Hey y'all. Solved it. Needed to use updateSelectInput on the server side with a plain ol' sideBarMenu on the user side. Here's the code with the desired functionality:
ui <- dashboardPage(
dashboardHeader(title="Some Header"),
dashboardSidebar(
sidebarMenu(id="sbm"
,menuItem("Menu",tabName="m_1",icon = icon("th")
,menuSubItem("Menu Item 1", tabName="mi_1")
,menuSubItem("Menu Item 2", tabName="mi_2")
,menuSubItem("Menu Item 3", tabName="mi_3")
)
)
,sidebarMenu(id="dependent_dropdown",
menuItem("Dependent Dropdown",icon=icon("database")
,selectInput("dropdown_selection"
,"Menu Item List:"
,choices=c()
,selected=NULL)
)
)
),
dashboardBody(
uiOutput("checkItemValue")
,uiOutput("checkListValue")
)
)## end user function
server <- function(input, output, session){
react_val <- reactiveValues()
observeEvent(input$sbm,{
react_val$selected_list <- paste0(input$sbm,"_Li_",1:6)
react_val$initial_selection <- paste0(input$sbm,"_Li_",1:6)[1]
updateSelectInput(session,"dropdown_selection",
label = paste0("Menu Item ",gsub("mi_","",input$sbm)," List:"),
choices = react_val$selected_list,
selected = react_val$initial_selection)
})
output$checkItemValue <- renderText({
paste0("Menu Item ",gsub("mi_","",input$sbm)," selected")
})
output$checkListValue <- renderText({
paste0("List Item ",gsub(paste0(input$sbm,"_Li_"),"",input$dropdown_selection)," selected")
})
}## end server function