,5 +1,8 @@
 # chromote (development version)
 
+* chromote sessions allow you to call `enable()` methods manually event when
+  `auto_events` is `FALSE`. If an `enable()` method is called, chromote will
+  not call it again automatically, until you manually `disable()` it (#144).
 # chromote 0.2.0
 
 ## Breaking changes

R/chromote_session.R

@@ -626,6 +626,14 @@ ChromoteSession <- R6Class(
     register_event_listener = function(event, callback = NULL, timeout = NULL) {
       self$check_active()
       private$event_manager$register_event_listener(event, callback, timeout)
+    },
+
+    manually_enable = function(domain) {
+      private$event_manager$manually_enable(domain)
+    },
+
+    manually_disable = function(domain) {
+      private$event_manager$manually_disable(domain)
     }
   )
 )

R/event_manager.R

@@ -13,6 +13,9 @@ EventManager <- R6Class("EventManager",
         is.function(domain$enable)
       })
 
+      private$manually_enabled <- rep(FALSE, length(session$protocol))
+      names(private$manually_enabled) <- names(session$protocol)
+
       private$event_callbacks <- fastmap()
     },
 
@@ -44,6 +47,15 @@ EventManager <- R6Class("EventManager",
       p
     },
 
+
+    manually_enable = function(domain) {
+      private$manually_enabled[[domain]] <- TRUE
+    },
+
+    manually_disable = function(domain) {
+      private$manually_enabled[[domain]] <- FALSE
+    },
+
     invoke_event_callbacks = function(event, params) {
       callbacks <- private$event_callbacks$get(event)
       if (is.null(callbacks) || callbacks$size() == 0)
@@ -58,11 +70,13 @@ EventManager <- R6Class("EventManager",
       private$event_callbacks$remove(event)
     }
   ),
-
   private = list(
     # The ChromoteSession or Chromote object that owns this EventManager.
     session = NULL,
     event_callbacks = NULL,
+    # Keeps track of whether a domain is manually enabled or not. If it is, we opt out of
+    # auto events.
+    manually_enabled = NULL,
     # For keeping count of the number of callbacks for each domain; if
     # auto_events is TRUE, then when the count goes from 0 to 1 or 1 to 0 for
     # a given domain, it will automatically enable or disable events for that
@@ -124,10 +138,13 @@ EventManager <- R6Class("EventManager",
       # method.)
       if (private$session$get_auto_events() &&
           private$event_callback_counts[[domain]] == 1 &&
-          isTRUE(private$event_enable_domains[[domain]]))
+          isTRUE(private$event_enable_domains[[domain]]) &&
+          !isTRUE(private$manually_enabled[[domain]]))
       {
         private$session$debug_log("Enabling events for ", domain)
         private$session[[domain]]$enable()
+        # We are not manually enabling this domain, so make sure that this continues to be FALSE.
+        private$manually_enabled[[domain]] <- FALSE
       }
 
       invisible(private$event_callback_counts[[domain]])
@@ -141,7 +158,8 @@ EventManager <- R6Class("EventManager",
       # enable events for this domain.
       if (private$session$get_auto_events() &&
           private$event_callback_counts[[domain]] == 0 &&
-          isTRUE(private$event_enable_domains[[domain]]))
+          isTRUE(private$event_enable_domains[[domain]]) &&
+          !isTRUE(private$manually_enabled[[domain]]))
       {
         private$session$debug_log("Disabling events for ", domain)
         private$session[[domain]]$disable()

R/protocol.R

@@ -43,7 +43,7 @@ get_items <- function(domain, type = c("commands", "events")) {
 command_to_function <- function(command, domain_name, env) {
   new_function(
     args = gen_command_args(command$parameters),
-    body = gen_command_body(paste0(domain_name, ".", command$name), command$parameters),
+    body = gen_command_body(domain_name, command$name, command$parameters),
     env  = env
   )
   # TODO:
@@ -79,7 +79,8 @@ gen_command_args <- function(params) {
 
 # Returns a function body for a command.
 # method_name is something like "Browser.getVersion"
-gen_command_body <- function(method_name, params) {
+gen_command_body <- function(domain_name, command_name, params) {
+  method_name <- paste0(domain_name, ".", command_name)
 
   # Construct expressions for checking missing args
   required_params <- params[!fetch_key_l(params, "optional", default = FALSE)]
@@ -105,6 +106,15 @@ gen_command_body <- function(method_name, params) {
       expr({})
     }
 
+  # If a domain is manualy enabled or disabled, opt out of auto events for that domain
+  enable_event_expr <- if (identical(command_name, "enable")) {
+    expr({private$manually_enable(!!domain_name)})
+  } else if (identical(command_name, "disable")) {
+    expr({private$manually_disable(!!domain_name)})
+  } else {
+    expr({})
+  }
+
   # Construct parameters for message
   param_list <- lapply(params, function(param) {
     as.symbol(param$name)
@@ -125,6 +135,7 @@ gen_command_body <- function(method_name, params) {
     if (!identical(wait_, TRUE) && !identical(wait_, FALSE))
       stop("`wait_` must be TRUE or FALSE.")
 
+    !!!enable_event_expr
 
     # Check for missing non-optional args
     !!!check_missing_exprs

README.Rmd

@@ -1070,13 +1070,9 @@ Currently setting custom headers requires a little extra work because it require
 
 ```R
 b <- ChromoteSession$new()
-# Currently need to manually enable Network domain notifications. Calling
-# b$Network$enable() would do it, but calling it directly will bypass the
-# callback counting and the notifications could get automatically disabled by a
-# different Network event. We'll enable notifications for the Network domain by
-# listening for a particular event. We'll also store a callback that will
-# decrement the callback counter, so that we can disable notifications ater.
-disable_network_notifications <- b$Network$responseReceived(function (msg) NULL)
+# Currently need to manually enable Network domain notifications.
+b$Network$enable()
+
 b$Network$setExtraHTTPHeaders(headers = list(
   foo = "bar",
   header1 = "value1"
@@ -1097,9 +1093,8 @@ b$Page$navigate("http://scooterlabs.com/echo")
 b$screenshot(show = TRUE)
 
 
-# Disable extra headers entirely, by decrementing Network callback counter,
-# which will disable Network notifications.
-disable_network_notifications()
+# Disable extra headers entirely, by disabling Network notifications.
+b$Network$disable()
 ```
 
 ### Custom User-Agent