Flexdashboard: Make a reactive dataframe based on drop down inputs

Question

I am trying to create a data frame whose content changes based on the inputs of the user of the dashboard. I have set up the empty data frame and the input like so:

selectInput("ai_issue", 
            label = "Select Issue Area:",
            choices = c("Environment",
                        "Human rights",
                        "Refugee relief"))

beta <- as.data.frame(matrix(rep(0), nrow = 3))
beta$levels = c("Environment", "Human Rights", "Refugee Relief")

I am wanting to code the beta data frame so that if the user selects 'Environment' from the drop down of the ai_issue object the appropriate cell within the beta data frame will change to 1. Does anyone know how to do this?

Answer 1

This example uses multiple for inputSelect so you can indicate one or more choices.

A reactive function will set your data frame variable depending on the input selection.

This is something I hope can help in getting you started. If this is not what you had in mind please let me know.

library(shiny)

beta <- data.frame(
  value = c(0,0,0),
  levels = c("Environment", "Human Rights", "Refugee Relief")
)

ui <- fluidPage(
  fluidRow(
    column(6,
      selectInput("ai_issue", 
                  label = "Select Issue Area:",
                  choices = beta$levels,
                  multiple = TRUE)
    ),
    column(6,
      tableOutput("data")
    )
  )
)

server = function(input, output) {

  df <- reactive({
    beta$value[beta$levels %in% input$ai_issue] <- 1
    beta
  })

  output$data <- renderTable({
    df()
  })
}

shinyApp(ui, server)