R/render.r

Defines functions render_page data_template data_open_graph template_path render_template find_template write_if_different same_contents file_digest made_by_pkgdown check_made_by

Documented in data_template render_page

#' Render page with template
#'
#' Each page is composed of four templates: "head", "header", "content", and
#' "footer". Each of these templates is rendered using the `data`, and
#' then assembled into an overall page using the "layout" template.
#'
#' @param pkg Path to package to document.
#' @param name Name of the template (e.g. "home", "vignette", "news")
#' @param data Data for the template.
#'
#'   This is automatically supplemented with three lists:
#'
#'   * `site`: `title` and path to `root`.
#'   * `yaml`: the `template` key from `_pkgdown.yml`.
#'   * `package`: package metadata including `name` and`version`.
#'
#'   See the full contents by running `data_template()`.
#' @param path Location to create file; relative to destination directory.
#'   If `""` (the default), prints to standard out.
#' @param depth Depth of path relative to base directory.
#' @param quiet If `quiet`, will suppress output messages
#' @export
render_page <- function(pkg = ".", name, data, path = "", depth = NULL, quiet = FALSE) {
  pkg <- as_pkgdown(pkg)

  if (is.null(depth)) {
    depth <- length(strsplit(path, "/")[[1]]) - 1L
  }

  data <- utils::modifyList(data, data_template(pkg, depth = depth))
  data$opengraph <- utils::modifyList(data_open_graph(pkg), data$opengraph %||% list())

  # render template components
  pieces <- c("head", "navbar", "header", "content", "docsearch", "footer")

  templates <- purrr::map_chr(pieces, find_template, name, template_path = template_path(pkg))
  components <- purrr::map(templates, render_template, data = data)
  components <- purrr::set_names(components, pieces)
  components$template <- name

  # render complete layout
  template <- find_template("layout", name, template_path = template_path(pkg))
  rendered <- render_template(template, components)
  write_if_different(pkg, rendered, path, quiet = quiet)
}

#' @export
#' @rdname render_page
data_template <- function(pkg = ".", depth = 0L) {
  pkg <- as_pkgdown(pkg)

  authors <- data_authors(pkg)$main %>%
    purrr::map_chr("name") %>%
    paste(collapse = ", ")

  # Force inclusion so you can reliably refer to objects inside yaml
  # in the moustache templates
  yaml <- purrr::pluck(pkg, "meta", "template", "params", .default = list())
  yaml$.present <- TRUE

  # Look for extra assets to add
  extra <- list()
  extra$css <- path_first_existing(pkg$src_path, "pkgdown", "extra.css")
  extra$js <- path_first_existing(pkg$src_path, "pkgdown", "extra.js")

  print_yaml(list(
    year = strftime(Sys.time(), "%Y"),
    package = list(
      name = pkg$package,
      version = as.character(pkg$version),
      authors = authors
    ),
    development = pkg$development,
    site = list(
      root = up_path(depth),
      title = pkg$meta$title %||% pkg$package
    ),
    dev = pkg$use_dev,
    extra = extra,
    navbar = data_navbar(pkg, depth = depth),
    yaml = yaml
  ))
}

data_open_graph <- function(pkg = ".") {
  pkg <- as_pkgdown(pkg)
  og <- list()
  if (!is.null((pkg$src_path))) {
    site_url <- pkg$meta$url %||% "/"
    if (!grepl("/$", site_url)) {
      site_url <- paste0(site_url, "/")
    }
    og$image <- paste0(site_url, "logo.png")
  }
  og
}

template_path <- function(pkg = ".") {
  pkg <- as_pkgdown(pkg)

  template <- pkg$meta[["template"]]

  if (!is.null(template$path)) {
    path <- path_abs(template$path, start = pkg$src_path)

    if (!file_exists(path))
      stop("Can not find template path ", src_path(path), call. = FALSE)

    path
  } else if (!is.null(template$package)) {
    path_package_pkgdown(template$package, "templates")
  } else {
    character()
  }
}

render_template <- function(path, data) {
  template <- read_lines(path)
  if (length(template) == 0)
    return("")

  whisker::whisker.render(template, data)
}

find_template <- function(type, name, template_path = NULL) {
  paths <- c(
    template_path,
    path_pkgdown("templates")
  )
  names <- c(
    paste0(type, "-", name, ".html"),
    paste0(type, ".html")
  )
  all <- expand.grid(path = paths, name = names)
  locations <- path(all$path, all$name)

  Find(file_exists, locations, nomatch =
    stop("Can't find template for ", type, "-", name, ".", call. = FALSE))
}


write_if_different <- function(pkg, contents, path, quiet = FALSE, check = TRUE) {
  # Almost all uses are relative to destination, except for rmarkdown templates
  full_path <- path_abs(path, start = pkg$dst_path)

  if (check && !made_by_pkgdown(full_path)) {
    if (!quiet) {
      message("Skipping '", path, "': not generated by pkgdown")
    }
    return(FALSE)
  }

  if (same_contents(full_path, contents)) {
    return(FALSE)
  }

  if (!quiet) {
    cat_line("Writing ", dst_path(path))
  }
  write_lines(contents, path = full_path)
  TRUE
}

same_contents <- function(path, contents) {
  if (!file_exists(path))
    return(FALSE)

  new_hash <- digest::digest(contents, serialize = FALSE)

  cur_contents <- paste0(read_lines(path), collapse = "\n")
  cur_hash <-  digest::digest(cur_contents, serialize = FALSE)

  identical(new_hash, cur_hash)
}

file_digest <- function(path) {
  if (file_exists(path)) {
    digest::digest(file = path, algo = "xxhash64")
  } else {
    "MISSING"
  }
}


made_by_pkgdown <- function(path) {
  if (!file_exists(path)) return(TRUE)

  first <- paste(read_lines(path, n = 2), collapse = "\n")
  check_made_by(first)
}

check_made_by <- function(first) {
  if (length(first) == 0L) return(FALSE)
  grepl("<!-- Generated by pkgdown", first, fixed = TRUE)
}
jayhesselberth/pkgdown-search documentation built on May 17, 2019, 9:12 a.m.