Use <code>singleton</code> to wrap contents (tag, text, HTML, or lists) that should
be included in the generated document only once, yet may appear in the
document-generating code more than once. Only the first appearance of the
content (in document order) will be used. Useful for custom components that
have JavaScript files or stylesheets.

singleton

Shiny makes it incredibly easy to build interactive web
    applications with R. Automatic "reactive" binding between inputs and
    outputs and extensive pre-built widgets make it possible to build
    beautiful, responsive, and powerful applications with minimal effort.

singleton: Include Content Only Once

Description

Usage

Arguments