add an explicit label argument to animation_button(), fixes #1205

Author: cpsievert

NEWS.md

@@ -5,6 +5,7 @@
 * Upgraded to plotly.js v1.34.0. A _huge_ amount of features and improvements have been made since v1.29.2 (i.e., the version included in the last CRAN release of the R package - v4.7.1). Highlights include a complete re-write of `scattergl` to make it nearly feature complete with `scatter`, localization of text rendering (i.e., international translations), and two new trace types (`violin` & `table`). Read more about the v1.32.0 release [here](https://codeburst.io/notes-from-the-latest-plotly-js-release-b035a5b43e21) and the complete list of changes [here](https://github.com/plotly/plotly.js/releases).
 * The selection mode can now switch from 'transient' to 'persistent' by holding the 'shift' key. It's still possible to _force_ persistent selection by setting `persistent = TRUE` in `highlight()`, but `persistent = FALSE` (the default) is now recommended since it allows one to switch between [persistent/transient selection](https://plotly-book.cpsievert.me/linking-views-without-shiny.html#transient-versus-persistent-selection) in the browser, rather than at the command line.
 * Instead of an error, `ggplotly(NULL, "message")` and `plotly_build(NULL, "message")` now returns `htmltools::div("message")`, making it easier to relay messages in shiny when data isn't yet ready to plot (see #1116)
+* The `animation_button()` function gains a `label` argument, making it easier to control the label of an animation button generated through the `frame` API (see #1205).
 
 ## CHANGES
 

R/animate.R

@@ -150,12 +150,16 @@ animation_slider <- function(p, hide = FALSE, ...) {
 
 
 #' @inheritParams animation_slider
+#' @param label a character string used for the animation button's label
 #' @export
 #' @rdname animation
-animation_button <- function(p, ...) {
+animation_button <- function(p, ..., label) {
 
   p <- plotly_build(p)
   isAniButton <- vapply(p$x$layout$updatemenus, is_ani_button, logical(1))
+  if (!missing(label)) {
+    p$x$layout$updatemenus[[which(isAniButton)]]$buttons[[1]]$label <- label
+  }
   p$x$layout$updatemenus[[which(isAniButton)]] <- modify_list(
     p$x$layout$updatemenus[[which(isAniButton)]], list(...)
   )

man/animation.Rd

@@ -315,4 +315,15 @@ test_that("animation frames are boxed up correctly", {
 
 })
 
-
+test_that("animation button can be customized", {
+  
+  p <- plot_ly(mtcars, x = ~mpg, y = ~wt, frame = ~vs) %>% 
+    animation_button(label = "Custom", bgcolor = "red", font = list(color = "white"))
+  
+  f <- plotly_build(p)$x
+  
+  menu <- f$layout$updatemenus[[1]]
+  expect_true(menu$bgcolor == "red")
+  expect_true(menu$font$color == "white")
+  expect_true(menu$buttons[[1]]$label == "Custom")
+})