# 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?("#{original_node.css("blockquote").inner_html}

" 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( "

#{CGI.escapeHTML(display_src)}

", ), ) 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 strip_hashtag_link_icons 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) 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 strip_hashtag_link_icons @fragment .search(".hashtag-cooked") .each do |hashtag| hashtag.children.each(&:remove) hashtag.add_child(<<~HTML) ##{hashtag["data-slug"]} 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