R/script.R

In r2d3: Interface to 'D3' Visualizations

# Prepares a D3 script to be embedable into a widget
script_wrap <- function(deps, script, container) {
  deps_contents <- script_read(deps)
  script_contents <- script_read(script)
  
  if (is.character(script_contents) && length(script_contents) > 1)
    script_contents <- paste(script_contents, collapse = "\n")
  
  script_contents <- paste(
    # some libraries expect the container to be created from the extended d3 object.
    container, " = d3.select(", container, ".node());",
    "\n",
    script_contents,
    sep = ""
  )
  
  paste(
    "var d3Script = function(d3, r2d3, data, ", container, ", width, height, options, theme, console) {",
    "\n",
    # some libraries expect d3 to be accessible as this.d3
    "this.d3 = d3;",
    "\n",
    deps_contents,
    "\n",
    script_contents,
    "\n",
    "};",
    sep = ""
  )
}


script_read <- function(script) {
  # Make sure we can properly resolve the scripts as files. If we can't, because
  # none were passed or because the script was just in-lined, then just return
  # the scripts back to the caller
  unresolvable_script_paths <- is.null(script) ||
    length(script) == 0 ||
    any(!file.exists(script))
  
  if (unresolvable_script_paths) {
    return(script)
  }

  paste(
    sapply(
      script,
      function(e) paste(
        c(
          paste("/* R2D3 Source File: ", e, "*/"),
          readLines(e, warn = FALSE)
        ), collapse = "\n"
      )
    ),
    collapse = "\n\n"
  )
}