# Tag level tweaks --------------------------------------------------------
tweak_anchors <- function(html, only_contents = TRUE) {
if (only_contents) {
sections <- xml2::xml_find_all(html, ".//div[@class='contents']//div[@id]")
} else {
sections <- xml2::xml_find_all(html, "//div[@id]")
}
if (length(sections) == 0)
return()
# Update anchors: dot in the anchor breaks scrollspy
anchor <- sections %>%
xml2::xml_attr("id") %>%
gsub(".", "-", ., fixed = TRUE)
purrr::walk2(sections, anchor, ~ (xml2::xml_attr(.x, "id") <- .y))
# Update href of toc anchors , use "-" instead "."
toc_nav <- xml2::xml_find_all(html, ".//div[@id='tocnav']//a")
hrefs <- toc_nav %>%
xml2::xml_attr("href") %>%
gsub(".", "-", ., fixed = TRUE)
purrr::walk2(toc_nav, hrefs, ~ (xml2::xml_attr(.x, "href") <- .y))
headings <- xml2::xml_find_first(sections, ".//h1|h2|h3|h4|h5")
has_heading <- !is.na(xml2::xml_name(headings))
for (i in seq_along(headings)[has_heading]) {
# Insert anchor in first element of header
heading <- headings[[i]]
if (length(xml2::xml_contents(heading)) == 0) {
# skip empty headings
next
}
xml2::xml_attr(heading, "class") <- "hasAnchor"
xml2::xml_add_sibling(
xml2::xml_contents(heading)[[1]],
"a", href = paste0("#", anchor[[i]]),
class = "anchor",
.where = "before"
)
}
invisible()
}
tweak_md_links <- function(html) {
links <- xml2::xml_find_all(html, ".//a")
if (length(links) == 0)
return()
hrefs <- xml2::xml_attr(links, "href")
needs_tweak <- grepl("\\.md$", hrefs) & xml2::url_parse(hrefs)$scheme == ""
fix_links <- function(x) {
x <- gsub("\\.md$", ".html", x)
x <- gsub("\\.github/", "", x)
x
}
if (any(needs_tweak)) {
purrr::walk2(
links[needs_tweak],
fix_links(hrefs[needs_tweak]),
xml2::xml_set_attr,
attr = "href"
)
}
invisible()
}
tweak_tables <- function(html) {
# Ensure all tables have class="table"
table <- xml2::xml_find_all(html, ".//table")
if (length(table) != 0) {
existing <- xml2::xml_attrs(table, "class")
tweaked <- purrr::map(existing, prepend_class)
xml2::xml_attrs(table, "class") <- tweaked
}
invisible()
}
prepend_class <- function(x, class = "table") {
if (!('class' %in% names(x))) {
c(class = class)
} else {
c(class = paste(class, x[["class"]]))
}
}
# Autolinking -------------------------------------------------------------
# Assumes generated with rmarkdown (i.e. knitr + pandoc)
tweak_code <- function(x) {
stopifnot(inherits(x, "xml_node"))
# <pre class="sourceCode r">
x %>%
xml2::xml_find_all(".//pre[contains(@class, 'sourceCode r')]") %>%
purrr::map(tweak_pre_node)
# Identify <code> with no children (just text), and are not ancestors of a
# header
x %>%
xml2::xml_find_all(
paste0(
".//code[count(*) = 0 and ",
"not(ancestor::h1|ancestor::h2|ancestor::h3|ancestor::h4|ancestor::h5) and ",
"not(ancestor::div[contains(@id, 'tocnav')])]"
)
) %>%
tweak_code_nodeset()
invisible()
}
tweak_code_nodeset <- function(nodes, ...) {
text <- nodes %>% xml2::xml_text()
href <- text %>% purrr::map_chr(href_string, ...)
has_link <- !is.na(href)
nodes[has_link] %>%
xml2::xml_contents() %>%
xml2::xml_replace("a", href = href[has_link], text[has_link])
invisible()
}
tweak_pre_node <- function(node, ...) {
text <- xml2::xml_text(node)
html <- highlight_text(text)
if (is.null(html)) {
return()
}
html <- paste0("<pre class='r'>", html, "</pre>")
xml2::xml_replace(node, xml2::read_html(html))
invisible()
}
find_qualifier <- function(node) {
prev <- rev(xml2::xml_find_all(node, "./preceding-sibling::node()"))
if (length(prev) < 2) {
return(NA_character_)
}
colons <- prev[[1]]
if (xml2::xml_name(colons) != "span" || xml2::xml_text(colons) != "::") {
return(NA_character_)
}
qual <- prev[[2]]
if (xml2::xml_name(qual) != "text") {
return(NA_character_)
}
rematch2::re_match(xml2::xml_text(qual), "([[:alnum:]]+)$")[[".match"]]
}
# File level tweaks --------------------------------------------
tweak_rmarkdown_html <- function(html, input_path) {
# Automatically link funtion mentions
tweak_code(html)
tweak_anchors(html, only_contents = FALSE)
tweak_md_links(html)
# Tweak classes of navbar
toc <- xml2::xml_find_all(html, ".//div[@id='tocnav']//ul")
xml2::xml_attr(toc, "class") <- "nav nav-pills nav-stacked"
# Mame sure all images use relative paths
img <- xml2::xml_find_all(html, "//img")
src <- xml2::xml_attr(img, "src")
abs_src <- is_absolute_path(src)
if (any(abs_src)) {
purrr::walk2(
img[abs_src],
path_rel(src[abs_src], input_path),
xml2::xml_set_attr,
attr = "src"
)
}
tweak_tables(html)
invisible()
}
tweak_homepage_html <- function(html, strip_header = FALSE) {
badges <- badges_extract(html)
if (length(badges) > 0) {
list <- sidebar_section("Dev status", badges)
list_div <- paste0("<div>", list, "</div>")
list_html <- list_div %>% xml2::read_html() %>% xml2::xml_find_first(".//div")
sidebar <- html %>% xml2::xml_find_first(".//div[@id='pkgdown-sidebar']")
list_html %>%
xml2::xml_children() %>%
purrr::walk(~ xml2::xml_add_child(sidebar, .))
}
# Always remove dummy page header
header <- xml2::xml_find_all(html, ".//div[contains(@class, 'page-header')]")
if (length(header) > 0)
xml2::xml_remove(header, free = TRUE)
header <- xml2::xml_find_first(html, ".//h1")
if (strip_header) {
xml2::xml_remove(header, free = TRUE)
} else {
page_header_text <- paste0("<div class='page-header'>", header, "</div>")
page_header <- xml2::read_html(page_header_text) %>% xml2::xml_find_first("//div")
xml2::xml_replace(header, page_header)
}
# Fix relative image links
imgs <- xml2::xml_find_all(html, ".//img")
urls <- xml2::xml_attr(imgs, "src")
new_urls <- gsub("^vignettes/", "articles/", urls)
new_urls <- gsub("^man/figures/", "reference/figures/", new_urls)
purrr::map2(imgs, new_urls, ~ (xml2::xml_attr(.x, "src") <- .y))
tweak_tables(html)
invisible()
}
# Mutates `html`, removing the badge container
badges_extract <- function(html) {
# First try specially named element;
x <- xml2::xml_find_first(html, "//div[@id='badges']")
strict <- FALSE
# then try usethis-readme-like paragraph;
if (length(x) == 0) {
# Find start comment, then all elements after
# which are followed by the end comment.
x <- xml2::xml_find_all(html, "
//comment()[contains(., 'badges: start')][1]
/following-sibling::*[following-sibling::comment()[contains(., 'badges: end')]]
")
}
# finally try first paragraph
if (length(x) == 0) {
x <- xml2::xml_find_first(html, "//p")
strict <- TRUE
}
# No paragraph
if (length(x) == 0) {
return(character())
}
# If we guessed the element,
# we only proceed if there is no text
if (strict && any(xml2::xml_text(x, trim = TRUE) != "")) {
return(character())
}
# Proceed if we find image-containing links
badges <- xml2::xml_find_all(x, ".//a[img]")
if (length(badges) == 0) {
return(character())
}
xml2::xml_remove(x)
as.character(badges)
}
badges_extract_text <- function(x) {
xml <- xml2::read_html(x)
badges_extract(xml)
}
# Update file on disk -----------------------------------------------------
update_html <- function(path, tweak, ...) {
html <- xml2::read_html(path, encoding = "UTF-8")
tweak(html, ...)
xml2::write_html(html, path, format = FALSE)
path
}
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.