discourse/lib/cooked_post_processor.rb

170 lines
4.5 KiB
Ruby

# Post processing that we can do after a post has already been cooked. For
# example, inserting the onebox content, or image sizes.
require_dependency 'oneboxer'
class CookedPostProcessor
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
return unless @doc.present?
post_process_images
post_process_oneboxes
end
def post_process_images
images = @doc.search("img")
return unless images.present?
images.each do |img|
# keep track of the original src
src = img['src']
# make sure the src is absolute (when working with locally uploaded files)
img['src'] = Discourse.base_url_no_prefix + img['src'] if img['src'] =~ /^\/[^\/]/
if src.present?
# make sure the img has both width and height attributes
update_dimensions!(img)
# retrieve the associated upload, if any
upload = get_upload_from_url(img['src'])
if upload.present?
# update reverse index
associate_to_post upload
# create a thumbnail
upload.create_thumbnail!
# optimize image
img['src'] = optimize_image(img)
# lightbox treatment
convert_to_link!(img, upload.thumbnail_url)
else
convert_to_link!(img)
end
# 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'
if @post.post_number == 1
img = images.first
@post.topic.update_column :image_url, img['src'] if img['src'].present?
end
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 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.to_s
img['height'] = h.to_s
@dirty = true
end
end
def get_upload_from_url(url)
if Upload.has_been_uploaded?(url) && m = Upload.uploaded_regex.match(url)
Upload.where("id = ?", m[:upload_id]).first
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)
return img["src"]
# 1) optimize using image_optim
# 2) .png vs. .jpg
end
def convert_to_link!(img, thumbnail=nil)
src = img["src"]
width, height = img["width"].to_i, img["height"].to_i
return unless src.present? && width > SiteSetting.auto_link_images_wider_than
original_width, original_height = get_size(src)
return unless original_width.to_i > width && original_height.to_i > height
parent = img.parent
while parent
return if parent.name == "a"
break unless parent.respond_to? :parent
parent = parent.parent
end
# not a hyperlink so we can apply
img['src'] = thumbnail if thumbnail
a = Nokogiri::XML::Node.new "a", @doc
img.add_next_sibling(a)
a["href"] = src
a["class"] = "lightbox"
a.add_child(img)
@dirty = true
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)
uri = get_image_uri(url)
return unless uri
w, h = get_size(url)
ImageSizer.resize(w, h) if w && h
end
def get_size(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 get_image_uri(url)
uri = URI.parse(url)
uri if %w(http https).include?(uri.scheme)
end
def dirty?
@dirty
end
def html
@doc.try(:to_html)
end
end