Generate a random fontawesome icon for quick prototyping. Can also use a "term" to limit random icon choice to a specific category.

random_icon.R

library(jsonlite)
library(fontawesome)
library(rlang)
library(purrr)
library(tidyverse)

# https://kapeli.com/cheat_sheets/Font_Awesome.docset/Contents/Resources/Documents/index
# https://github.com/rstudio/fontawesome/blob/master/R/fa.R

url <- "https://raw.githubusercontent.com/FortAwesome/Font-Awesome/master/metadata/icons.json"

fa_list <- jsonlite::fromJSON(url)

icon_table <- fontawesome:::fa_tbl %>% 
  dplyr::mutate(
    terms = (
      purrr::map_chr(
        icon_table$name,
        function(name) {
          hold <- fa_list[[name]][["search"]][["terms"]]
          if (length(hold) == 0) return(NA_character_)
          knitr::combine_words(hold)
        })
    ),
    terms = dplyr::coalesce(terms, "Unknown")
  )

#' Random Icon Generator
#' 
#' This function generates a random `fontawesome` icon for quick usage 
#' while prototyping shiny apps. 
#'
#' @param term (optional) term to limit number of icons available to a specific 
#'   category. For a list of available terms see the [icon_table].
#'
#' @return An HTML icon element returned via [shiny::icon()]
#' @export
#'
#' @examples
#' random_icon() # should display in R Viewer
#' random_icon("animal")
#' shiny::fluidRow(random_icon())
random_icon <- function(term = NULL,
                        class = NULL) {
  
  icon_tbl <- icon_table # fontawesome:::fa_tbl
  
  if (!is.null(term)) {
    filt <- icon_tbl %>%
      dplyr::filter(grepl(term, .data$terms))
    if (nrow(filt) == 0) {
      warning(term, " not found. Reverting to full library of icons.")
      icon_tbl <- icon_tbl
    } else {
      icon_tbl <- filt
    }
    
  }
  
  row <- runif(n = 1, min = 0, max = nrow(icon_tbl) + 1) %>% trunc()
  
  out <- icon_tbl[row, "name"]
  message("Random Icon Selected: ", out)
  shiny::icon(out, class = class)
  
}

random_icon()
random_icon("file")

terms <- icon_table$terms %>%
  gsub(",", "", .) %>%
  stringr::str_split(., pattern = " ") %>%
  purrr::flatten_chr() %>%
  unique() %>%
  sort()

# HTML text
paste0('<i class="fa fa-', out, '"></i>')

# return as HTML/SVG
htmltools::HTML(icon_tbl[row, "svg"])

# return as PNG
fontawesome::fa_png()

# shiny::icon
# function (name, class = NULL, lib = "font-awesome") 
# {
#   prefixes <- list(`font-awesome` = "fa", glyphicon = "glyphicon")
#   prefix <- prefixes[[lib]]
#   if (is.null(prefix)) {
#     stop("Unknown font library '", lib, "' specified. Must be one of ", 
#          paste0("\"", names(prefixes), "\"", collapse = ", "))
#   }
#   iconClass <- ""
#   if (!is.null(name)) {
#     prefix_class <- prefix
#     if (prefix_class == "fa" && name %in% font_awesome_brands) {
#       prefix_class <- "fab"
#     }
#     iconClass <- paste0(prefix_class, " ", prefix, 
#                         "-", name)
#   }
#   if (!is.null(class)) 
#     iconClass <- paste(iconClass, class)
#   iconTag <- tags$i(class = iconClass)
#   if (lib == "font-awesome") {
#     htmlDependencies(iconTag) <- htmlDependency("font-awesome", 
#                                                 "5.13.0", "www/shared/fontawesome", package = "shiny", 
#                                                 stylesheet = c("css/all.min.css", "css/v4-shims.min.css"))
#   }
#   htmltools::browsable(iconTag)
# }
# <bytecode: 0x000001f5fb68eeb0>
#   <environment: namespace:shiny>


# library(knitr)
# 
# 
# reverse_words <- purrr::negate(~ knitr::combine_words)
# 
# reverse_words("a, b, c, and d")