{{- /*
  Link render hook. Opens external links in a new tab, and only external ones.

  A destination is external when it is absolute and points somewhere this site does
  not serve. Both halves of the baseURL are compared, not just the host: on a project
  page such as https://user.github.io/some-theme/, a link to another project on the
  same host is external. Relative destinations, mailto: and tel: are never external,
  and are not parsed at all - urls.Parse errors on some of what Markdown allows.

  The file must not end with a newline. A link renders inline, so a trailing newline
  becomes whitespace between the link and whatever follows it - putting a space before
  the full stop in "see the [docs](/docs/)."
*/ -}}
{{- $dest := .Destination -}}
{{- $external := false -}}
{{- if or (hasPrefix $dest "http://") (hasPrefix $dest "https://") (hasPrefix $dest "//") -}}
  {{- $external = true -}}
  {{- $base := urls.Parse site.BaseURL -}}
  {{- $basePath := strings.TrimSuffix "/" ($base.Path | default "/") -}}
  {{- with urls.Parse $dest -}}
    {{- $path := strings.TrimSuffix "/" (.Path | default "/") -}}
    {{- /* Compared segment by segment, so a site at /theme does not swallow /theme-other. */ -}}
    {{- if and (eq .Host $base.Host) (or (eq $path $basePath) (hasPrefix $path (printf "%s/" $basePath))) -}}
      {{- $external = false -}}
    {{- end -}}
  {{- end -}}
{{- end -}}
<a href="{{ $dest | safeURL }}"{{ with .Title }} title="{{ . }}"{{ end }}{{ if $external }} target="_blank" rel="noopener"{{ end }}>{{ .Text | safeHTML }}</a>