shinyFeedback Introduction

Functionality

The shinyFeedback package creates a user friendly message that appears along side a shiny input. Here are pictures of shiny inputs with feeback messages displayed:

shinyFeedback provides a friendly way to guide your users on how to use your app.

shinyFeedback currently only works with the following shiny::*Input() functions:

• numericInput()
• textInput()
• passwordInput()
• selectInput()

More inputs and display options will be supported in future versions of shinyFeedback

Setup

In order to use shinyFeedback you need to include the following function at the top of your UI.

useShinyFeedback()

The following is a minimal example of a shiny app that uses shinyFeedback. Run the following code in your R console to run the app.

library(shiny)
library(shinyFeedback)

ui <- fluidPage(
  useShinyFeedback(), # include shinyFeedback
  
  numericInput(
    "warningInput",
    "Warn if Negative",
    value = -5
  )
)

server <- function(input, output) {
  observeEvent(input$warningInput, {
    feedbackWarning(
      inputId = "warningInput",
      condition = input$warningInput < 0
    )
  })
}

shinyApp(ui, server)

The above app uses the feedbackWarning() function to display a default warning feedback message. feebackWarning() is a wrapper around the more general feedback() function.

The feedback function

The primary function provided by shinyFeedback is feedback(). feedback() creates messages similar to those shown in the image at the top of this vignette. The color, icon, and text of the feedback message can be customized.

To use feedback(), you will want to call it from inside a shiny observer (either shiny::observe() or shiny::observeEvent()).

Handy feedback wrappers

shinyFeedback has 3 convenient wrappers functions:

• feedbackWarning()
• feedbackDanger()
• feedbackSuccess()

The above functions provide default arguments for all the formal arguments in the feedback function other than inputId and condition. A live app using these functions is available here.

Multiple feedbacks

When assigning multiple feedback()s to a single input (e.g. you want to display a certain feedback message if the input value >= 1, and a different feedback value if the input is >= 2), place the feedback()s in the same shiny observer. The feedback()s further down in the body of the observer will override the higher feedback()s if multiple feedback() function conditions evaluate to TRUE.

ui <- fluidPage(
  useShinyFeedback(), # include shinyFeedback
  
  numericInput(
    "multiFeedbacks",
    "1 is scary 2 is dangerous", 
    value = 1
  )
)

server <- function(input, output) {
  observeEvent(input$multiFeedbacks, {
    feedbackWarning(
      inputId = "multiFeedbacks",
      condition = input$multiFeedbacks >= 1,
      text = "Warning 1 is a lonely number"
    )
    feedbackDanger(
      inputId = "multiFeedbacks",
      condition = input$multiFeedbacks >= 2,
      text = "2+ is danger"
    )
  })
}

shinyApp(ui, server)

In the above example, both feedback*() function conditions are TRUE when the input is >=2. The feedbackDanger() is displayed because it is called after the feedbackWarning().