rhandsontable using a dropdown to "hide" columns

Question

I have a data frame that I am passing to a rhandsontable. Let's say it has 10 columns. I have a drop-down that has 3 choices:

1. Show columns 1 through 5
2. Show columns 1, 5 and 10
3. Show columns 6 through 10

Be default, when the rhandsontable loads, it will show all 10 columns. When the use selects one of the three options in the drop-down, I want to hide certain columns using the hot_col(col = col_name, width = 0.5)

For example, if the user selects option 1 - Show columns 1 through 5, hiding columns 6 through 10 would look something like:

rhandsontable(df) %>%
hot_col(col = column_6, width = 0.5) %>%
hot_col(col = column_7, width = 0.5) %>%
hot_col(col = column_8, width = 0.5) %>%
hot_col(col = column_9, width = 0.5) %>%
hot_col(col = column_10, width = 0.5)

I attempted filtering the data set with something like:

df <- if (input$dropdown == "Show columns 1 through 5") {df %>% select(1:5)}
else if (input$dropdown == "Show columns 1, 5 and 10") {df %>% select(1, 5, 10)}
else if (input$dropdown == "Show columns 6 through 10") {df %>% select(6:10)}
else {df %>% select(1:10)}

which works for only showing specific columns, but I have hot_col rules specific to different columns which bombs because if I have a rule saying that column_6 is of date type, it won't find column_6 if "Show columns 1 through 5" is chosen.

Sorry I don't have a working example, but hope this makes sense. Thanks!

Answer 1

You can determine from the selectInput which columns should be hidden and then use this information in the renderRHandsontable call to dynamically hide columns:

library(shiny)
library(rhandsontable)
ui <- fluidPage(
  fluidRow(
    column(width = 6,
           selectInput( inputId = "columns", 
                        label = "select columns",
                        choices = c("all", "first half", "second half")
           )
           
           
    ),
    rHandsontableOutput("table")
  )
)

server <- function(input, output, session) {
  
  output$table <- renderRHandsontable({
    output <- rhandsontable(mtcars[, 1:4])
    
    # determine the columns to show
    if (input$columns == "all") columns_to_hide <- NULL
    if (input$columns == "first half") columns_to_hide <- 3:4
    if (input$columns == "second half") columns_to_hide <- 1:2
    
    used_colnames <- colnames(mtcars[, 1:4])
    
    if (!is.null(columns_to_hide)) {
      for (col_name in used_colnames[columns_to_hide]) {
        output <- output %>% hot_col(col = col_name, width = 0.5)
      }
    }
    
    output
  })
}
shinyApp(ui, server)