Parsing Backlinks in Hugo

tips & tricks
1

I’d love to get feedback on performance improvements in the backlinks.html partial I share here:

3 Likes
2

Cool little partial you have here.

As far as performance, you’re only iterating site.RegularPages once, so that seems fine.

I’m no regex expert – though, I hear you are, ha – but the regex seems like the next place I would look. Ways to make it match earlier or on less, etc.

3

Assuming we limit the scope to links in markdown, here is one idea:

  • In a render hook, find the page (site.GetPage) and add the current page to a Scratch “backlinks map” in the target page.
  • In a dummy output format that is rendered first, do a {{ range site.RegularPages }}{{ $tmp := .Content }}{{ end }}
  • Then you should have a ready-to-use backlink index in your Page.Scratch (or Page.Store depending on your requirements) when you render your HTML (or RSS).
4

Unfortunately, 99% of my cross-linking is using relref: It’s easy and does the broken link detection automatically. So the link render hooks won’t work here, right?

5

I’m no expert either. I came up with that regex to remove all the false matches for backlinks. I’ll keep looking for better ways to write that regex.

6

Thinking a bit more… I think I can do this in 2 places:

  • In a link render hook to handle normal md links, and
  • a custom relref shortcode that overrides the default one, and does this Scatch update in the Page’s context.

But I didn’t understand this step:

What does this step do? Also how do we control which output format is rendered first?

7

It’s a way to trigger the render hooks. There is a weight attribute on the output format and I suspect they fall back to the name, so if you prefix it with “_”, e.g. "_preprocessformat` you should be safe.

1 Like
8

Note that when I can get the partialCached thing to run once only you could get a simpler setup by having a function you could include at the top of your template which did the loop above.

1 Like
9

@kaushalmodi I’m a huge fan of obsidian and I’m building a large site where I definitely want to add this feature. But for some reasons, it isn’t working. I spent hours trying to figure it out but without success :-/

I use canonifyURLs = true and disabled relativeURL…could that be the cause?

10

So I have a leaf bundle directory similar to this

content/
├─ Folder/
├─ Category 1/
│  ├─ _index.md
│  ├─ post1.md
│  ├─ post2.md
├─ Category 2/
│  ├─ Subcategory/
│  │  ├─ _index.md
│  │  ├─ post1.md
│  ├─ _index.md

Now, I have over 1500 pages on the website. I want ALL my content check (including lists, _index.md, etc.)

When I setup the partial at the bottom of single.html and list.html

{{ $backlinks := slice }}
{{ $path_base := .page.File.BaseFileName }}
{{ $path_base_re := printf `["/(]%s["/)]` $path_base }}

{{ range where site.RegularPages "RelPermalink" "ne" .page.RelPermalink }}
    {{ if (findRE $path_base_re .RawContent 1) }}
        {{ $backlinks = $backlinks | append . }}
    {{ end }}
{{ end }}

{{ with $backlinks }}
    <section class="backlinks">
        {{ printf "%s" ($.heading | default "<h2>Backlinks</h2>") | safeHTML }}
        <nav>
            <ul>
                {{ range . }}
                    <li><a href="{{ .RelPermalink }}">{{ .Title }}</a></li>
                {{ end }}
            </ul>
        </nav>
    </section>

{{ end }}

Yet nothing comes out.

11

@kaushalmodi Your code is throwing a few errors. It needs to be updated.

execute of template failed at <$.heading>: can’t evaluate field heading in type page.Page

execute of template failed at <.page.File.ContentBaseName>: can’t evaluate field page in type page.Page