This workshop stage will get you started with the Shiny web framework, creating both a simple demo to interact with sample data, and more complex application which lets you explore current information regarding Coronavirus and COVID-19.
You'll find excellent tutorial materials for building a Shiny app from scratch at Shiny tutorial, but to get going quickly, we'll exploit the power of the RStudio IDE.
You'll find plenty of inspirational Shiny apps at the Shiny gallery and ShinyApps
First, create a new Shiny folder from your home directory in the Files view (bottom-right section)
Then, from the main Menu, select File -> New File -> Shiny Web App ...; you should be prompted to create a new app. Configure the name and location, and click Create
You should now see you have a folder at "/Home/shiny/helloworld", and two source files - ui.R and server.R - loaded into the editor view (top-right)
This demo app shows a plot of data from the Old Faithful Geyser sample dataset built into RStudio.
A data frame with 272 observations on 2 variables.
[,1] eruptions numeric Eruption time in mins
[,2] waiting numeric Waiting time to next eruption (in mins)
Waiting time between eruptions and the duration of the eruption for the Old Faithful geyser in Yellowstone National Park, Wyoming, USA.
The app can be launched immediately using the > Run App button in the editor.
Shiny apps are built from 2 components:
server.R- contains all the logic needed to provide data to, and perform any actions requested by, the front-end UIui.R- has all the user-interface logic to render data views, and capture user interactions for transmission to the server
Modern Shiny apps may have these two components incorporated in a single source file app.R, but the content is essentially the same as the separate files.
Run ?shiny-package from the RStudio console to bring up the help for the Shiny package, and all its functions.
For example, check out shiny::plotOutput - the function in the sample ui.R which renders the bar plot.
To see a more sophisticated implementation of Shiny, check out http://shinyapps.org/apps/corona/
The source for this app is available at Felix Schönbrodt's Git repo; you can download and import into RStudio. Download to your local machine in ZIP form, then use the Upload option in the Files view - RStudio will automatically unzip into a folder.
Open the server.R or ui.R in the editor, and click > Run App, and away you go!
