R Shiny：将表显示为输出

Question

I am creating an R Shiny app. Everything is OK and the code runs (I have put cat() functions all other the code and I see everything works well in R Studio's console), but I don't really know how to display a table in my specific case.

My Shiny app takes user input and generate 2 datasets. It starts when the user push the button I have putted in interface (eventReactive).

The first one (dataset_1) is generated from API calls and several cleaning steps.

The second dataset (dataset_2) is generated from treatments in dataset_1.

How to structure the ui.R and server.R code to display the dataset_1 and dataset_2 (both are tables) as outputs in the user interface ?

Here are my current ui and server files:

ui.R

shinyUI(fluidPage(
   sidebarLayout(

     sidebarPanel(
        textInput("myfirstinput"),
        textInput("mysecondinput"),
        actionButton("button")
     ),
     mainPanel(
        ???????????
     )
   )
))

server.R

shinyServer(function(input, output) {
   ???????? <- eventReactive(input$button, {
       input1 <- input$myfirstinput
       input2 <- input$mysecondinput
       #function Make dataset_1 from api call (based on input1 & input2)
       dataset_1
       #function clean dataset_1
       #function Make dataset_2 from treatments in dataset_1
       dataset_2
       })
 })

In server.R file, I don't really know how to manage the eventReactive (see "????????") because I am generating 2 datasets...

Thanks!

Answer 1

If I'm understanding your question correctly, the problem is that you have one function that generates two datasets. While an eventReactive call can only return a single reactive function, that function can return a list containing any number of different objects that can be used independently. In your case, join your two datasets into a list and then return that list from your eventReactive . Then, when you call that reactive function (for example in a renderPlot or renderTable ), you can choose which list item you want to work with:

shinyUI(fluidPage(
    sidebarLayout(

        sidebarPanel(
            textInput("myfirstinput"),
            textInput("mysecondinput"),
            actionButton("button")
        ),
        mainPanel(
            tableOutput("table1"),
            tableOutput("table2")
        )
    )
)

shinyServer(function(input, output) {
    plots.dfs <- eventReactive(input$button, {
        # Make dataset_1
        # Make dataset_2
        return(list(dataset_1, dataset_2)
    })

    output$table1 <- renderTable({ plots.dfs()[[1]] })
    output$table2 <- renderTable({ plots.dfs()[[2]] })
})