Showdown: Automatic anchor links

[buremba]

Is there any way to add anchor links with showdown similar to Github READMEs?

[tivie]

Not out of the box. But it's quite possible with an extension (check fiddle https://jsfiddle.net/tivie/knf9nb8f/)

// Extension
showdown.extension('header-anchors', function() {

    var ancTpl = '$1<a id="user-content-$3" class="anchor" href="#$3" aria-hidden="true"><svg aria-hidden="true" class="octicon octicon-link" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>$4';

  return [{
    type: 'html',
    regex: /(<h([1-3]) id="([^"]+?)">)(.*<\/h\2>)/g,
    replace: ancTpl
  }];
});

[buremba]

@tivie thanks a lot!

[kirkins]

Is this for anchor links that have a space?
I'm finding that all my single word anchors work automatically but not anchors with two or more words.

[jiasli]

A prettier css with unnecessary space removed. Borrowed from GitHub css.

.anchor
{
    float: left;
    line-height: 1;
    margin-left: -20px;
    padding-right: 4px
}

h1 .anchor:focus,
h2 .anchor:focus,
h3 .anchor:focus
{
  outline: none
}

h1 .octicon-link,
h2 .octicon-link,
h3 .octicon-link
{
  color: #1b1f23;
  vertical-align: middle;
  visibility: hidden
}

h1:hover .anchor .octicon-link,
h2:hover .anchor .octicon-link,
h3:hover .anchor .octicon-link
{
  visibility: visible
}