From 097d901191cb4f928d972b162bea3f4eebfbd48c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=A1bor=20Cs=C3=A1rdi?= <csardi.gabor@gmail.com>
Date: Tue, 23 Aug 2016 20:42:33 +0100
Subject: [PATCH] Updates can clear date and date range inputs

---
 NEWS                             |  3 +++
 R/update-input.R                 |  6 +++---
 man/updateDateInput.Rd           |  2 +-
 man/updateDateRangeInput.Rd      |  4 ++--
 srcjs/input_binding_date.js      |  6 ++++++
 srcjs/input_binding_daterange.js | 17 +++++++++++++----
 6 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/NEWS b/NEWS
index a269892bc..863358d32 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,9 @@ shiny 0.13.2.9005
 --------------------------------------------------------------------------------
 * Added support for bookmarkable state.
 
+* `updateDateInput()` and `updateDateRangeInput()` can now clear the date
+  input fields. (#1299, #896)
+
 * Added support for the `pool` package (use Shiny's timer/scheduler)
 
 * `Display: Showcase` now displays the .js, .html and .css files in the `www`
diff --git a/R/update-input.R b/R/update-input.R
index 9b153d069..ea42f3f21 100644
--- a/R/update-input.R
+++ b/R/update-input.R
@@ -166,7 +166,7 @@ updateActionButton <- function(session, inputId, label = NULL, icon = NULL) {
 #'
 #' @template update-input
 #' @param value The desired date value. Either a Date object, or a string in
-#'   \code{yyyy-mm-dd} format.
+#'   \code{yyyy-mm-dd} format. Supply \code{NA} to clear the date.
 #' @param min The minimum allowed date. Either a Date object, or a string in
 #'   \code{yyyy-mm-dd} format.
 #' @param max The maximum allowed date. Either a Date object, or a string in
@@ -226,9 +226,9 @@ updateDateInput <- function(session, inputId, label = NULL, value = NULL,
 #'
 #' @template update-input
 #' @param start The start date. Either a Date object, or a string in
-#'   \code{yyyy-mm-dd} format.
+#'   \code{yyyy-mm-dd} format. Supplying \code{NA} clears the start date.
 #' @param end The end date. Either a Date object, or a string in
-#'   \code{yyyy-mm-dd} format.
+#'   \code{yyyy-mm-dd} format. Supplying \code{NA} clears the end date.
 #' @param min The minimum allowed date. Either a Date object, or a string in
 #'   \code{yyyy-mm-dd} format.
 #' @param max The maximum allowed date. Either a Date object, or a string in
diff --git a/man/updateDateInput.Rd b/man/updateDateInput.Rd
index 436c9bd23..b8717f4a0 100644
--- a/man/updateDateInput.Rd
+++ b/man/updateDateInput.Rd
@@ -16,7 +16,7 @@ updateDateInput(session, inputId, label = NULL, value = NULL, min = NULL,
 \item{label}{The label to set for the input object.}
 
 \item{value}{The desired date value. Either a Date object, or a string in
-\code{yyyy-mm-dd} format.}
+\code{yyyy-mm-dd} format. Supply \code{NA} to clear the date.}
 
 \item{min}{The minimum allowed date. Either a Date object, or a string in
 \code{yyyy-mm-dd} format.}
diff --git a/man/updateDateRangeInput.Rd b/man/updateDateRangeInput.Rd
index 0560d51de..d39723ddd 100644
--- a/man/updateDateRangeInput.Rd
+++ b/man/updateDateRangeInput.Rd
@@ -16,10 +16,10 @@ updateDateRangeInput(session, inputId, label = NULL, start = NULL,
 \item{label}{The label to set for the input object.}
 
 \item{start}{The start date. Either a Date object, or a string in
-\code{yyyy-mm-dd} format.}
+\code{yyyy-mm-dd} format. Supplying \code{NA} clears the start date.}
 
 \item{end}{The end date. Either a Date object, or a string in
-\code{yyyy-mm-dd} format.}
+\code{yyyy-mm-dd} format. Supplying \code{NA} clears the end date.}
 
 \item{min}{The minimum allowed date. Either a Date object, or a string in
 \code{yyyy-mm-dd} format.}
diff --git a/srcjs/input_binding_date.js b/srcjs/input_binding_date.js
index d731d6510..edb1228b4 100644
--- a/srcjs/input_binding_date.js
+++ b/srcjs/input_binding_date.js
@@ -14,6 +14,12 @@ $.extend(dateInputBinding, {
   },
   // value must be an unambiguous string like '2001-01-01', or a Date object.
   setValue: function(el, value) {
+    // R's NA, which is null here will remove current value
+    if (value === null) {
+      $(el).find('input').val('').datepicker('update');
+      return;
+    }
+
     var date = this._newDate(value);
     // If date is invalid, do nothing
     if (isNaN(date))
diff --git a/srcjs/input_binding_daterange.js b/srcjs/input_binding_daterange.js
index 8d8e41fe9..317247cd3 100644
--- a/srcjs/input_binding_daterange.js
+++ b/srcjs/input_binding_daterange.js
@@ -23,13 +23,22 @@ $.extend(dateRangeInputBinding, dateInputBinding, {
     var $inputs = $(el).find('input');
 
     // If value is undefined, don't try to set
+    // null will remove the current value
     if (value[0] !== undefined) {
-      var start = this._newDate(value[0]);
-      $inputs.eq(0).datepicker('update', start);
+      if (value[0] === null) {
+        $inputs.eq(0).val('').datepicker('update');
+      } else {
+        var start = this._newDate(value[0]);
+        $inputs.eq(0).datepicker('update', start);
+      }
     }
     if (value[1] !== undefined) {
-      var end = this._newDate(value[1]);
-      $inputs.eq(1).datepicker('update', end);
+      if (value[1] === null) {
+        $inputs.eq(1).val('').datepicker('update');
+      } else {
+        var end = this._newDate(value[1]);
+        $inputs.eq(1).datepicker('update', end);
+      }
     }
   },
   getState: function(el) {