discourse/lib/email/styles.rb

408 lines
15 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'][/\/_?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'][/^\/[^\/]/]
# ensure no schemaless urls
img['src'] = "#{uri.scheme}:#{img['src']}" if img['src'][/^\/\//]
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 do |img|
add_styles(img, 'max-width: 100%;') if img['style'] !~ /max-width/
end
# 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
if a['href'] =~ /^\/[^\/]/
a['href'] = "#{Discourse.base_url}#{a['href']}"
end
# ensure no schemaless urls
if a['href'] && a['href'].starts_with?("//")
a['href'] = "#{uri.scheme}:#{a['href']}"
end
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('blockquote', 'border-left: 5px solid #e9e9e9; background-color: #f8f8f8; margin: 0;')
style('blockquote > p', 'padding: 1em;')
# Oneboxes
style('aside.onebox', "border: 5px solid #e9e9e9; padding: 12px 25px 12px 12px;")
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 div', "display: inline; margin-right: 10px;")
style('.onebox-avatar-inline', ONEBOX_INLINE_AVATAR_STYLE)
@fragment.css('aside.quote blockquote > p').each do |p|
p['style'] = 'padding: 0;'
end
# 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 = original_node.css('blockquote').inner_html.strip.start_with?("<p") ? original_node.css('blockquote').inner_html : "<p style='padding: 0;'>#{original_node.css('blockquote').inner_html}</p>"
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 do |n|
n.name = "div"
end
# 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_hilight_first
reset_tables
html_lang = SiteSetting.default_locale.sub("_", "-")
style('html', nil, lang: html_lang, 'xml:lang' => html_lang)
style('body', "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('.with-accent-colors', "background-color: #{SiteSetting.email_accent_bg_color}; color: #{SiteSetting.email_accent_fg_color};")
style('h4', 'color: #222;')
style('h3', 'margin: 15px 0 20px 0;')
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: #f1f1ff; padding: 2px 5px;')
style('pre code', 'display: block; background-color: #f1f1ff; padding: 5px;')
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:Helvetica,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};")
onebox_styles
plugin_styles
style('.post-excerpt img', "max-width: 50%; max-height: #{MAX_IMAGE_DIMENSION}px;")
format_custom
end
def format_custom
custom_styles.each do |selector, value|
style(selector, value)
end
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)
stripped_media = @fragment.css('[data-stripped-secure-media]')
upload_shas = {}
stripped_media.each do |div|
url = div['data-stripped-secure-media']
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 { |upl| upl.sha1 == upload_shas[div['data-stripped-secure-media']] }
next if !upload
original_filename = upload.original_filename
if attachments[original_filename]
url = attachments[original_filename].url
onebox_type = div['data-onebox-type']
style = if onebox_type
onebox_style = onebox_type == "avatar-inline" ? ONEBOX_INLINE_AVATAR_STYLE : ONEBOX_IMAGE_THUMBNAIL_STYLE
"#{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_media_urls if SiteSetting.secure_media?
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'][/\/_?emoji\//]
img.add_previous_sibling(img['title'] || "emoji")
img.remove
end
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 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']
if href.start_with?("\/\/#{host}")
element['href'] = "#{scheme}:#{href}"
end
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_media_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_media(@fragment)
style('div.secure-media-notice', 'border: 5px solid #e9e9e9; padding: 5px; display: inline-block;')
style('div.secure-media-notice a', "color: #{SiteSetting.email_link_color}")
end
def correct_first_body_margin
@fragment.css('div.body p').each do |element|
element['style'] = "margin-top:0; border: 0;"
end
end
def correct_footer_style
@fragment.css('.footer').each do |element|
element['style'] = "color:#666;"
element.css('a').each do |inner|
inner['style'] = "color:#666;"
end
end
end
def correct_footer_style_hilight_first
footernum = 0
@fragment.css('.footer.hilight').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 do |k, v|
element[k] = v
end
end
end
end
end