Problem with server.R : not able to use observeEvent in actionButton properly

Question

I am relatively new to shiny app and is trying to make a simple app : while i am able to run ui.R correctly, i am having problem with server.R......what i want is to take a value of slider bar "post" (this number will be used as arg. of function "wbpg"),select the type of plot from dropdown menu and plot the corresponding variable when action button "RUN" is pushed.....all the results and plots are saved when a function named "wbpg(x)" (where "x" is the value of slider bar)...when wbpg(x) is run it returns plots(this contains list of all the plots in drop down menu)

#UI.R
shinyUI( fluidPage(
  titlePanel(title=h4("Text Mining on  thread",align="centre")),

sidebarLayout(
    sidebarPanel(
  sliderInput("post","1. Choose no. of posts you want to run the model",value = 1, min = 1, max = 30000),
  br(),
  selectInput("plotvar","2. Select the variable you want to plot",choices=c("raw_dat"=1,"content"=2,"barplot"=3,"genderplot"=4,"girlplot"=5,"rawplot"=6,"adjplot"=7,
           "drinkplot"=8,"damageplot"=9,"songplot"=10,"sentimentplot"=11)),
  br(),
  actionButton(inputId="act",label = "RUN!")

  ),

  mainPanel(
    textOutput("out"),
    #tableOutput("tab"),
    plotOutput("hist1")
  )
)
))

this is server file, where the problem exists:

#server.R
shinyServer(function(input, output) {
    #observeEvent(input$action,wbpage(as.numeric(input$post)))
    #output$data<-renderPrint({str(get(content))})
  observeEvent(input$act,{wbpg(np)})  

  output$out<-renderText(paste("No. of posts mined: ",input$post))

#defaul<-reactiveValues(data=wbpage(3000))
np<-wbpage(as.numeric(input$post))



output$hist1 <- renderPlot({barplot})

}) 
#output$hist1 <- 
    #renderPlot({
      #plots$barplot
    #output$tab<-
  #   renderTable({ 
  #  head(data())
    #})
  #output$hist2 <- renderPlot({
  #hist(rnorm(input$num))
  #raunchyplot
  #})
#}) 

Answer 1

Without having access to your function (wbpg), let me try to help you with the values returned from the 'observeEvent' call. I think your problem is the placement of the '})' on the line with 'observeEvent'. Everything you want to happen upon clicking the 'Run' button needs to be within the '})'. If this isn't what you need, please restate the question.

In place of your 'observeEvent' command, use the following code to see the data returned every time you click on the 'Run' button. It shows the value of the slider bar and the number from the drop down menu.

  observeEvent(input$act,{
    print (paste(input$post,input$plotvar,sep=' '))
  })