discourse/lib/email/styles.rb

539 lines
18 KiB
Ruby

# frozen_string_literal: true
#
# HTML emails don't support CSS, so we can use nokogiri to inline attributes based on
# matchers.
#
module Email
class Styles
MAX_IMAGE_DIMENSION = 400
ONEBOX_IMAGE_BASE_STYLE =
"max-height: 80%; max-width: 20%; height: auto; float: left; margin-right: 10px;"
ONEBOX_IMAGE_THUMBNAIL_STYLE = "width: 60px;"
ONEBOX_INLINE_AVATAR_STYLE = "width: 20px; height: 20px; float: none; vertical-align: middle;"
@@plugin_callbacks = []
attr_accessor :fragment
delegate :css, to: :fragment
def initialize(html, opts = nil)
@html = html
@opts = opts || {}
@fragment = Nokogiri::HTML5.parse(@html)
@custom_styles = nil
end
def self.register_plugin_style(&block)
@@plugin_callbacks.push(block)
end
def add_styles(node, new_styles)
existing = node["style"]
if existing.present?
# merge styles
node["style"] = "#{new_styles}; #{existing}"
else
node["style"] = new_styles
end
end
def custom_styles
return @custom_styles unless @custom_styles.nil?
css = EmailStyle.new.compiled_css
@custom_styles = {}
if !css.blank?
# there is a minor race condition here, CssParser could be
# loaded by ::CssParser::Parser not loaded
require "css_parser" unless defined?(::CssParser::Parser)
parser = ::CssParser::Parser.new(import: false)
parser.load_string!(css)
parser.each_selector do |selector, value|
@custom_styles[selector] ||= +""
@custom_styles[selector] << value
end
end
@custom_styles
end
def format_basic
uri = URI(Discourse.base_url)
# Remove SVGs
@fragment.css('svg, img[src$=".svg"]').remove
# images
@fragment
.css("img")
.each do |img|
next if img["class"] == "site-logo"
if (img["class"] && img["class"]["emoji"]) || (img["src"] && img["src"][%r{/_?emoji/}])
img["width"] = img["height"] = 20
else
# use dimensions of original iPhone screen for 'too big, let device rescale'
if img["width"].to_i > (320) || img["height"].to_i > (480)
img["width"] = img["height"] = "auto"
end
end
if img["src"]
# ensure all urls are absolute
img["src"] = "#{Discourse.base_url}#{img["src"]}" if img["src"][%r{^/[^/]}]
# ensure no schemaless urls
img["src"] = "#{uri.scheme}:#{img["src"]}" if img["src"][%r{^//}]
end
end
# add max-width to big images
big_images =
@fragment.css('img[width="auto"][height="auto"]') - @fragment.css("aside.onebox img") -
@fragment.css("img.site-logo, img.emoji")
big_images.each { |img| add_styles(img, "max-width: 100%;") if img["style"] !~ /max-width/ }
# topic featured link
@fragment
.css("a.topic-featured-link")
.each do |e|
e[
"style"
] = "color:#858585;padding:2px 8px;border:1px solid #e6e6e6;border-radius:2px;box-shadow:0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);"
end
# attachments
@fragment
.css("a.attachment")
.each do |a|
# ensure all urls are absolute
a["href"] = "#{Discourse.base_url}#{a["href"]}" if a["href"] =~ %r{^/[^/]}
# ensure no schemaless urls
a["href"] = "#{uri.scheme}:#{a["href"]}" if a["href"] && a["href"].starts_with?("//")
end
end
def onebox_styles
# Links to other topics
style("aside.quote", "padding: 12px 25px 2px 12px; margin-bottom: 10px;")
style("aside.quote div.info-line", "color: #666; margin: 10px 0")
style(
"aside.quote .avatar",
"margin-right: 5px; width:20px; height:20px; vertical-align:middle;",
)
style("aside.quote", "border-left: 5px solid #e9e9e9; background-color: #f8f8f8; margin: 0;")
style(
"blockquote",
"border-left: 5px solid #e9e9e9; background-color: #f8f8f8; margin-left: 0; padding: 12px;",
)
# Oneboxes
style(
"aside.onebox",
"border: 5px solid #e9e9e9; padding: 12px 25px 12px 12px; margin-bottom: 10px;",
)
style("aside.onebox header img.site-icon", "width: 16px; height: 16px; margin-right: 3px;")
style("aside.onebox header a[href]", "color: #222222; text-decoration: none;")
style("aside.onebox .onebox-body", "clear: both")
style("aside.onebox .onebox-body img:not(.onebox-avatar-inline)", ONEBOX_IMAGE_BASE_STYLE)
style("aside.onebox .onebox-body img.thumbnail", ONEBOX_IMAGE_THUMBNAIL_STYLE)
style(
"aside.onebox .onebox-body h3, aside.onebox .onebox-body h4",
"font-size: 1.17em; margin: 10px 0;",
)
style(".onebox-metadata", "color: #919191")
style(".github-info", "margin-top: 10px;")
style(".github-info .added", "color: #090;")
style(".github-info .removed", "color: #e45735;")
style(".github-info div", "display: inline; margin-right: 10px;")
style(".github-icon-container", "float: left;")
style(".github-icon-container *", "fill: #646464; width: 40px; height: 40px;")
style(
".github-body-container",
'font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; margin-top: 1em !important;',
)
style(".onebox-avatar-inline", ONEBOX_INLINE_AVATAR_STYLE)
@fragment.css(".github-body-container .excerpt").remove
@fragment.css("aside.quote blockquote > p").each { |p| p["style"] = "padding: 0;" }
# Convert all `aside.quote` tags to `blockquote`s
@fragment
.css("aside.quote")
.each do |n|
original_node = n.dup
original_node.search("div.quote-controls").remove
blockquote =
(
if original_node.css("blockquote").inner_html.strip.start_with?("<p")
original_node.css("blockquote").inner_html
else
"<p style='padding: 0;'>#{original_node.css("blockquote").inner_html}</p>"
end
)
n.inner_html = original_node.css("div.title").inner_html + blockquote
n.name = "blockquote"
end
# Finally, convert all `aside` tags to `div`s
@fragment.css("aside, article, header").each { |n| n.name = "div" }
# iframes can't go in emails, so replace them with clickable links
@fragment
.css("iframe")
.each do |i|
begin
# sometimes, iframes are blocklisted...
if i["src"].blank?
i.remove
next
end
src_uri =
i["data-original-href"].present? ? URI(i["data-original-href"]) : URI(i["src"])
# If an iframe is protocol relative, use SSL when displaying it
display_src =
"#{src_uri.scheme || "https"}://#{src_uri.host}#{src_uri.path}#{src_uri.query.nil? ? "" : "?" + src_uri.query}#{src_uri.fragment.nil? ? "" : "#" + src_uri.fragment}"
i.replace(
Nokogiri::HTML5.fragment(
"<p><a href='#{src_uri.to_s}'>#{CGI.escapeHTML(display_src)}</a><p>",
),
)
rescue URI::Error
# If the URL is weird, remove the iframe
i.remove
end
end
end
def format_html
correct_first_body_margin
correct_footer_style
correct_footer_style_highlight_first
decorate_hashtags
reset_tables
html_lang = SiteSetting.default_locale.sub("_", "-")
style("html", nil, :lang => html_lang, "xml:lang" => html_lang)
style("body", "line-height: 1.4; text-align:#{Rtl.new(nil).enabled? ? "right" : "left"};")
style("body", nil, dir: Rtl.new(nil).enabled? ? "rtl" : "ltr")
style(
".with-dir",
"text-align:#{Rtl.new(nil).enabled? ? "right" : "left"};",
dir: Rtl.new(nil).enabled? ? "rtl" : "ltr",
)
style("blockquote > :first-child", "margin-top: 0;")
style("blockquote > :last-child", "margin-bottom: 0;")
style("blockquote > p", "padding: 0;")
style(
".with-accent-colors",
"background-color: #{SiteSetting.email_accent_bg_color}; color: #{SiteSetting.email_accent_fg_color};",
)
style("h4", "color: #222;")
style("h3", "margin: 30px 0 10px;")
style("hr", "background-color: #ddd; height: 1px; border: 1px;")
style(
"a",
"text-decoration: none; font-weight: bold; color: #{SiteSetting.email_link_color};",
)
style("ul", "margin: 0 0 0 10px; padding: 0 0 0 20px;")
style("li", "padding-bottom: 10px")
style("div.summary-footer", "color:#666; font-size:95%; text-align:center; padding-top:15px;")
style("span.post-count", "margin: 0 5px; color: #777;")
style("pre", "word-wrap: break-word; max-width: 694px;")
style("code", "background-color: #f9f9f9; padding: 2px 5px;")
style("pre code", "display: block; background-color: #f9f9f9; overflow: auto; padding: 5px;")
style("pre.onebox code", "white-space: normal;")
style("pre code li", "white-space: pre;")
style(
".featured-topic a",
"text-decoration: none; font-weight: bold; color: #{SiteSetting.email_link_color}; line-height:1.5em;",
)
style(
".summary-email",
"-moz-box-sizing:border-box;-ms-text-size-adjust:100%;-webkit-box-sizing:border-box;-webkit-text-size-adjust:100%;box-sizing:border-box;color:#0a0a0a;font-family:Arial,sans-serif;font-size:14px;font-weight:400;line-height:1.3;margin:0;min-width:100%;padding:0;width:100%",
)
style(".previous-discussion", "font-size: 17px; color: #444; margin-bottom:10px;")
style(
".notification-date",
"text-align:right;color:#999999;padding-right:5px;font-family:'lucida grande',tahoma,verdana,arial,sans-serif;font-size:11px",
)
style(
".username",
"font-size:13px;font-family:'lucida grande',tahoma,verdana,arial,sans-serif;text-decoration:none;font-weight:bold",
)
style(".username-link", "color:#{SiteSetting.email_link_color};")
style(".username-title", "color:#777;margin-left:5px;")
style(
".user-title",
"font-size:13px;font-family:'lucida grande',tahoma,verdana,arial,sans-serif;text-decoration:none;margin-left:5px;color: #999;",
)
style(".post-wrapper", "margin-bottom:25px;")
style(".user-avatar", "vertical-align:top;width:55px;")
style(".user-avatar img", nil, width: "45", height: "45")
style("hr", "background-color: #ddd; height: 1px; border: 1px;")
style(".rtl", "direction: rtl;")
style("div.body", "padding-top:5px;")
style(".whisper div.body", "font-style: italic; color: #9c9c9c;")
style(".lightbox-wrapper .meta", "display: none")
style("div.undecorated-link-footer a", "font-weight: normal;")
style(
".mso-accent-link",
"mso-border-alt: 6px solid #{SiteSetting.email_accent_bg_color}; background-color: #{SiteSetting.email_accent_bg_color};",
)
style(
".reply-above-line",
"font-size: 10px;font-family:'lucida grande',tahoma,verdana,arial,sans-serif;color: #b5b5b5;padding: 5px 0px 20px;border-top: 1px dotted #ddd;",
)
onebox_styles
plugin_styles
dark_mode_styles
style(".post-excerpt img", "max-width: 50%; max-height: #{MAX_IMAGE_DIMENSION}px;")
format_custom
end
def format_custom
custom_styles.each { |selector, value| style(selector, value) }
end
# this method is reserved for styles specific to plugin
def plugin_styles
@@plugin_callbacks.each { |block| block.call(@fragment, @opts) }
end
def inline_secure_images(attachments, attachments_index)
stripped_media = @fragment.css("[data-stripped-secure-media], [data-stripped-secure-upload]")
upload_shas = {}
stripped_media.each do |div|
url = div["data-stripped-secure-media"] || div["data-stripped-secure-upload"]
filename = File.basename(url)
filename_bare = filename.gsub(File.extname(filename), "")
sha1 = filename_bare.partition("_").first
upload_shas[url] = sha1
end
uploads = Upload.select(:original_filename, :sha1).where(sha1: upload_shas.values)
stripped_media.each do |div|
upload =
uploads.find do |upl|
upl.sha1 ==
(
upload_shas[div["data-stripped-secure-media"]] ||
upload_shas[div["data-stripped-secure-upload"]]
)
end
next if !upload
if attachments[attachments_index[upload.sha1]]
url = attachments[attachments_index[upload.sha1]].url
onebox_type = div["data-onebox-type"]
style =
if onebox_type
onebox_style =
(
if onebox_type == "avatar-inline"
ONEBOX_INLINE_AVATAR_STYLE
else
ONEBOX_IMAGE_THUMBNAIL_STYLE
end
)
"#{onebox_style} #{ONEBOX_IMAGE_BASE_STYLE}"
else
calculate_width_and_height_style(div)
end
div.add_next_sibling(<<~HTML)
<img src="#{url}" data-embedded-secure-image="true" style="#{style}" />
HTML
div.remove
end
end
end
def to_html
# needs to be before class + id strip because we need to style redacted
# media and also not double-redact already redacted from lower levels
replace_secure_uploads_urls if SiteSetting.secure_uploads?
strip_classes_and_ids
replace_relative_urls
@fragment.to_html
end
def to_s
@fragment.to_s
end
def strip_avatars_and_emojis
@fragment
.search("img")
.each do |img|
next unless img["src"]
if img["src"][/_avatar/]
img.parent["style"] = "vertical-align: top;" if img.parent&.name == "td"
img.remove
end
if img["title"] && img["src"][%r{/_?emoji/}]
img.add_previous_sibling(img["title"] || "emoji")
img.remove
end
end
end
def decorate_hashtags
@fragment
.search(".hashtag-cooked")
.each do |hashtag|
hashtag.children.each(&:remove)
hashtag.add_child(<<~HTML)
<span>##{hashtag["data-slug"]}</span>
HTML
end
end
def make_all_links_absolute
site_uri = URI(Discourse.base_url)
@fragment
.css("a")
.each do |link|
begin
link["href"] = "#{site_uri}#{link["href"]}" unless URI(link["href"].to_s).host.present?
rescue URI::Error
# leave it
end
end
end
private
def dark_mode_styles
# When we ship the email template and its styles we strip all css classes so to give our
# dark mode styles we are including in the template a selector we add a data-attr of 'dm=value' to
# the appropriate place
style(
".digest-header, .digest-topic, .digest-topic-title-wrapper, .digest-topic-stats, .popular-post-excerpt",
nil,
dm: "header",
)
style(
".digest-content, .header-popular-posts, .spacer, .popular-post-spacer, .popular-post-meta, .digest-new-header, .digest-new-topic, .body",
nil,
dm: "body",
)
style(".with-accent-colors, .digest-content-header", nil, dm: "body_primary")
style(".digest-topic-body", nil, dm: "topic-body")
style(".summary-footer", nil, dm: "text-color")
style("code, pre code, blockquote", nil, dm: "bg")
end
def replace_relative_urls
forum_uri = URI(Discourse.base_url)
host = forum_uri.host
scheme = forum_uri.scheme
@fragment
.css("[href]")
.each do |element|
href = element["href"]
element["href"] = "#{scheme}:#{href}" if href.start_with?("\/\/#{host}")
end
end
def calculate_width_and_height_style(div)
width = div["data-width"]
height = div["data-height"]
if width.present? && height.present? && height.to_i < MAX_IMAGE_DIMENSION &&
width.to_i < MAX_IMAGE_DIMENSION
"width: #{width}px; height: #{height}px;"
else
"max-width: 50%; max-height: #{MAX_IMAGE_DIMENSION}px;"
end
end
def replace_secure_uploads_urls
# strip again, this can be done at a lower level like in the user
# notification template but that may not catch everything
PrettyText.strip_secure_uploads(@fragment)
style(
"div.secure-upload-notice",
"border: 5px solid #e9e9e9; padding: 5px; display: inline-block;",
)
style("div.secure-upload-notice a", "color: #{SiteSetting.email_link_color}")
end
def correct_first_body_margin
@fragment.css("div.body p").each { |element| element["style"] = "margin-top:0; border: 0;" }
end
def correct_footer_style
@fragment
.css(".footer")
.each do |element|
element["style"] = "color:#666;"
element.css("a").each { |inner| inner["style"] = "color:#666;" }
end
end
def correct_footer_style_highlight_first
footernum = 0
@fragment
.css(".footer.highlight")
.each do |element|
linknum = 0
element
.css("a")
.each do |inner|
# we want the first footer link to be specially highlighted as IMPORTANT
if footernum == (0) && linknum == (0)
bg_color = SiteSetting.email_accent_bg_color
inner[
"style"
] = "background-color: #{bg_color}; color: #{SiteSetting.email_accent_fg_color}; border-top: 4px solid #{bg_color}; border-right: 6px solid #{bg_color}; border-bottom: 4px solid #{bg_color}; border-left: 6px solid #{bg_color}; display: inline-block; font-weight: bold;"
end
return
end
return
end
end
def strip_classes_and_ids
@fragment
.css("*")
.each do |element|
element.delete("class")
element.delete("id")
end
end
def reset_tables
style("table", nil, cellspacing: "0", cellpadding: "0", border: "0")
end
def style(selector, style, attribs = {})
@fragment
.css(selector)
.each do |element|
add_styles(element, style) if style
attribs.each { |k, v| element[k] = v }
end
end
end
end