Highlights from the Shiny Developer Conference

Website: http://www.rstudio.com/shinydevcon
Videos: https://www.rstudio.com/resources/webinars/shiny-developer-conference
Twitter: #shinydevcon

Reactivity tutorial | Joe Cheng

Author of the Shiny reactive programming framework explains the philosophy behind reactivity and explores patterns and techniques for using it well.

• Prefer using reactive expressions to model calculations, over using observers to set (reactive) variables.
• Use reactive expressions for calculations (no side effects). Use observers for actions (side effects).

reactive()	observe()
Callable	Not callable
Returns a value	No return value
Lazy	Eager
Cached	N/A

Slides • Tutorial (see with-solutions branch for answers) • R-Podcast

Interactive graphics | Winston Chang

• add/select single points using click, dblcick, and hover
• linked brushing

Slides

Shiny Gadgets | Hadley Wickham

Things that are hard to express with code but you want to do reproducibly -- Hadley Wickham

Build interactive graphical tools for exploratory data analysis that run locally, taking your data as input and returning a result.

Article

Modules | Garrett Grolemund

Manage complex Shiny apps by modularizing their code.

Slides • Tutorial • Article

Debugging Shiny applications | Jonathan McPherson

Debugging

• breakpoints using RStudio
• conditional breakpoints with browser()

Tracing

• showcase mode: runApp(..., display.mode = "showcase")
• reactive log: options(shiny.reactlog = TRUE), start visualization in app by hitting Ctrl+F3
• print to console: cat
• shinyapps.io: rsconnect::showLogs(streaming = TRUE)
• Shiny Server: tail -f /var/log/shiny-server/myapp-20160131-104403-8492.log
• client/server: options(shiny.trace = TRUE)

Error handling

• stack traces
• pause on errors: options(shiny.error = browser)
• JavaScript dev mode on OS X: defaults write org.rstudio.RStudio WebKitDeveloperExtras -bool true

Slides • Article

HTML templates

Author the structure and style of your app's UI in HTML, but still conveniently insert input and output widgets using R functions.

Article

Building dashboards | Nathan Stephens

An increasingly popular use of Shiny is in building dashboards, especially since the release of the shinydashboard package.

Project website

Profiling | Winston Chang

Use profvis to find and fix performance bottlenecks to make your apps as responsive as possible.

Vignette

Data Tables | Yihui Xie

The R package DT is an interface to the DataTables JavaScript library which renders HTML tables that can be paginated, filtered, and sorted.

shinyjs | Dean Attali

Perform common JavaScript operations in Shiny apps using plain R code

• hide an element
• disable an input
• reset an input back to its original value
• delay code execution by a few seconds
• run your own custom JavaScript functions from R
• color picker

CRAN • GitHub • R-Podcast • Live demo

Radiant - Business analytics using R and Shiny | Vincent Nijs

GitHub • Documentation • R-Podcast • Live demo

Grid Style Sheets 2.0 | Yihui Xie

http://gridstylesheets.org/

Bindings to popular JavaScript libraries | Herman Sontrop (Friss)

GitHub - tutorials will appear soon

Further reading

• Shiny Developer Conference 2016 Recap by VP Nagraj
• Shiny Developers Conference Review by Aimee Gott
• Shiny Developer Conference by John Mount
• DataScienceLA interviews with by Joe Cheng, Yihui Xie, Hadley Wickham and JJ Alaire