Feature request: default options for generated html tags

[arkadiyt]

Hi,

I'm using kramdown for static site generation and I have lots of links / anchor tags in my outputted html. When a user clicks on one of my external links, the new window's javascript has access to my opening window and can redirect it to a phishing page. The full details for this issue are documented here:
https://mathiasbynens.github.io/rel-noopener/

The fix for this is to generate links like <a href="url" rel="noopener">title</a>, which ensures that window.opener is null in the new window. Right now I'm adding this to all my links manually using kramdown's span IAL: [title](url){:rel="noopener"}. However this gets tedious and error-prone as there are so many links. Would it be possible to get a config option for default attributes on outputted html elements? I imagine this could be useful for other cases as well - applying classes to generated output for styling, etc.

[gettalong]

The standard way to customize this would be to adapt the HTML converter to your needs since this is something very specific.

However, it might be useful if such a functionality would indeed exist for all elements. I'm just not quite sure if this is really the case.

[glebm]

@arkadiyt For now, you can post-process the HTML with e.g. Nokogiri:

html = Nokogiri::HTML.fragment(html).tap do |doc|
  doc.css('a').each do |node|
    node['href'] ||= '#'
    # Add attributes to external links only:
    if node['href'] =~ %r{\A(?:\w+:)?//}
      node['target'] = '_blank'
      node['rel'] = 'nofollow noopener'
    end
  end
end.to_html

[ccorn]

This seems to apply only to links augmented with target="_blank". In my experiments, if I open a non-augmented link in a new tab via context menu, window.opener is null.

In some of my kramdown texts, I have abbreviations in use like the following:

{:n: target="_blank"}

So I just need to append {:n}.

One can do likewise for links to untrusted targets:

{:xn: target="_blank" rel="nofollow noreferrer noopener"}

and then just append {:xn} where applicable.

My point is: This seems to apply only to links that you have already an IAL for, so you just have to change that IAL, not provide new ones.

[arkadiyt]

ccorn:
I didn't realize you could alias the attributes like that, thanks for the tip.

glebm:
The postprocessing approach is what I ended up using - it was simpler to me than figuring out adapting the html converter and making that into a jekyll plugin.

I still think it might be a useful feature but I understand if it gets closed as won't fix

[gettalong]

One thing: If this were implemented, it would have some performance impact on the conversion because there would need to be additional checks for each and every element. However, I don't think that the impact would be great.