Class: Banzai::Filter::HeadingAccessibilityFilter

Inherits:
HTML::Pipeline::Filter
  • Object
show all
Includes:
Concerns::PipelineTimingCheck
Defined in:
lib/banzai/filter/heading_accessibility_filter.rb

Overview

Finds heading anchors and localises the accessible labels on them.

Headings with anchors as generated by our Markdown parser look as follows. Given the input:

“‘markdown ## so cool h2 “`

The HTML generated is (newlines and spaces added for readability):

“‘html <h2 id=“user-content-so-cool-h2” data-sourcepos=“3:1-3:15” dir=“auto”>

so <em data-sourcepos="3:7-3:12">cool</em> h2
<a href="#so-cool-h2" aria-label="Link to heading 'so cool h2'"
   data-heading-content="so cool h2" class="anchor"></a>

</h2> “‘

We use [data-heading-content] to rewrite aria-label in a localisable way.

Constant Summary collapse

SUBANCHOR_CSS = 
'> a:last-child.anchor[aria-label][data-heading-content]'
ANCHOR_CSS = 
%w[h1 h2 h3 h4 h5 h6].map { |h| "#{h} #{SUBANCHOR_CSS}" }.join(', ')
ANCHOR_XPATH = 
Gitlab::Utils::Nokogiri.css_to_xpath(ANCHOR_CSS).freeze

Constants included from Concerns::PipelineTimingCheck

Concerns::PipelineTimingCheck::MAX_PIPELINE_SECONDS

Instance Method Summary collapse

Methods included from Concerns::PipelineTimingCheck

#exceeded_pipeline_max?

Instance Method Details

#call ⇒ Object 



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# File 'lib/banzai/filter/heading_accessibility_filter.rb', line 32

def call
  doc.xpath(ANCHOR_XPATH).each do |node|
    node['aria-label'] = format(_("Link to heading '%{heading}'"), heading: node['data-heading-content'])
  end

  doc
end