discourse/lib/cooked_post_processor.rb

221 lines
6.0 KiB
Ruby

# Post processing that we can do after a post has already been cooked.
# For example, inserting the onebox content, or image sizes/thumbnails.
require_dependency 'oneboxer'
class CookedPostProcessor
include ActionView::Helpers::NumberHelper
def initialize(post, opts={})
@dirty = false
@opts = opts
@post = post
@doc = Nokogiri::HTML::fragment(post.cooked)
@size_cache = {}
@has_been_uploaded_cache = {}
end
def post_process
post_process_images
post_process_oneboxes
end
def post_process_images
images = extract_images
return if images.blank?
images.each do |img|
if img['src'].present?
# keep track of the original src
src = img['src']
# make sure the src is absolute (when working with locally uploaded files)
img['src'] = relative_to_absolute(src)
# make sure the img has proper width and height attributes
update_dimensions!(img)
# retrieve the associated upload, if any
if upload = Upload.get_from_url(img['src'])
# update reverse index
associate_to_post(upload)
end
# lightbox treatment
convert_to_link!(img, upload)
# mark the post as dirty whenever the src has changed
@dirty |= src != img['src']
end
end
# Extract the first image from the first post and use it as the 'topic image'
extract_topic_image(images)
end
def post_process_oneboxes
args = { post_id: @post.id }
args[:invalidate_oneboxes] = true if @opts[:invalidate_oneboxes]
# bake onebox content into the post
result = Oneboxer.apply(@doc) do |url, element|
Oneboxer.onebox(url, args)
end
# mark the post as dirty whenever a onebox as been baked
@dirty |= result.changed?
end
def extract_images
# do not extract images inside a onebox or a quote
@doc.css("img") - @doc.css(".onebox-result img") - @doc.css(".quote img")
end
def relative_to_absolute(src)
if src =~ /\A\/[^\/]/
Discourse.base_url_no_prefix + src
else
src
end
end
def update_dimensions!(img)
return if img['width'].present? && img['height'].present?
w, h = get_size_from_image_sizes(img['src'], @opts[:image_sizes]) || image_dimensions(img['src'])
if w && h
img['width'] = w
img['height'] = h
@dirty = true
end
end
def associate_to_post(upload)
return if PostUpload.where(post_id: @post.id, upload_id: upload.id).count > 0
PostUpload.create({ post_id: @post.id, upload_id: upload.id })
rescue ActiveRecord::RecordNotUnique
# do not care if it's already associated
end
def optimize_image!(img)
# TODO
# 1) optimize using image_optim
# 2) .png vs. .jpg (> 1.5x)
end
def convert_to_link!(img, upload=nil)
src = img["src"]
return unless src.present?
width, height = img["width"].to_i, img["height"].to_i
original_width, original_height = get_size(src)
return if original_width.to_i <= width && original_height.to_i <= height
return if original_width.to_i <= SiteSetting.max_image_width
return if is_a_hyperlink(img)
if upload
# create a thumbnail
upload.create_thumbnail!
# optimize image
# TODO: optimize_image!(img)
end
add_lightbox!(img, original_width, original_height, upload)
@dirty = true
end
def is_a_hyperlink(img)
parent = img.parent
while parent
return if parent.name == "a"
break unless parent.respond_to? :parent
parent = parent.parent
end
end
def add_lightbox!(img, original_width, original_height, upload=nil)
# first, create a div to hold our lightbox
lightbox = Nokogiri::XML::Node.new("div", @doc)
img.add_next_sibling(lightbox)
lightbox.add_child(img)
# then, the link to our larger image
a = Nokogiri::XML::Node.new("a", @doc)
img.add_next_sibling(a)
a["href"] = img['src']
a["class"] = "lightbox"
a.add_child(img)
# replace the image by its thumbnail
img['src'] = upload.thumbnail_url if upload && upload.has_thumbnail?
# then, some overlay informations
meta = Nokogiri::XML::Node.new("div", @doc)
meta["class"] = "meta"
img.add_next_sibling(meta)
filename = get_filename(upload, img['src'])
informations = "#{original_width}x#{original_height}"
informations << " | #{number_to_human_size(upload.filesize)}" if upload
meta.add_child create_span_node("filename", filename)
meta.add_child create_span_node("informations", informations)
meta.add_child create_span_node("expand")
end
def get_filename(upload, src)
return File.basename(src) unless upload
return upload.original_filename unless upload.original_filename =~ /^blob(\.png)?$/i
return I18n.t('upload.pasted_image_filename')
end
def create_span_node(klass, content=nil)
span = Nokogiri::XML::Node.new("span", @doc)
span.content = content if content
span['class'] = klass
span
end
def extract_topic_image(images)
if @post.post_number == 1
img = images.first
@post.topic.update_column :image_url, img['src'] if img['src'].present?
end
end
def get_size_from_image_sizes(src, image_sizes)
if image_sizes.present?
if dim = image_sizes[src]
ImageSizer.resize(dim['width'], dim['height'])
end
end
end
# Retrieve the image dimensions for a url
def image_dimensions(url)
w, h = get_size(url)
ImageSizer.resize(w, h) if w && h
end
def get_size(url)
# make sure s3 urls have a scheme (otherwise, FastImage will fail)
url = "http:" + url if Upload.is_on_s3?(url)
return unless is_valid_image_uri?(url)
# we can *always* crawl our own images
return unless SiteSetting.crawl_images? || Upload.has_been_uploaded?(url)
@size_cache[url] ||= FastImage.size(url)
rescue Zlib::BufError # FastImage.size raises BufError for some gifs
end
def is_valid_image_uri?(url)
uri = URI.parse(url)
%w(http https).include? uri.scheme
rescue URI::InvalidURIError
end
def dirty?
@dirty
end
def html
@doc.try(:to_html)
end
end