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
: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).
:img_attrs (optional) - Attributes for generated img tag. E.g. Pass { "draggble" => true, "height" => nil } to set draggable attribute to "true" and clear height attribute of generated img tag.

Constant Summary collapse

DEFAULT_IGNORED_ANCESTOR_TAGS = 
%w(pre code tt).freeze

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_path(name) ⇒ Object

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.



63
64
65
66
67
68
69
 
# File 'lib/html/pipeline/emoji_filter.rb', line 63

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

#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.



55
56
57
 
# File 'lib/html/pipeline/emoji_filter.rb', line 55

def asset_root
  context[:asset_root]
end

#call ⇒ Object 



22
23
24
25
26
27
28
29
30
31
32
 
# File 'lib/html/pipeline/emoji_filter.rb', line 22

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

#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.



45
46
47
48
49
 
# File 'lib/html/pipeline/emoji_filter.rb', line 45

def emoji_image_filter(text)
  text.gsub(emoji_pattern) do |match|
    emoji_image_tag($1)
  end
end

#validate ⇒ Object

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



36
37
38
 
# File 'lib/html/pipeline/emoji_filter.rb', line 36

def validate
  needs :asset_root
end