Add placeholder parameter to updateTextInput (#1742)

* add placeholder parameter

* add js placeholder code

* roxygenize

* grunt

* fix updateCheckBoxInput not to use placeholder

* simply roxygen

* add NEWS

* revert grunt

NEWS.md

@@ -15,6 +15,8 @@ shiny 1.0.3.9000
 
 * For `conditionalPanel`s, Shiny now gives more informative messages if there are errors evaluating or parsing the JavaScript conditional expression. ([#1727](https://github.com/rstudio/shiny/pull/1727))
 
+* Addressed [#1738](https://github.com/rstudio/shiny/issues/1738): The `updateTextInput` and `updateTextAreaInput` functions can now update the placeholder. ([#1742](https://github.com/rstudio/shiny/pull/1742))
+
 ### Bug fixes
 
 * Fixed [#1546](https://github.com/rstudio/shiny/issues/1546): make it possible (without any hacks) to write arbitrary data into a module's `session$userData` (which is exactly the same environment as the parent's `session$userData`). To be clear, it allows something like `session$userData$x <- TRUE`, but not something like `session$userData <- TRUE` (that is not allowed in any context, whether you're in the main app, or in a module) ([#1732](https://github.com/rstudio/shiny/pull/1732)).

R/update-input.R

@@ -2,6 +2,7 @@
 #'
 #' @template update-input
 #' @param value The value to set for the input object.
+#' @param placeholder The placeholder to set for the input object.
 #'
 #' @seealso \code{\link{textInput}}
 #'
@@ -34,15 +35,15 @@
 #' shinyApp(ui, server)
 #' }
 #' @export
-updateTextInput <- function(session, inputId, label = NULL, value = NULL) {
-  message <- dropNulls(list(label=label, value=value))
+updateTextInput <- function(session, inputId, label = NULL, value = NULL, placeholder = NULL) {
+  message <- dropNulls(list(label=label, value=value, placeholder=placeholder))
   session$sendInputMessage(inputId, message)
 }
 
 #' Change the value of a textarea input on the client
 #'
 #' @template update-input
-#' @param value The value to set for the input object.
+#' @inheritParams updateTextInput
 #'
 #' @seealso \code{\link{textAreaInput}}
 #'
@@ -106,7 +107,10 @@ updateTextAreaInput <- updateTextInput
 #' shinyApp(ui, server)
 #' }
 #' @export
-updateCheckboxInput <- updateTextInput
+updateCheckboxInput <- function(session, inputId, label = NULL, value = NULL) {
+  message <- dropNulls(list(label=label, value=value))
+  session$sendInputMessage(inputId, message)
+}
 
 
 #' Change the label or icon of an action button on the client

man/updateTextAreaInput.Rd

@@ -4,7 +4,8 @@
 \alias{updateTextAreaInput}
 \title{Change the value of a textarea input on the client}
 \usage{
-updateTextAreaInput(session, inputId, label = NULL, value = NULL)
+updateTextAreaInput(session, inputId, label = NULL, value = NULL,
+  placeholder = NULL)
 }
 \arguments{
 \item{session}{The \code{session} object passed to function given to
@@ -15,6 +16,8 @@ updateTextAreaInput(session, inputId, label = NULL, value = NULL)
 \item{label}{The label to set for the input object.}
 
 \item{value}{The value to set for the input object.}
+
+\item{placeholder}{The placeholder to set for the input object.}
 }
 \description{
 Change the value of a textarea input on the client

man/updateTextInput.Rd

@@ -4,7 +4,8 @@
 \alias{updateTextInput}
 \title{Change the value of a text input on the client}
 \usage{
-updateTextInput(session, inputId, label = NULL, value = NULL)
+updateTextInput(session, inputId, label = NULL, value = NULL,
+  placeholder = NULL)
 }
 \arguments{
 \item{session}{The \code{session} object passed to function given to
@@ -15,6 +16,8 @@ updateTextInput(session, inputId, label = NULL, value = NULL)
 \item{label}{The label to set for the input object.}
 
 \item{value}{The value to set for the input object.}
+
+\item{placeholder}{The placeholder to set for the input object.}
 }
 \description{
 Change the value of a text input on the client

srcjs/input_binding_text.js

@@ -30,12 +30,16 @@ $.extend(textInputBinding, {
     if (data.hasOwnProperty('label'))
       $(el).parent().find('label[for="' + $escape(el.id) + '"]').text(data.label);
 
+    if (data.hasOwnProperty('placeholder'))
+      el.placeholder = data.placeholder;
+
     $(el).trigger('change');
   },
   getState: function(el) {
     return {
       label: $(el).parent().find('label[for="' + $escape(el.id) + '"]').text(),
-      value: el.value
+      value: el.value,
+      placeholder: el.placeholder
     };
   },
   getRatePolicy: function() {