class HTML::Pipeline::EmojiFilter
HTML filter that replaces :emoji: with images.
Context:
:asset_root (required) - base url to link to emoji sprite :asset_path (optional) - url path to link to emoji sprite. :file_name can be used as a placeholder for the sprite file name. If no asset_path is set "emoji/:file_name" is used. :ignored_ancestor_tags (optional) - Tags to stop the emojification. Node has matched ancestor HTML tags will not be emojified. Default to pre, code, and tt tags. Extra tags please pass in the form of array, e.g., %w(blockquote summary).
Constants
- DEFAULT_IGNORED_ANCESTOR_TAGS
Private Class Methods
# File lib/html/pipeline/emoji_filter.rb, line 90 def self.emoji_names Emoji.all.map(&:aliases).flatten.sort end
Build a regexp that matches all valid :emoji: names.
# File lib/html/pipeline/emoji_filter.rb, line 82 def self.emoji_pattern @emoji_pattern ||= /:(#{emoji_names.map { |name| Regexp.escape(name) }.join('|')}):/ end
Public Instance Methods
The url path to link emoji sprites
:file_name can be used in the #asset_path as a placeholder for the sprite file name. If no #asset_path is set in the context “emoji/:file_name” is used. Returns the context's #asset_path or the default path if no context #asset_path is given.
# File lib/html/pipeline/emoji_filter.rb, line 62 def asset_path(name) if context[:asset_path] context[:asset_path].gsub(":file_name", emoji_filename(name)) else File.join("emoji", emoji_filename(name)) end end
The base url to link emoji sprites
Raises ArgumentError if context option has not been provided. Returns the context's asset_root.
# File lib/html/pipeline/emoji_filter.rb, line 54 def asset_root context[:asset_root] end
# File lib/html/pipeline/emoji_filter.rb, line 21 def call doc.search('.//text()').each do |node| content = node.to_html next unless content.include?(':') next if has_ancestor?(node, ignored_ancestor_tags) html = emoji_image_filter(content) next if html == content node.replace(html) end doc end
Replace :emoji: with corresponding images.
text - String text to replace :emoji: in.
Returns a String with :emoji: replaced with images.
# File lib/html/pipeline/emoji_filter.rb, line 44 def emoji_image_filter(text) text.gsub(emoji_pattern) do |match| emoji_image_tag($1) end end
Implementation of validate hook. Errors should raise exceptions or use an existing validator.
# File lib/html/pipeline/emoji_filter.rb, line 35 def validate needs :asset_root end
Private Instance Methods
# File lib/html/pipeline/emoji_filter.rb, line 94 def emoji_filename(name) Emoji.find_by_alias(name).image_filename end
Build an emoji image tag
# File lib/html/pipeline/emoji_filter.rb, line 73 def emoji_image_tag(name) "<img class='emoji' title=':#{name}:' alt=':#{name}:' src='#{emoji_url(name)}' height='20' width='20' align='absmiddle' />" end
# File lib/html/pipeline/emoji_filter.rb, line 86 def emoji_pattern self.class.emoji_pattern end
# File lib/html/pipeline/emoji_filter.rb, line 77 def emoji_url(name) File.join(asset_root, asset_path(name)) end