selectize.js default behavior: remove label and allow for placeholder

I would like to create an R Markdown document with > 1 plotly figure where points can be highlighted with the selectize.js widget. Here a reproducible example

---
title: Test
output: html_document
---

# wt vs mpg

```{r, message=FALSE, warning=FALSE}
library(plotly)
myData <- highlight_key(mtcars, ~rownames(mtcars))
myFig <- plot_ly(myData, x = ~wt, y = ~mpg) 
highlight(myFig, selectize = TRUE)
```

# disp vs mpg

```{r, message=FALSE}
myData <- highlight_key(mtcars, ~rownames(mtcars))
myFig <- plot_ly(myData, x = ~disp, y = ~mpg) 
highlight(myFig, selectize = TRUE)
```

Two Design improvements would be nice

1. No label above selectize widget
2. Placeholder text in the <input> field of the widget

For the first problem I found a workaround using highlight_key(..., group = " "). However I need to define for each plot a new "invisible" group identifier otherwise the highlighting of the plots will be linked (i.e. if I highlight a car in one plot it will be highlighted in all plots). At the moment I use group = " ", group = " ", group = " ", and so on but this is stupid.

A workaround for the placeholder text was already described on Stack Overflow. But it does not work out of the box if there are multiple plotly figures in one R Markdown document.

Optimal solution would be to have two additional arguments in the highlight() function

• label = NULL makes sure that no label is plotted
• placeholder = "" to define the placeholder in the selectize box.

Let me know what you think of it : )

Bắt đầu với điểm vào highlight() của R và hành vi của selectize.js được thực thi bởi bản tái hiện R Markdown được cung cấp. Xác minh cách nhiều biểu đồ plotly chia sẻ trạng thái lựa chọn, sau đó cho phép cấu hình việc ẩn nhãn và văn bản placeholder, đồng thời vẫn giữ các lựa chọn độc lập giữa các biểu đồ.