Shiny app as package: css & all www/ directory stuff

Question

I'm trying to convert a Shiny app into an R package and I am having trouble with all things regarding the www directory as well as "loose" files.

My shiny app works perfectly but when I try to "package it", it doesn't work.

My shiny app directory:

+---my_shiny
|   +---app.R
|   +---utils.R
|   +---www
|       +---style.css
|       +---icon1.png
|       +---icon2.png
|       +---icon3.png
|       +---font.ttf

My code starts like this:

library(hrbrthemes)
library(tidyverse)
library(plotly)

source(here::here("utils.R"))

theme_set(theme_personalized())
update_geom_defaults("text", list(family = theme_get()$text$family))

ui <- navbarPage(
  "Example",
  id = "navbar",
  theme = "style.css",

Now I down't know how to convert it into a package where I can call myapp::appdemo() and it deploys my app.

+---myapp
|   +---DESCRIPTION
|   +---NAMESPACE  
|   +---R
|       +---appdemo.R
|   +---inst
|       +---shiny/
|           +---app.R
|           +---utils.R
|           +---style.css
|           +---icon1.png
|           +---icon2.png
|           +---icon3.png
|           +---font.ttf

But it doesn't work and I don't know how to make it to.

Answer 1

I reverse-engineered the approach used by the {golem} framework to find a method which seems to work:

• Everything which you would normally put in www should now go in inst/app/www. In package development, the inst folder is used for arbitrary additional files that you want include in your package.

• Add inst/app/www as a 'resource path' as follows:

  resources <- system.file("app/www", package = "my-package-name")
  addResourcePath("www", resources)
  

• Use the following in your app's UI to embed the resources:

  tags$head(
  
    # Javascript resources
    htmltools::htmlDependency(
      name = "resources",
      version = "0.0.1",
      src = resources,
      script = list.files(resources, pattern = "\\.js$", recursive = TRUE),
      package = NULL,
      all_files = TRUE
    ),
  
    # CSS resources
    lapply(
      list.files(resources, pattern = "\\.css$", recursive = TRUE),
      function(x) tags$link(href = file.path("www", x), rel = "stylesheet")
    )
  
  )
  

EDIT

I've been testing this on a package and the above no longer seems to work when the package is installed (although it works with devtools::load_all()).

To fix, you need to add resources in the package's call to .onLoad(), which should typically live in R/zzz.R:

# R/zzz.R

.onLoad <- function(libname, pkgname) {
    resources <- system.file("app/www", package = "my-package-name")
    addResourcePath("www", resources)
}