My First (R) Shiny App: An Annotated Tutorial

Image Credit: Doug Buckley of http://hyperactive.to

I’ve been meaning to learn Shiny for 2 years now… and thanks to a fortuitous email from @ImADataGuy this morning and a burst of wild coding energy about 5 hours ago, I am happy to report that I have completely fallen in love again. The purpose of this post is to share how I got my first Shiny app up and running tonight on localhost, how I deployed it to the http://shinyapps.io service, and how you can create a “Hello World” style program of your own that actually works on data that’s meaningful to you.

If you want to create a “Hello World!” app with Shiny (and your own data!) just follow these steps:

0. Install R 3.2.0+ first! This will save you time.
1. I signed up for an account at http://shinyapps.io.
2. Then I clicked the link in the email they sent me.
3. That allowed me to set up my https://radziwill.shinyapps.io location.
4. Then I followed the instructions at https://www.shinyapps.io/admin/#/dashboard
(This page has SPECIAL SECRET INFO CUSTOMIZED JUST FOR YOU ON IT!!) I had lots 
of problems with devtools::install_github('rstudio/shinyapps') - Had to go 
into my R directory, manually delete RCurl and digest, then 
reinstall both RCurl and digest... then installing shinyapps worked.
Note: this last command they tell you to do WILL NOT WORK because you do not have an app yet! 
If you try it, this is what you'll see:
> shinyapps::deployApp('path/to/your/app')
Error in shinyapps::deployApp("path/to/your/app") : 
C:UsersNicoleDocumentspathtoyourapp does not exist
5. Then I went to http://shiny.rstudio.com/articles/shinyapps.html and installed rsconnect.
6. I clicked on my name and gravatar in the upper right hand corner of the 
https://www.shinyapps.io/admin/#/dashboard window I had opened, and then clicked 
"tokens". I realized I'd already done this part, so I skipped down to read 
"A Demo App" on http://shiny.rstudio.com/articles/shinyapps.html
7. Then, I re-installed ggplot2 and shiny using this command:
install.packages(c('ggplot2', 'shiny'))
8. I created a new directory (C:/Users/Nicole/Documents/shinyapps) and used
setwd to get to it.
9. I pasted the code at http://shiny.rstudio.com/articles/shinyapps.html to create two files, 
server.R and ui.R, which I put into my new shinyapps directory 
under a subdirectory called demo. The subdirectory name IS your app name.
10. I typed runApp("demo") into my R console, and voila! The GUI appeared in 
my browser window on my localhost.
-- Don't just try to close the browser window to get the Shiny app 
to stop. R will hang. To get out of this, I had to use Task Manager and kill R.
--- Use the main menu, and do Misc -> Stop Current Computation
11. I did the same with the "Hello Shiny" code at http://shiny.rstudio.com/articles/shinyapps.html. 
But what I REALLY want is to deploy a hello world app with MY OWN data. You know, something that's 
meaningful to me. You probably want to do a test app with data that is meaningful to you... here's 
how you can do that.
12. A quick search shows that I need jennybc's (Github) googlesheets package to get 
data from Google Drive viewable in my new Shiny app.
13. So I tried to get the googlesheets package with this command:
devtools::install_github('jennybc/googlesheets')
but then found out it requires R version 3.2.0. I you already have 3.2.0 you can skip 
to step 16 now.
14. So I reinstalled R using the installr package (highly advised if you want to 
overcome the agony of upgrading on windows). 
See http://www.r-statistics.com/2013/03/updating-r-from-r-on-windows-using-the-installr-package/
for info -- all it requires is that you type installR() -- really!
15. After installing R I restarted my machine. This is probably the first time in a month that 
I've shut all my browser windows, documents, spreadsheets, PDFs, and R sessions. I got the feeling 
that this made my computer happy.
16. Then, I created a Google Sheet with my data. While viewing that document, I went to 
File -> "Publish to the Web". I also discovered that my DOCUMENT KEY is that 
looooong string in the middle of the address, so I copied it for later:
1Bs0OH6F-Pdw5BG8yVo2t_VS9Wq1F7vb_VovOmnDSNf4
17. Then I created a new directory in C:/Users/Nicole/Documents/shinyapps to test out 
jennybc's googlesheets package, and called it jennybc
18. I copied and pasted the code in her server.R file and ui.R file
from https://github.com/jennybc/googlesheets/tree/master/inst/shiny-examples/01_read-public-sheet 
into files with the same names in my jennybc directory
19. I went into my R console, used getwd() to make sure I was in the
C:/Users/Nicole/Documents/shinyapps directory, and then typed
 runApp("jennybc")
20. A browser window popped up on localhost with her test Shiny app! I played with it, and then 
closed that browser tab.
21. When I went back into the R console, it was still hanging, so I went to the menu bar 
to Misc -> Stop Current Computation. This brought my R prompt back.
22. Now it was time to write my own app. I went to http://shiny.rstudio.com/gallery/ and
found a layout I liked (http://shiny.rstudio.com/gallery/tabsets.html), then copied the 
server.R and ui.R code into C:/Users/Nicole/Documents/shinyapps/my-hello -- 
and finally, tweaked the code and engaged in about 100 iterations of: 1) edit the two files, 
2) type runApp("my-hello") in the R console, 3) test my Shiny app in the 
browser window, 4) kill browser window, 5) do Misc -> Stop Current Computation 
in R. ALL of the computation happens in server.R, and all the display happens in ui.R:

server.R:

library(shiny)
library(googlesheets)
library(DT)

my_key <- "1Bs0OH6F-Pdw5BG8yVo2t_VS9Wq1F7vb_VovOmnDSNf4"
my_ss <- gs_key(my_key)
my_data <- gs_read(my_ss)

shinyServer(function(input, output, session) {
 output$plot <- renderPlot({
 my_data$type <- ordered(my_data$type,levels=c("PRE","POST"))
 boxplot(my_data$score~my_data$type,ylim=c(0,100),boxwex=0.6)
 })
 output$summary <- renderPrint({
 aggregate(score~type,data=my_data, summary)
 })
 output$the_data <- renderDataTable({
 datatable(my_data)
 })

})

ui.R:

library(shiny)
library(shinythemes)
library(googlesheets)

shinyUI(fluidPage(
 
 # Application title
 titlePanel("Nicole's First Shiny App"),
 
 # Sidebar with controls to select the random distribution type
 # and number of observations to generate. Note the use of the
 # br() element to introduce extra vertical spacing
 sidebarLayout(
 sidebarPanel(
     helpText("This is my first Shiny app!! It grabs some of my data 
from a Google Spreadsheet, and displays it here. I      
also used lots of examples from"),
     h6(a("http://shiny.rstudio.com/gallery/", 
href="http://shiny.rstudio.com/gallery/", target="_blank")),
     br(),
     h6(a("Click Here for a Tutorial on How It Was Made", 
href="http://qualityandinnovation.com/2015/12/08/my-first-shin     
y-app-an-annotated-tutorial/",
      target="_blank")),
      br()
 ),
 
 # Show a tabset that includes a plot, summary, and table view
 # of the generated distribution
 mainPanel(
    tabsetPanel(type = "tabs", 
    tabPanel("Plot", plotOutput("plot")), 
    tabPanel("Summary", verbatimTextOutput("summary")), 
    tabPanel("Table", DT::dataTableOutput("the_data"))
 )
 )
 )
))



23. Once I decided my app was good enough for my practice round, it was time to 
deploy it to the cloud.
24. This part of the process requires the shinyapps and dplyr 
packages, so be sure to install them:

devtools::install_github('hadley/dplyr')
library(dplyr)
devtools::install_github('rstudio/shinyapps')
library(shinyapps)
25. To deploy, all I did was this: setwd("C:/Users/Nicole/Documents/shinyapps/my-hello/")
deployApp()

CHECK OUT MY SHINY APP!!