Mastering Shiny

Preface

What Is Shiny?

If you’ve never used Shiny before, welcome! Shiny is an R package that allows you to easily create rich, interactive web apps. Shiny allows you to take your work in R and expose it via a web browser so that anyone can use it. Shiny makes you look awesome by making it easy to produce polished web apps with a minimum amount of pain.

In the past, creating web apps was hard for most R users because:

• You need a deep knowledge of web technologies like HTML, CSS, and JavaScript.

• Making complex interactive apps requires careful analysis of interaction flows to make sure that when an input changes, only the related outputs are updated.

Shiny makes it significantly easier for the R programmer to create web apps by:

• Providing a carefully curated set of user interface (UI for short) functions that generate the HTML, CSS, and JavaScript needed for common tasks. This means that you don’t need to know the details of HTML/CSS/JavaScript until you want to go beyond the basics that Shiny provides for you.

• Introducing a new style of programming called reactive programming, which automatically tracks the dependencies of pieces of code. This means that whenever an input changes, Shiny can automatically figure out how to do the smallest amount of work to update all the related outputs.

People use Shiny to:

• Create dashboards that track important high-level performance indicators while facilitating drill-down into metrics that need more investigation.

• Replace hundreds ...