What's Shiny?

An interactive report framework
An R package that is available free (as is the server edition)
Uses “modern web standards” like bootstrap under the hood
Cross-browser/Cross-device compatibility, out of box!

Quick example

library(data.table)
library(shiny)
defaultdisplay<-list(
    width="100%", height="75%"
  )
shinyAppDir(
  system.file("examples/06_tabsets", package="shiny"),
  options = defaultdisplay
)

Shiny structure

Typical Contents

A shiny application report consists of two functions:

shinyServer()
shinyUI()

One says what to execute and the other states how to present it. Do all data manipulation, chart production in shinyServer()

“Lite” Contents

defaultdisplay<-list(width="100%", height="75%")

shinyApp(
    ui      = fluidPage(),
  , server  = function(input, output) {}
  , options = defaultdisplay
)

Files

You typically split into two files:

server.R containing shinyServer()
ui.R containing shinyUI()

This can then be run with runApp()

You can do a single file example app.R which contains both functions but this is typically better for very short apps.

Front-end layout

Use these just inside shinyUI() to produce a layout

##          Page Types
## 1:        basicPage
## 2:    bootstrapPage
## 3:         fillPage
## 4:        fixedPage
## 5:        fluidPage
## 6:       navbarPage
## 7: updateNavbarPage

Typical Inputs

Dates

shinyApp(
  ui = fluidPage(dateInput("datePicker", "Pick a date:", 
                           format="dd/mm/yy"),
                 dateRangeInput("dateRange", "Pick dates:", 
                                start=Sys.Date(), 
                                end=Sys.Date() ) ),
  server = function(input, output) {}
  ,options = defaultdisplay
)

Values

Basic

shinyApp(
  ui = fluidPage(numericInput("vals", "Insert a number:", 
                              value=15, min=10)  ),
  server = function(input, output) {}
  ,options = defaultdisplay
)

Sliders

shinyApp(
  ui = fluidPage(sliderInput("vals", "Insert a number:", 
                             min=0, max=50, value=15)  ),
  server = function(input, output) {}
  ,options = defaultdisplay
)

Text

A single line

shinyApp(
  ui = fluidPage(textInput("char", "Insert text:")  ),
  server = function(input, output) {}
  ,options = defaultdisplay
)

A paragraph

shinyApp(
  ui = fluidPage(tags$textarea(id="charbox", rows=3, 
                               cols=40, "Default value")  ),
  server = function(input, output) {}
  ,options = defaultdisplay
)

Selectors

shinyApp(
  ui = fluidPage(selectInput("multiselect", "Pick favourites:",
                             c("Green","Red","Blue"),
                             multiple=TRUE)  ),
  server = function(input, output) {}
  ,options = defaultdisplay
)

List of input types

##               Input controls
##  1:       checkboxGroupInput
##  2:            checkboxInput
##  3:                dateInput
##  4:           dateRangeInput
##  5:                fileInput
##  6:             numericInput
##  7:            passwordInput
##  8:     registerInputHandler
##  9:       removeInputHandler
## 10:             restoreInput
## 11:              selectInput
## 12:           selectizeInput
## 13:              sliderInput
## 14:            textAreaInput
## 15:                textInput
## 16: updateCheckboxGroupInput
## 17:      updateCheckboxInput
## 18:          updateDateInput
## 19:     updateDateRangeInput
## 20:       updateNumericInput
## 21:        updateSelectInput
## 22:     updateSelectizeInput
## 23:        updateSliderInput
## 24:      updateTextAreaInput
## 25:          updateTextInput
##               Input controls

Typical Outputs

Input values

shinyApp(
  ui = fluidPage(textInput("char", "Insert text:") ,
                 textOutput("text")  ),
  server = function(input, output) {
    output$text <- renderText(input$char)
  }  ,options = defaultdisplay
)

Basic tables

shinyApp(
  ui = fluidPage(tableOutput("basictable")  ),
  server = function(input, output) {
    output$basictable <- renderTable(head(iris,5))
  }  ,options = defaultdisplay
)

Interactive tables

shinyApp(
  ui = fluidPage(dataTableOutput("datatable")  ),
  server = function(input, output) {
    output$datatable <- renderDataTable(head(iris,5))
  }  ,options = defaultdisplay
)

Charts

shinyApp(
  ui = fluidPage(plotOutput("chart")  ),
  server = function(input, output) {
    output$chart <- renderPlot(pairs(iris))
  }  ,options = defaultdisplay
)

Reactivity

Simple reactivity

Make functions that process inputs only when they change

a <- reactive({input$a})
a

Use these reactive functions in downstream server items for DRY & to reduce processing effort

An Example

shinyApp(
  ui = fluidPage(textInput("char", "Insert text:") ,
                 textOutput("textA"),textOutput("textB") ),
  server = function(input, output) {
    char<-reactive({rep(input$char,5)})
    output$textA <- renderText(paste(char(),collapse="+"))
    output$textB <- renderText(paste(char(),collapse="-"))
  }
  ,options = defaultdisplay
)

Styling

shinythemes

Get a different look and feel with the package shinythemes
Uses a number of bootstrap based themes
Good-looking quickly, but of course not company branded
View themes at bootswatch.com

CSS

Shiny outputs html so you can write CSS that works with it
Full list of CSS items doesn't exist, use F12 on chrome or check out selectorgadget via rvest
Simple stuff like body, h1 will all work

shinydashboards

Makers of shiny working on a framework: Shiny Dashboard
A new dashboarding framework - still immature but useful
Excellent walkthrough on Data Driven Security

Infrastructure

Ad-hoc shiny

Rstudio (easiest) or just run directly
Use shiny::runApp()
Great for “expert” use

Cloud

shinyApps.io
Deploy with shinyApps package
Free for light use
Extra management features at increased costs
Great for hands-off management

Central server

shiny-server
Runs on linux
Free community edition
Extra management features & LDAP auth in Pro Edition (but can roll your own)
Great for sensitive and/or db-driven appplications