Use 'getDefaultReactiveDomain()' when there is no 'session' argument …

…provided to 'shinyURL.server()'

DESCRIPTION

@@ -1,12 +1,12 @@
 Package: shinyURL
 Type: Package
 Title: Save and restore the state of Shiny apps
-Version: 0.0.22
+Version: 0.0.23
 Encoding: UTF-8
 Author: Andrzej Oleś
 Maintainer: Andrzej Oleś <[email protected]>
-Description: Save and restore the state of a Shiny app's widgets by encoding
-    them in an URL query string.
+Description: Save and restore the view state of a Shiny app by encoding the
+  values of user inputs and active tab panels in the app's URL query string.
 Imports:
     RCurl,
     shiny (>= 0.12.0),

NAMESPACE

@@ -8,6 +8,7 @@ importFrom(RCurl,getURL)
 importFrom(shiny,actionButton)
 importFrom(shiny,div)
 importFrom(shiny,eventReactive)
+importFrom(shiny,getDefaultReactiveDomain)
 importFrom(shiny,icon)
 importFrom(shiny,includeScript)
 importFrom(shiny,invalidateLater)

R/shinyURL.R

@@ -1,13 +1,13 @@
 #' Save and restore the state of Shiny app's widgets
 #' 
-#' Encode the state of Shiny app's widgets into an URL query string, and use
+#' Encode the state of Shiny app's widgets into an URL query string, and use 
 #' parameters from the URL query string to initialize the applications.
 #' 
 #' @section Quick setup: To start using shinyURL in your Shiny app, follow these
-#'   three steps: \enumerate{ \item Load the package in both 'server.R' an
-#'   'ui.R': \code{library("shinyURL")} \item Add a call to \code{
+#'   three steps: \enumerate{ \item Load the package in both 'server.R' an 
+#'   'ui.R': \code{library("shinyURL")} \item Add a call to \code{ 
 #'   shinyURL.server(session)} inside the 'shinyServer' function in 'server.R', 
-#'   where `session` is the argument passed to the server function. \item Add
+#'   where `session` is the argument passed to the server function. \item Add 
 #'   the \code{shinyURL.ui()} widget to 'ui.R'. }
 #' @author Andrzej Oleś <andrzej.oles@@embl.de>
 #' @examples
@@ -47,9 +47,11 @@
 #' 
 #' } 
 #' @name shinyURL
-#' @importFrom shiny isolate observe parseQueryString observeEvent
+#' @importFrom shiny isolate observe parseQueryString observeEvent 
 #'   updateTextInput eventReactive reactiveValuesToList invalidateLater
-#' @importFrom shiny tagList tags icon includeScript actionButton div validateCssUnit
+#'   getDefaultReactiveDomain
+#' @importFrom shiny tagList tags icon includeScript actionButton div
+#'   validateCssUnit
 #' @importFrom RCurl getURL
 #' @importFrom utils URLencode
 NULL
@@ -59,10 +61,14 @@ inputId=".shinyURL"
 #' @details The \code{shinyURL.server} method contains server logic for encoding
 #'   and restoring the widgets' state. It is called from inside the app's server
 #'   function with the \code{session} argument.
-#' @param session Parameter passed from the Shiny server function
+#'   ).
+#' @param session typically the same as the optional parameter passed into the Shiny server function as an argument; if missing defaults to \code{getDefaultReactiveDomain()}
 #' @rdname shinyURL
 #' @export
 shinyURL.server = function(session) {
+  if (missing(session))
+    session = getDefaultReactiveDomain()
+
   queryValues <- isolate(parseQueryString(session$clientData$url_search, nested=TRUE))
 
   ## initialize from query string

README.md

@@ -7,24 +7,28 @@
 
 ## Use
 
-1. Load the package in both **server.R** and **ui.R**:
+1. Load the package in both **server.R** and **ui.R**.
 
         library("shinyURL")
 
-2. In **server.R**, add a call to
+2. In **server.R**, add inside the server function a call to
 
-        shinyURL.server(session)
+        shinyURL.server()
 
-    inside the `shinyServer` function, where `session` is the argument passed to the server function.
+    where `session` is the argument passed to the server function.
 
-3. Add the shinyURL widget to **ui.R**:
+3. Add the shinyURL widget to **ui.R**.
 
         shinyURL.ui()
         
-## Restoring tabset and navbar panels
+### Restoring of tabset and navbar panels
 
 To save and restore active tabs provide the `id` argument to the functions `tabsetPanel` or `navbarPage`.
 
+### Disable encoding of certain inputs
+
+You can suppress certain inputs from being encoded in the query URL by using IDs with a leading dot, e.g. `.inputName`. These inputs won't be restored.
+
 ## Limitations
 
 ### Long URLs
@@ -47,6 +51,3 @@ These points are especially relevant for apps with lots of controls.
 
 Unfortunately, operations performed using action buttons cannot be reliably recorded and restored. 
 
-### Disable encoding of certain inputs
-
-You can suppress certain inputs from being encoded in the query URL by using IDs with a leading dot, e.g. `.inputName`. These inputs won't be restored.