R 串扰：如何在 filter_slider() 中设置默认值以过滤日期列

Question

我的问题类似于这个问题，询问如何在

crosstalk::filter_select

中设置默认过滤器选择。但是，我需要对日期列的

R

进行默认选择。我创建了一个可重现的示例，其中包含虚拟数据、过滤器和

分类过滤器

的工作默认选择。我希望能够对 date slider 做类似的事情。我应该如何更改我的 JavaScript，以便选择明天和后天之间的日期范围？ crosstalk::filter_slider

Answer 1

library(crosstalk)
library(htmltools)

# dummy data
dat <- data.frame(
  date = Sys.Date() + 0:4,
  letter = letters[1:5],
  number = 0:4 + 1
)
# shared data
dat_shared <- crosstalk::SharedData$new(dat)

# custom js (contains unfinised code for date filter!)
custom_js <-   shiny::tags$script('
    // this is not complete and it does not work
    function filter_date(){
      document.getElementById("date")
    }
    $(document).ready(filter_date);
    
    
    // this is an example how a default selection can be done using JS which works
    // it selects a for the filter (the default is that nothing is selected)
    // I want to do something similar, but for a date filter
    function filter_cat(){
      document.getElementById("filter_cat").getElementsByClassName("selectized")[0].selectize.setValue("a",false)
    }
    $(document).ready(filter_cat);
    '
)

# filters for the widget
filter_cat <- crosstalk::filter_select(
  "filter_cat", "Select a letter",
  dat_shared, ~letter, multiple = F
)


filter_date <-  crosstalk::filter_slider(
  "filter_date", "Date",
  dat_shared, ~date
)


# showing the widget in RStudio
htmltools::browsable(htmltools::tagList(
  custom_js, filter_date, filter_cat
))