Maintain names of factors when updating radio buttons' choices

[bborgesr]

Fixes #1396

[bborgesr]

After talking to Winston, I went back and fixed the original problem (#1093) better. This had been solved in #1291, but introduced the bug (#1396) that I was fixing now.

The better way does the casting to character directly in the choicesWithNames and validateSelected functions.

I had to chance tests, but everything is working as expected.

Here's an example app to make sure this works:

library(shiny)
ui <- fluidPage(
  radioButtons("rd", "radio buttons",
               c("Item A"=1, "Item B"=2, "Item C"=3)),
  selectInput("slct", "Select input", 
              c("Item A"=1, "Item B"=2, "Item C"=3)),
  checkboxGroupInput("chk", "Select input", 
                     c("Item A"=1, "Item B"=2, "Item C"=3)),
  actionButton("update","update"),
  textOutput("selected")
)

server <- function(input, output, session) {
  observeEvent(input$update, {
    updateRadioButtons(session, "rd",
                       choices = c("Item X"=1, "Item Y"=2, "Item Z"=3))
    updateSelectInput(session, "slct",
                      choices = c("Item X"=1, "Item Y"=2, "Item Z"=3))
    updateCheckboxGroupInput(session, "chk",
                      choices = c("Item X"=1, "Item Y"=2, "Item Z"=3))
  })

  output$selected <- renderText(paste("Selected:", input$RadioButtons))
}

shinyApp(ui, server)

[wch]

Could you add a test with nested lists and numbers, like:

choicesWithNames(list(A="a", B="b", C=c(D=1)))

Also, please add a NEWS entry.

[wch]

Can you add a comment to the top of this function saying it always coerces to character. And same for choicesWithNames (but for leaf nodes there).

[wch]

unname() isn't actually needed here. Maybe just use as.character() and update the comment to mention that as.character() does two things for us here: coerces type, and drops name.

[wch]

Similar test app, but setting selected instead of choices:

library(shiny)
ui <- fluidPage(
  radioButtons("rd", "radio buttons",
               c("Item A"=1, "Item B"=2, "Item C"=3)),
  selectInput("slct", "Select input", 
              c("Item A"=1, "Item B"=2, "Item C"=3)),
  checkboxGroupInput("chk", "Checkbox group", 
                     c("Item A"=1, "Item B"=2, "Item C"=3)),
  actionButton("update","update"),
  textOutput("selected")
)

server <- function(input, output, session) {
  observeEvent(input$update, {
    updateRadioButtons(session, "rd",
                       selected = 3)
    updateSelectInput(session, "slct",
                      selected = 3)
    updateCheckboxGroupInput(session, "chk",
                      selected = 3)
  })

  output$selected <- renderText(paste("Selected:", input$rd))
}

shinyApp(ui, server)

[wch]

This should also have a reference to this PR at the end (1397).

[bborgesr]

No problem, I just thought we weren't doing that, since only a handful of NEWS entries actually do that. I'll take it this is our new protocol then. I guess it makes sense to do that form now on.

[wch]

Oh yeah, I started doing that and just assumed it should be the standard for all news items. Sorry for not consulting about that. It really is a good idea though. :)

[bborgesr]

@wch I think this is finally done! I tested a few apps from the Gallery like you suggested and they're working fine. Thanks for the help!