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]]
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_tables <- function(html) {
# Ensure all tables have class="table"
table <- xml2::xml_find_all(html, ".//table")
xml2::xml_attr(table, "class") <- "table"
invisible()
}
# HTML from markdown/RMarkdown --------------------------------------------
tweak_rmarkdown_html <- function(html, strip_header = FALSE, depth = 1L) {
# Automatically link funtion mentions
tweak_code(html, depth = depth)
tweak_anchors(html, only_contents = FALSE)
# Tweak classes of navbar
toc <- xml2::xml_find_all(html, ".//div[@id='tocnav']//ul")
xml2::xml_attr(toc, "class") <- "nav nav-pills nav-stacked"
# Remove unnused toc
if (strip_header) {
header <- xml2::xml_find_all(html, ".//div[contains(@class, 'page-header')]")
if (length(header) > 0)
xml2::xml_remove(header, free = TRUE)
}
tweak_tables(html)
invisible()
}
tweak_homepage_html <- function(html, strip_header = FALSE) {
first_para <- xml2::xml_find_first(html, "//p")
badges <- first_para %>% xml2::xml_children()
has_badges <- length(badges) > 0 && all(xml2::xml_name(badges) %in% "a")
if (has_badges) {
list <- list_with_heading(badges, "Dev status")
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='sidebar']")
list_html %>%
xml2::xml_children() %>%
purrr::walk(~ xml2::xml_add_child(sidebar, .))
xml2::xml_remove(first_para)
}
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()
}
# code --------------------------------------------------------------------
# Assumes generated with rmarkdown (i.e. knitr + pandoc)
tweak_code <- function(x, depth = 0L) {
stopifnot(inherits(x, "xml_node"))
scoped_file_context(depth = depth)
# <pre class="sourceCode r">
x %>%
xml2::xml_find_all(".//pre[contains(@class, 'r')]") %>%
purrr::map(tweak_pre_node)
# Needs to second so have all packages loaded in chunks
# <code> with no children (just text)
x %>%
xml2::xml_find_all(".//code[count(*) = 0]") %>%
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()
}
# Process in order, because attaching a package affects later code chunks
tweak_pre_node <- function(node, ...) {
# Register attached packages
text <- node %>% xml2::xml_text()
expr <- tryCatch(parse(text = text), error = function(e) NULL)
packages <- extract_package_attach(expr)
register_attached_packages(packages)
# Find nodes with class kw and look backward to see if its qualified
span <- node %>% xml2::xml_find_all(".//span[@class = 'kw']")
pkg <- span %>% purrr::map_chr(find_qualifier)
has_pkg <- !is.na(pkg)
# Extract text and link
text <- span %>% xml2::xml_text()
href <- chr_along(text)
href[has_pkg] <- purrr::map2_chr(text[has_pkg], pkg[has_pkg], href_topic_remote)
href[!has_pkg] <- purrr::map_chr(text[!has_pkg], href_topic_local)
has_link <- !is.na(href)
span[has_link] %>%
xml2::xml_contents() %>%
xml2::xml_replace("a", href = href[has_link], text[has_link])
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_)
}
rematch::re_match("([[:alnum:]]+)$", xml2::xml_text(qual))[, 2]
}
# Helper for testing
autolink_html_ <- function(x, ...) {
x <- paste0("<html><body>", x, "</body></html>")
xml <- xml2::read_html(x)
tweak_code(xml, ...)
xml %>%
xml2::xml_find_first(".//body[1]") %>%
xml2::xml_children() %>%
as.character()
}
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