Class: Banzai::Filter::AttributesFilter

Inherits:
HTML::Pipeline::Filter
  • Object
show all
Defined in:
lib/banzai/filter/attributes_filter.rb

Overview

Looks for attributes that are specified for an element. Follows the basic syntax laid out in github.com/jgm/commonmark-hs/blob/master/commonmark-extensions/test/attributes.md For example,

![](http://example.com/image.jpg){width=50%}

However we currently have the following limitations:

  • only support images

  • only support the ‘width` and `height` attributes

  • attributes can not span multiple lines

  • unsupported attributes are thrown away

Constant Summary collapse

CSS = 
'img'
XPATH = 
Gitlab::Utils::Nokogiri.css_to_xpath(CSS).freeze
ATTRIBUTES_PATTERN = 
%r{\A(?<matched>\{(?<attributes>.{1,100})\})}
WIDTH_HEIGHT_REGEX = 
%r{\A(?<name>height|width)="?(?<size>[\w%]{1,10})"?\z}
VALID_SIZE_REGEX = 
%r{\A\d{1,4}(%|px)?\z}

Instance Method Summary collapse

Instance Method Details

#call ⇒ Object 



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# File 'lib/banzai/filter/attributes_filter.rb', line 23

def call
  doc.xpath(XPATH).each do |img|
    sibling = img.next
    next unless sibling && sibling.text? && sibling.content.first == '{'

    match = sibling.content.match(ATTRIBUTES_PATTERN)
    next unless match && match[:attributes]

    match[:attributes].split(' ').each do |attribute|
      next unless attribute.match?(WIDTH_HEIGHT_REGEX)

      attribute_match = attribute.match(WIDTH_HEIGHT_REGEX)
      img[attribute_match[:name].to_sym] = attribute_match[:size] if valid_size?(attribute_match[:size])
    end

    sibling.content = sibling.content.sub(match[:matched], '')
  end

  doc
end