Reactive selectizeInput box fail to update correctly in Shiny 1.8.0, first value of previous allowed choices are kept about shiny HOT 2 OPEN

Hi @Roleren, thanks for the bug report!

One important detail: this only happens when server = TRUE. In this case, the full set of choices are kept back on the server because they could be potentially large and are only sent to the client app when requested. If you completely change the available choices, the client won't know that the current (about to be old) values are no longer valid, so it keeps those values as options.

We can do slightly better than the current situation when selected is provided. I've just added a bit of code in #3967 that will clear the current value of the select input before performing the choices update when selected is provided.

Here are two other options to get around this issue with released shiny:

1. Use fully client-side selectize inputs, i.e. server = FALSE.

2. Manually clear the selection before updating the choices and current value, but having an observeEvent() that first clears the selection:

   choices <- reactive({
     if (input$selectID == "Numeric") {
       as.character(seq(5))
     } else {
       LETTERS[1:5]
     }
   })
   
   observeEvent(choices(), {
     # Clear the selection before updating choices
     updateSelectizeInput(
       inputId = "library",
       selected = NULL,
       server = TRUE
     )
   })
   
   observeEvent(choices(), {
     updateSelectizeInput(
       inputId = "library",
       choices = choices(),
       selected = choices()[1],
       server = TRUE
     )
   })

from shiny.

Thanks, this should solve the issue for now. As far as I understand, the old value is still kept if selected is not specified ?

from shiny.