R and Shiny, linked selectInputs

sleep-visualizer.R

library(shiny)

# Just to use msleep dataset
library(ggplot2)

# Remove NAs
msleep = msleep[complete.cases(msleep), ]

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      h1("Animal's sleep"),
      h3("Choose animal type:"),
      selectizeInput(inputId = "animaltype",
                  label = "Type:",
                  c (msleep$vore),
                  options = list(onInitialize = I('function() { this.setValue("omni"); }'))),
                  
      h3("Choose your animal:"),
      # This selectInput will be updated by the server!
      selectizeInput(inputId = "animalname",
                  label = "Animal:",
                  c (msleep$name))
    ),
    mainPanel(
      plotOutput(outputId = "distPlot")
    ),
  )
)
server <- function(input,output,session){
  # Update "animalname"
  observe({
    animaltype <- input$animaltype
    updateSelectInput(session, "animalname", choices = msleep$name[msleep$vore == animaltype])
  })
  
  output$distPlot <- renderPlot({
    # He tenido que construir la tabla de esta forma!! :S
    # Mi intención era pasar al barplot algo como esto:
    #
    # Nombres = names(msleep)[6:9]
    # Valores = msleep[grep("Cow", msleep$name),6:9]
    #
    # Pero lo segundo me dice que no es un objeto de tipo vector/matrix...
    
    sleep_total = msleep$sleep_total[grep(input$animalname, msleep$name)]
    sleep_rem = msleep$sleep_rem[grep(input$animalname, msleep$name)]
    sleep_cycle = msleep$sleep_cycle[grep(input$animalname, msleep$name)]
    awake = msleep$awake[grep(input$animalname, msleep$name)]
    
    y = data.frame(Sleep=c('Sleep total','Sleep rem','Awake'),
                   Hours=c(sleep_total, sleep_rem, awake))
    
    color <-  c("#4FC3F7", "#AED581", "#FFF176")
             
    barplot(y$Hours,
            names.arg=y$Sleep,
            main = input$animalname,
            ylab = "Hours",
            xlab = "Sleep",
            ylim = range(c(0,24)),
            col = color
            )
    })
}
shinyApp(ui=ui, server=server)