From 5eea47c8d6aaf34de26738c989b64857694b8b06 Mon Sep 17 00:00:00 2001 From: Ted Kulp Date: Sun, 4 Sep 2011 09:56:27 -0400 Subject: [PATCH] Added post_filters plugin Plugins that extend PostFilter will get three additional methods: pre_render, post_render and post_write. These will be called when every page or post is processed and allows for the plugin to modify the post/page object directly to modify the output beyond what can be done with just markup. --- plugins/post_filters.rb | 176 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 176 insertions(+) create mode 100644 plugins/post_filters.rb diff --git a/plugins/post_filters.rb b/plugins/post_filters.rb new file mode 100644 index 0000000..0862680 --- /dev/null +++ b/plugins/post_filters.rb @@ -0,0 +1,176 @@ +module Jekyll + + # Extended plugin type that allows the plugin + # to be called on varous callback methods. + # + # Examples: + # https://github.com/tedkulp/octopress/blob/master/plugins/post_metaweblog.rb + # https://github.com/tedkulp/octopress/blob/master/plugins/post_twitter.rb + class PostFilter < Plugin + + #Called before post is sent to the converter. Allows + #you to modify the post object before the converter + #does it's thing + def pre_render(post) + end + + #Called after the post is rendered with the converter. + #Use the post object to modify it's contents before the + #post is inserted into the template. + def post_render(post) + end + + #Called after the post is written to the disk. + #Use the post object to read it's contents to do something + #after the post is safely written. + def post_write(post) + end + end + + # Monkey patch for the Jekyll Site class. For the original class, + # see: https://github.com/mojombo/jekyll/blob/master/lib/jekyll/site.rb + class Site + + # Instance variable to store the various post_filter + # plugins that are loaded. + attr_accessor :post_filters + + # Instantiates all of the post_filter plugins. This is basically + # a duplication of the other loaders in Site#setup. + def load_post_filters + self.post_filters = Jekyll::PostFilter.subclasses.select do |c| + !self.safe || c.safe + end.map do |c| + c.new(self.config) + end + end + end + + # Monkey patch for the Jekyll Post class. For the original class, + # see: https://github.com/mojombo/jekyll/blob/master/lib/jekyll/post.rb + class Post + + # Copy the #write method to #old_write, so we can redefine #write + # method. + alias_method :old_write, :write + + # Write the generated post file to the destination directory. It + # then calls any post_write methods that may exist. + # +dest+ is the String path to the destination dir + # + # Returns nothing + def write(dest) + old_write(dest) + post_write if respond_to?(:post_write) + end + end + + # Monkey patch for the Jekyll Page class. For the original class, + # see: https://github.com/mojombo/jekyll/blob/master/lib/jekyll/page.rb + class Page + + # Copy the #write method to #old_write, so we can redefine #write + # method. + alias_method :old_write, :write + + # Write the generated post file to the destination directory. It + # then calls any post_write methods that may exist. + # +dest+ is the String path to the destination dir + # + # Returns nothing + def write(dest) + old_write(dest) + post_write if respond_to?(:post_write) + end + end + + # Monkey patch for the Jekyll Convertible module. For the original class, + # see: https://github.com/mojombo/jekyll/blob/master/lib/jekyll/convertible.rb + module Convertible + + def is_post? + self.class.to_s == 'Jekyll::Post' + end + + def is_page? + self.class.to_s == 'Jekyll::Page' + end + + def is_filterable? + is_post? or is_page? + end + + # Call the #pre_render methods on all of the loaded + # post_filter plugins. + # + # Returns nothing + def pre_render + self.site.load_post_filters unless self.site.post_filters + + if self.site.post_filters and is_filterable? + self.site.post_filters.each do |filter| + filter.pre_render(self) + end + end + end + + # Call the #post_render methods on all of the loaded + # post_filter plugins. + # + # Returns nothing + def post_render + if self.site.post_filters and is_filterable? + self.site.post_filters.each do |filter| + filter.post_render(self) + end + end + end + + # Call the #post_write methods on all of the loaded + # post_filter plugins. + # + # Returns nothing + def post_write + if self.site.post_filters and is_filterable? + self.site.post_filters.each do |filter| + filter.post_write(self) + end + end + end + + # Copy the #transform method to #old_transform, so we can + # redefine #transform method. + alias_method :old_transform, :transform + + # Transform the contents based on the content type. Then calls the + # #post_render method if it exists + # + # Returns nothing. + def transform + old_transform + post_render if respond_to?(:post_render) + end + + # Copy the #do_layout method to #old_do_layout, so we can + # redefine #do_layout method. + alias_method :old_do_layout, :do_layout + + # Calls the pre_render method if it exists and then adds any necessary + # layouts to this convertible document. + # + # payload - The site payload Hash. + # layouts - A Hash of {"name" => "layout"}. + # + # Returns nothing. + def do_layout(payload, layouts) + pre_render if respond_to?(:pre_render) + old_do_layout(payload, layouts) + end + + # Returns the full url of the post, including the + # configured url + def full_url + self.site.config['url'] + self.url + end + end +end