Class: HTML::Pipeline::EmojiFilter

Inherits:
Filter
  • Object
show all
Defined in:
lib/html/pipeline/emoji_filter.rb

Overview

HTML filter that replaces :emoji: with images.

Context:

:asset_root (required) - base url to link to emoji sprite

Constant Summary collapse

EmojiPattern =

Build a regexp that matches all valid :emoji: names.

/:(#{Emoji.names.map { |name| Regexp.escape(name) }.join('|')}):/

Instance Attribute Summary

Attributes inherited from Filter

#context, #result

Instance Method Summary collapse

Methods inherited from Filter

#base_url, call, #current_user, #doc, #has_ancestor?, #html, #initialize, #needs, #parse_html, #repository, to_document, to_html

Constructor Details

This class inherits a constructor from HTML::Pipeline::Filter

Instance Method Details

#asset_root ⇒ Object

The base url to link emoji sprites

Raises ArgumentError if context option has not been provided. Returns the context’s asset_root.



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# File 'lib/html/pipeline/emoji_filter.rb', line 53

def asset_root
  context[:asset_root]
end

#call ⇒ Object 



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# File 'lib/html/pipeline/emoji_filter.rb', line 17

def call
  doc.search('text()').each do |node|
    content = node.to_html
    next if !content.include?(':')
    next if has_ancestor?(node, %w(pre code))
    html = emoji_image_filter(content)
    next if html == content
    node.replace(html)
  end
  doc
end

#emoji_image_filter(text) ⇒ Object

Replace :emoji: with corresponding images.

text - String text to replace :emoji: in.

Returns a String with :emoji: replaced with images.



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# File 'lib/html/pipeline/emoji_filter.rb', line 40

def emoji_image_filter(text)
  return text unless text.include?(':')

  text.gsub EmojiPattern do |match|
    name = $1
    "<img class='emoji' title=':#{name}:' alt=':#{name}:' src='#{File.join(asset_root, "emoji", "#{name}.png")}' height='20' width='20' align='absmiddle' />"
  end
end

#validate ⇒ Object

Implementation of validate hook. Errors should raise exceptions or use an existing validator.



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# File 'lib/html/pipeline/emoji_filter.rb', line 31

def validate
  needs :asset_root
end