renderUI_help

library(shiny)
demo=data.frame(
   brand=c("a","a","a","a","a","a","b","b","b","b","b","c","c","c","c","c"),
   model=c("a11","a11","a21","a21","a31","a31","b55","b55","b56","b56","b56","c33","c34","c34","c33","c34"),
   tax=c("y","x","y","x","x","y","x","x","x","y","y","x","y","x","y","y"),
   seller=c("A","B","B","C","C","D","A","D","B","C","D","B","A","C","C","D"),
   price=c(1000,1100,1500,1400, 1200,   1300,   2000,   2200,   1900,   1800,   1700,   800,    900,    850,    950,    880),stringsAsFactors = F
)
runApp(list(

   ui = shinyUI(fluidPage(
         titlePanel("dynamic renderUI test"),
         sidebarLayout
         (
         sidebarPanel
         (width=3,
         selectInput("brand",label="my dynamic brand",choices=c("all","a","b","c"),selected="all"),
         uiOutput("ui1"),
         uiOutput("ui2"),
         uiOutput("ui3")
         ),

         mainPanel
         (
         navbarPage(
            title="",
            tabPanel("dynamic table test",dataTableOutput("table"))
         )
         )
         )))

, server = function(input, output) ({
   output$ui1=renderUI({
      selectInput("model","select the model",choices=c("all",sort(unique(demo[demo$model==input$model]$model))))
   })

   output$ui2=renderUI({
      selectInput("tax","select the tax",choices=c("all",sort(unique(demo[demo$tax==input$tax]$tax))))
   })

   output$ui3=renderUI({
      selectInput("seller","select the seller",choices=c("all",sort(unique(demo[demo$seller==input$seller]$seller))))
   })

   output$table=renderTable({
      demo
   })
      })
  )
)