feat(textAreaInput): Add an autoresize option

NEWS.md

@@ -1,6 +1,14 @@
 # shiny (development version)
 
-## New features and improvements
+## New features
+
+* `textInput()`, `textAreaInput()`, `numericInput()` and `passwordInput()` all gain an `updateOn` option. `updateOn = "change"` is the default and previous behavior, where the input value updates immediately whenever the value changes. With `updateOn = "blur"`, the input value will update only when the text input loses focus or when the user presses Enter (or Cmd/Ctrl + Enter for `textAreaInput()`). (#4183)
+
+* `textAreaInput()` gains a `autoresize` option, which automatically resizes the text area to fit its content. (#4210)
+
+## Improvements
+
+* When auto-reload is enabled, Shiny now reloads the entire app when support files, like Shiny modules, additional script files, or web assets, change. To enable auto-reload, call `devmode(TRUE)` to enable Shiny's developer mode, or set `options(shiny.autoreload = TRUE)` to specifically enable auto-reload. You can choose which files are watched for changes with the `shiny.autoreload.pattern` option. (#4184)
 
 * When busy indicators are enabled (i.e., `useBusyIndicators()`), Shiny now:
     * Shows a spinner on recalculating htmlwidgets that have previously rendered an error (including `req()` and `validate()`). (#4172)
@@ -11,10 +19,6 @@
 
 * Shiny's Typescript assets are now compiled to ES2021 instead of ES5. (#4066)
 
-* `textInput()`, `textAreaInput()`, `numericInput()` and `passwordInput()` all gain an `updateOn` option. `updateOn = "change"` is the default and previous behavior, where the input value updates immediately whenever the value changes. With `updateOn = "blur"`, the input value will update only when the text input loses focus or when the user presses Enter (or Cmd/Ctrl + Enter for `textAreaInput()`). (#4183)
-
-* When auto-reload is enabled, Shiny now reloads the entire app when support files, like Shiny modules, additional script files, or web assets, change. To enable auto-reload, call `devmode(TRUE)` to enable Shiny's developer mode, or set `options(shiny.autoreload = TRUE)` to specifically enable auto-reload. You can choose which files are watched for changes with the `shiny.autoreload.pattern` option. (#4184)
-
 ## Bug fixes
 
 * Fixed a bug with modals where calling `removeModal()` too quickly after `showModal()` would fail to remove the modal if the remove modal message was received while the modal was in the process of being revealed. (#4173)

R/input-textarea.R

@@ -16,6 +16,8 @@
 #' @param resize Which directions the textarea box can be resized. Can be one of
 #'   `"both"`, `"none"`, `"vertical"`, and `"horizontal"`. The default, `NULL`,
 #'   will use the client browser's default setting for resizing textareas.
+#' @param autoresize If `TRUE`, the textarea will automatically resize to fit
+#'   the input text.
 #' @return A textarea input control that can be added to a UI definition.
 #'
 #' @family input elements
@@ -52,6 +54,7 @@ textAreaInput <- function(
   placeholder = NULL,
   resize = NULL,
   ...,
+  autoresize = FALSE,
   updateOn = c("change", "blur")
 ) {
   rlang::check_dots_empty()
@@ -63,22 +66,27 @@ textAreaInput <- function(
     resize <- match.arg(resize, c("both", "none", "vertical", "horizontal"))
   }
 
-  style <- css(
-    # The width is specified on the parent div.
-    width = if (!is.null(width)) "100%",
-    height = validateCssUnit(height),
-    resize = resize
-  )
+  classes <- "form-control"
+  if (autoresize) {
+    classes <- c(classes, "textarea-autoresize")
+    if (is.null(rows)) {
+      rows <- 1
+    }
+  }
 
   div(
-    class = "form-group shiny-input-container",
+    class = "shiny-input-textarea form-group shiny-input-container",
+    style = css(width = validateCssUnit(width)),
     shinyInputLabel(inputId, label),
-    style = if (!is.null(width)) paste0("width: ", validateCssUnit(width), ";"),
     tags$textarea(
       id = inputId,
-      class = "shiny-input-textarea form-control",
+      class = classes,
       placeholder = placeholder,
-      style = style,
+      style = css(
+        width = if (!is.null(width)) "100%",
+        height = validateCssUnit(height),
+        resize = resize
+      ),
       rows = rows,
       cols = cols,
       `data-update-on` = updateOn,