R was originally developed with the name S in the 70’s as a glue language. Statisticians at Bell Labs needed an interactive environment for working with their C and Fortran scripts. Decades later, R is still a glue language, except instead of C and Fortran, it brings together C++, and JavaScript. With the advent of the Shiny package, R is now a popular platform for developing data-driven web applications. As Shiny increases in popularity so will the complexity of the Shiny apps built. In many instances, new-users will require guidance when they first use a Shiny application.
Luckily, there is already a well established JavaScript library for
this purpose. Intro.js, written by
Afshin Mehrabani, is a JavaScript library that helps integrate
step-by-step introductions, and clickable hints into websites. The
rintrojs
R package integrates Intro.js into Shiny, so that
users can easily add instructions to their application without having to
use HTML, CSS, or JavaScript.
rintrojs
is available on CRAN:
install.packages("rintrojs")
To access the bleeding-edge version, use devtools
to
install rintrojs
from github:
::install_github("carlganz/rintrojs") devtools
To use rintrojs
, you need to call
introjsUI()
once in the UI. rintrojs
supports
both static and programmatic introductions meaning you can either wrap
the elements you want to introduce with introBox
, or
dynamically generate your introduction using the steps
option (see the
Intro.js documentaion). You specify the order of the introduction
with the data.step parameter, and you specify the content of the
introduction with the data.intro parameter. You can initiate the
introduction from the server by calling introjs(session)
.
You can also specify options, and pass text as the body of javascript
events associated with Intro.js
.
Here is an example with a static introduction, but with options, and events used.
library(rintrojs)
library(shiny)
# Define UI for application that draws a histogram
<- shinyUI(fluidPage(
ui introjsUI(),
# Application title
introBox(
titlePanel("Old Faithful Geyser Data"),
data.step = 1,
data.intro = "This is the title panel"
),
# Sidebar with a slider input for number of bins
sidebarLayout(sidebarPanel(
introBox(
introBox(
sliderInput(
"bins",
"Number of bins:",
min = 1,
max = 50,
value = 30
),data.step = 3,
data.intro = "This is a slider",
data.hint = "You can slide me"
),introBox(
actionButton("help", "Press for instructions"),
data.step = 4,
data.intro = "This is a button",
data.hint = "You can press me"
),data.step = 2,
data.intro = "This is the sidebar. Look how intro elements can nest"
)
),
# Show a plot of the generated distribution
mainPanel(
introBox(
plotOutput("distPlot"),
data.step = 5,
data.intro = "This is the main plot"
)
))
))
# Define server logic required to draw a histogram
<- shinyServer(function(input, output, session) {
server # initiate hints on startup with custom button and event
hintjs(session, options = list("hintButtonLabel"="Hope this hint was helpful"),
events = list("onhintclose"=I('alert("Wasn\'t that hint helpful")')))
$distPlot <- renderPlot({
output# generate bins based on input$bins from ui.R
<- faithful[, 2]
x <- seq(min(x), max(x), length.out = input$bins + 1)
bins
# draw the histogram with the specified number of bins
hist(x,
breaks = bins,
col = 'darkgray',
border = 'white')
})
# start introjs when button is pressed with custom options and events
observeEvent(input$help,
introjs(session, options = list("nextLabel"="Onwards and Upwards",
"prevLabel"="Did you forget something?",
"skipLabel"="Don't be a quitter"),
events = list("oncomplete"=I('alert("Glad that is over")')))
)
})
# Run the application
shinyApp(ui = ui, server = server)
You can also generate introductions dynamically.
library(shiny)
library(rintrojs)
<- shinyUI(fluidPage(
ui introjsUI(),
mainPanel(
textInput("intro","Enter an introduction"),
actionButton("btn","Press me")
)
)
)
<- shinyServer(function(input, output, session) {
server
<- reactive(data.frame(element = c(NA,"#btn"),
steps intro = c(input$intro,"This is a button")))
observeEvent(input$btn,{
introjs(session,options = list(steps=steps()))
})
})
# Run the application
shinyApp(ui = ui, server = server)
Click here to view example.
Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.
If you find any problems or have any questions, please feel free to file an issue.
Thanks goes to these wonderful people (emoji key):
Carl Ganz |
Afshin Mehrabani |
Etienne
Bacher |
Matthew van
Bommel |
Chris Baker |
This project follows the all-contributors specification. Contributions of any kind welcome!