developing shiny app as a package and deploying it to shiny server

There is already an accepted answer with many votes, but I'd like to add a few things, so I'll answer myself as well. For more information, you can read my article Supplementing your R package with a Shiny app.

This is the folder structure I use:

- mypacakge
  |- inst
      |- myapp
         |- ui.R
         |- server.R
  |- R
     |- runApp.R
     |- ...
  |- DESCRIPTION
  |- ...

Inside the R/ folder is where I place all the non-shiny code. The code for the shiny app itself lives in inst/. The R/runApp.R file is defined as

#' @export
runExample <- function() {
  appDir <- system.file("myapp", package = "mypackage")
  if (appDir == "") {
    stop("Could not find myapp. Try re-installing `mypackage`.", call. = FALSE)
  }

  shiny::runApp(appDir, display.mode = "normal")
}

(You can see this in action; for example, shinyalert uses this structure for its demo app).

In a comment, you asked how can this be deployed on a shiny server. It's simple, you can simply have a file /srv/shiny-server/myapp.app.R that calls and runs that package (after you've installed the package on the server):

dir <- system.file("myapp", package = "mypackage")
setwd(dir)
shiny::shinyAppDir(".")

(You can see this in action as well, code here)

When I make shiny applications as a stand-alone package, I usually organize the files as so:

In the R directory:

• All of my methods to support the application (these should be exported if they will be used in either the ui.R, server.R, or global.R files)
• A launch_application function

The definition of launch_application is similar to:

launch_application <- function(x, ...)
{
  shiny::runApp(appDir = system.file("application", package = [my_pkg]),
                ...)
}

In the inst directory

• application/server.R
• application/ui.R
• application/global.R

After building and installing the package, I then just need to run

library(my_pkg)
launch_application(...)