Shiny中SelectizeGroup如何设置输入默认值？

Absolutely! You can set default selected values for your selectizeGroup inputs using the selected parameter in the selectizeGroupServer module. This works similarly to the selected argument in selectizeInput, but you pass a named list where each name corresponds to one of your variables, and the value is the default selection(s).

Modified Code with Default Selection #

Here's how to adjust your server code to pre-select the first value of var_one when the app starts:

a_df <- tibble(
  var_one = c("hadley", "charlotte", "rené", "raymond"),
  var_two = c("mutate", "filter", "slice", "spread"),
  var_three = c("an apple", "a pipe", "a cocktail", "a dog"),
  var_four = c("with", "without", "thanks", "out of"),
  var_five = c("tidyr", "magrittr", "purrr", "dplyr")
)
ex_df <- expand.grid(a_df)
tib <- as_tibble(sample_n(ex_df, 40))
library(shinyWidgets)
shinyApp(
  ui = pageWithSidebar(
    headerPanel("Painting 8"),
    sidebarPanel(
      selectizeGroupUI(
        id = "my-filters",
        inline = FALSE,
        params = list(
          var_one = list(inputId = "var_one", title = "Select variable 1", placeholder = 'select'),
          var_two = list(inputId = "var_two", title = "Select variable 2", placeholder = 'select'),
          var_three = list(inputId = "var_three", title = "Select variable 3", placeholder = 'select'),
          var_four = list(inputId = "var_four", title = "Select variable 4", placeholder = 'select'),
          var_five = list(inputId = "var_five", title = "Select variable 5", placeholder = 'select')
        )
      )
    ),
    mainPanel(
      tableOutput("table")
    )
  ),
  server = function(input, output, session) {
    res_mod <- callModule(
      module = selectizeGroupServer,
      id = "my-filters",
      data = tib,
      vars = c("var_one", "var_two", "var_three", "var_four", "var_five"),
      # Add the selected parameter to set defaults
      selected = list(var_one = unique(tib$var_one)[1])  # Pre-select first unique value of var_one
    )
    output$table <- renderTable({
      res_mod()
    })
  },
  options = list(height = 500)
)

Key Details: #

• Single-select defaults: For single-select inputs (your case), pass a single value—either dynamically pull the first unique value from your data like unique(tib$var_one)[1], or hardcode a specific value such as "hadley".
• Multi-select defaults: If you enable multi-select for an input by adding multiple = TRUE to its params entry, you can pass a vector of values (e.g., var_two = c("mutate", "filter")) to pre-select multiple options.
• No default for inputs: Simply omit variables from the selected list if you want them to start with no selection (like your var_two to var_five in this example).

This approach ensures your app starts with the desired pre-selected value for var_one, while leaving other inputs empty as requested.

内容的提问来源于stack exchange，提问作者Marco Fumagalli