title: R Shiny server dateRangeInput error
body: <p>I keep finding this error</p>
  
  <h2>Error: could not find function "dateRangeInput" whenever i try to run the following application.</h2>
  
  <p>server.R </p>
  
  <hr>
  
  <pre><code>library(shiny)
  library(ggplot2)
  library(shinyExt)
  
  shinyServer(function(input, output, session) { 
  
  output$date  &lt;- renderText({ as.character(input$date)  })
  output$daterange  &lt;- renderText({ as.character(input$daterange) })
  
  observe({
  updateDateInput(session, 'date_controlled',
                  value = as.character(input$date),
                  min = as.character(input$daterange[1]),
                  max = as.character(input$daterange[2])
  )
  
  updateDateRangeInput(session, 'daterange_controlled',
                       min = as.character(input$daterange[1]),
                       max = as.character(input$daterange[2]),
                       start = as.character(input$daterange2[1]),
                       end = as.character(input$daterange2[2])
  )
  
  })  
  })
  </code></pre>
  
  <hr>
  
  <p>my ui.R</p>
  
  <hr>
  
  <pre><code>library(shiny)
  library(ggplot2)
  library(shinyExt)
  
  # Define UI for application that plots random distributions 
  shinyUI(pageWithSidebar(
  
  # Application title
  headerPanel("KEMRI Wellcome Trust Programme"),
  
  # Sidebar with a slider input for number of observations
  sidebarPanel(
  imageOutput("logo", height = "153px", width="272px"),
  helpText("Note: while the data view will show only the specified",
           "number of observations, the summary will still be based",
           "on the full dataset."),
  
  selectInput("graph", "Choose a graph:", 
              list("Histogram" = "hist", 
                   "Pie Chart" = "pie", 
                   "Time Series" = "time",
                   "Box Plot"="box",
                   "Violin Plot"="violin")),
  dateRangeInput('daterange',
                 label = 'Date range: dd/mm/yy, en, range limit, weekstart=1. Controls start and end of date range input in main panel.',
                 start = Sys.Date()-1, end = Sys.Date()+1,
                 min = Sys.Date()-10, max = Sys.Date()+10,
                 separator = " - ",
                 format = "dd/mm/yy", startview = 'year', language = 'en', weekstart = 1),
  
   submitButton("Update View")
   #sliderInput("obs","Number of observations:", min = 0, max = 1000, value = 500)
   ),
  
   # Show a plot of the generated distribution
   mainPanel(
      dateInput("date_controlled",
            "Date input controlled from sidebar"),
     dateRangeInput("daterange_controlled",
                 "Date range input controlled from sidebar")   
    )
   ))
  </code></pre>
  
  <p>What could be the problem?? I am using the latest stable shiny-server and R  3.0.x. All the examples that i've seen work, so why doesn't this one work?</p>