Fluid code :)

Ottavia M. Epifania

Why did I break?

Look at the code

appExamples/brokenApp-dataUpload.R

• UI
• Server

ui = fluidPage(
  sidebarLayout(sidebarPanel(
      selectInput(inputId = "dataset",
                  label = "Choose a dataset:",
                  choices = list("rock" = 1, 
                                 "pressure" = 2,
                                 "cars" = 3,
                                 "I want to use my data!!" =4)), 
      # Let me introduce you Mr. Conditional Panel
      conditionalPanel(
        condition = "input.dataset == '4'", # What is the condition for which I should show up?
        # What should be displayed inside me once I show up?
        fileInput("example",  # label for the server
                  "", # no displayed label for users
                  accept = c("csv")) # what format do we accept?
      ),
      actionButton("load", "Upload data")
    ),
    mainPanel(
      plotOutput(
        "graph"
      ),
      verbatimTextOutput(
        "summary"
      )
    ) # display output
  )
)

server = function(input, output){
  values <- reactiveValues()
  dataInput <- reactive({
    if(input$dataset == 1){ 
      data <- rock
    } else if (input$dataset == 2 ){
      data <- pressure
    } else if (input$dataset == 3) {
      data <- cars
    } else if (input$dataset == 4) {
      data <- read.csv(input$example$datapath) 
    }
  })
observeEvent(input$load, {
    values$data <- data.frame(dataInput())
  })
output$graph <- renderPlot({
    validate(need(input$load > 0, "Waiting for data"))
if (any(colnames(values$data) == "condition") ){ 
  if (any(sapply(values$data, is.character)) == TRUE) {
  values$data[, sapply(values$data, is.character) == T] = lapply(values$data[,   sapply(values$data, is.character) == T], as.factor)
      } else {
  values$data = values$data
    }
plot(values$data$tr ~ values$data$condition, xlab = "Condition", ylab = "TR")
} else {
      plot(values$data[, c(1:2)])
    }
})
output$summary <- renderPrint({
    validate(need(input$load > 0, "Waiting for data"))
  if (any(colnames(values$data) == "condition") ){
      summary(values$data[, c(2:3)])
    } else {
      summary(values$data[, c(1:2)])
    }
  })
}

Code has to be fluid and adapt to everything

We have the code for uploading a data frame.

The code is designed to work for that specific data frame

If only we had a way to explore the data frame columns and choose the ones we would like to plot 🤔

Way better :)

Choose a dataset:

rock pressure cars I want to use my data!!

Browse...

A flow in a flow

• Step 0
• Step 1
• Step 2
• Step 3

The code

• UI
• Server
• Together

ui = fluidPage(
  sidebarLayout(
    sidebarPanel(
      selectInput(inputId = "dataset",
                  label = "Choose a dataset:",
                  choices = list("rock" = 1,
                                 "pressure" = 2,
                                 "cars" = 3,
                                 "I want to use my data!!" =4)),
      conditionalPanel(condition = "input.dataset == '4'",
        fileInput("example", "", accept = c("csv"))
      ), 
      actionButton("load", "Upload data"),                              
      conditionalPanel(condition = "input.load >= '1'",   
        uiOutput("var1"),                 
        uiOutput("var2"),                 
        actionButton("select", "Select & Display") 
      ),                              
    ),
    mainPanel(
      plotOutput(
        "graph"
      ),
    verbatimTextOutput(
        "summary"
      )
    ) 
  )
)

server = function(input, output){
  values <- reactiveValues()
  dataInput <- reactive({
    if(input$dataset == 1){
      data <- rock
    } else if (input$dataset == 2 ){
      data <- pressure
    } else if (input$dataset == 3) {
      data <- cars
    } else if (input$dataset == 4) {
      data <- read.csv(input$example$datapath)
    }
  })
observeEvent(input$load, {
    values$data <- data.frame(dataInput())
    if (any(sapply(values$data, is.character)) == TRUE) {
      values$data[, sapply(values$data, is.character) == T] = lapply(values$data[, sapply(values$data, is.character) == T], as.factor)
    } else {
      values$data = values$data
      }
  })
output$var1 <- renderUI({   
    nam <- colnames(values$data)
    selectInput("var1", label = "Select x:", 
                choices = c(nam), multiple = FALSE,
                selected = nam[1])
  })
output$var2 <- renderUI({
    nam2 <- colnames(values$data) 
    selectInput("var2", label = "Select y:",
                choices = c(nam2), multiple = FALSE,
                selected = nam2[1])
  })
newdata <- observeEvent(input$select, { 
  values$df <- values$data[c(input$var1, input$var2)]
                          })
output$graph <- renderPlot({
    validate( need(input$select > 0, "Waiting for data"))          
df <- values$df 
    plot(df[, c(1:2)]) 
  })
output$summary <- renderPrint({
    validate(need(input$select > 0, "Waiting for data")) 
    df <- values$df # same 
    summary(df[, c(1:2)])
  })
}

shinyApp(ui, server)