Required packages

We have already worked with the first two packages, namely ggplot2 and lubridate. The shiny package is used to build web applications directly from R, while the shinythemes and ggthemr packages are used to apply themes to style our web application. For more information, take a look at Appendix, Required Packages. Required packages for this chapter are shown in the following table:

Package	Reason
ggplot2	High-quality graphs
lubridate	Easily transform dates
shiny	Create modern web applications
ggthemr	Apply themes to ggplot2 plots
shinythemes	Apply themes to Shiny applications

Introducing the Shiny application architecture and reactivity

In its simplest form, a Shiny application requires a server and a user interface (UI). These components form the basic architecture behind all Shiny applications. The ui object controls the layout and appearance of your application, and the server function contains the logic needed by the application. If you know how web applications work, you can think...