def sanitize_config
      {
        elements: %w(
          p br a span sub sup strong em div hr abbr s
          ul ol li
          blockquote cite pre code kbd
          h1 h2 h3 h4 h5 h6
          img object param del
          table tr td th thead tbody
          figure figcaption
          mark del ins
        ),
        attributes: {
          :all     => ['class', 'style', 'title', 'id', 'datetime'],
          'a'      => ['href', 'rel', 'name'],
          'li'     => ['id'],
          'sup'    => ['id'],
          'img'    => ['src', 'title', 'alt', 'width', 'height'],
          'object' => ['width', 'height'],
          'param'  => ['name', 'value'],
          'embed'  => ['allowscriptaccess', 'width', 'height', 'src'],
          'iframe' => ['width', 'height', 'src'],
          'td'     => ['colspan', 'rowspan'],
          'th'     => ['colspan', 'rowspan']
        },
        protocols: {
          'a' => { 'href' => ['ftp', 'http', 'https', 'mailto', '#fn', '#fnref', :relative] },
          'img' => {'src'  => ['http', 'https', :relative]},
          'iframe' => {'src'  => ['http', 'https']},
          'embed' => {'src'  => ['http', 'https']},
          'object' => {'src'  => ['http', 'https']},
          'li' => {'id' => ['fn']},
          'sup' => {'id' => ['fnref']}
        },
        transformers: transformers
      }
    end
def sanitize_config
      {
        elements: %w(
          p br a span sub sup strong em div hr abbr s
          ul ol li
          blockquote cite pre code kbd
          h1 h2 h3 h4 h5 h6
          img object param del
          table tr td th thead tbody
          figure figcaption
          mark del ins
        ),
        attributes: {
          :all     => ['class', 'style', 'title', 'id', 'datetime'],
          'a'      => ['href', 'rel', 'name'],
          'li'     => ['id'],
          'sup'    => ['id'],
          'img'    => ['src', 'title', 'alt', 'width', 'height'],
          'object' => ['width', 'height'],
          'param'  => ['name', 'value'],
          'embed'  => ['allowscriptaccess', 'width', 'height', 'src'],
          'iframe' => ['width', 'height', 'src'],
          'td'     => ['colspan', 'rowspan'],
          'th'     => ['colspan', 'rowspan']
        },
        protocols: {
          'a' => { 'href' => ['ftp', 'http', 'https', 'mailto', '#fn', '#fnref', :relative] },
          'img' => {'src'  => ['http', 'https', :relative]},
          'iframe' => {'src'  => ['http', 'https']},
          'embed' => {'src'  => ['http', 'https']},
          'object' => {'src'  => ['http', 'https']},
          'li' => {'id' => ['fn']},
          'sup' => {'id' => ['fnref']}
        },
        transformers: transformers
      }
    end
Return a hash of configuration values for the sanitize gem. Please refer
 to the documentation for sanitize for details:

 https://github.com/rgrove/sanitize#custom-configuration