I am trying to capture the url that has been selected when a person presses the "GET URLS" button on the app. 

What should happen is that the `event reactive()` should look at the `input$go_button` and see that it has been pressed - it should then perform the expression to take the chosen url from the select input- unfortunately it does nothing. 

I have tried debugging with browser() but still had no affect. 

All i am trying to do is capture the url that has been selected when a person "presses" the "GET URLS" button. 

my sample code is below: 

```
library(shiny)

# Use a fluid Bootstrap layout
ui <- fluidPage(    

  # Give the page a title
  titlePanel("testing select"),

  # Generate a row with a sidebar
  sidebarLayout(      

    # Define the sidebar with one input
    sidebarPanel(
      selectInput("url_selection", "select url:", 
                  choices = c(
                    '/multi-task/',
                    "/personal-account",
                    "/paperless"
                  )

                    ), 
      actionButton(inputId = "go_button", label = "Get URLS")
    ),

    # Create a spot for the barplot
    mainPanel(
      textOutput(outputId = "urls_selected_print")
    )

  )
)

server <- function(input, output) {

  url_capture <- reactive({eventReactive(eventExpr = input$go_button,
                               valueExpr = {
                                 message("capturing url chosen in selectize input")

                                 chosen_url <- input$url_selection
                                 browser()
                                 return(chosen_url)

                               })
  })

}

shinyApp(ui, server)

```