# Advanced usage
## Frontmatter
By default, frontmatter is copied over "as-is".
Some static site generators are picky about frontmatter and require it to be present.
Some get tripped up when Markdown files don't have frontmatter but start with a list item or horizontal rule.
In these cases, `--frontmatter=always` can be used to insert an empty frontmatter entry.
To completely remove any frontmatter from exported notes, use `--frontmatter=never`.
## Ignoring files
The following files are not exported by default:
* hidden files (can be adjusted with `--hidden`)
* files matching a pattern listed in `.export-ignore` (can be adjusted with `--ignore-file`)
* any files that are ignored by git (can be adjusted with `--no-git`)
* using `--skip-tags foo --skip-tags bar` will skip any files that have the tags `foo` or `bar` in their frontmatter
* using `--only-tags foo --only-tags bar` will skip any files that **don't** have the tags `foo` or `bar` in their frontmatter
(See `--help` for more information).
Notes linking to ignored notes will be unlinked (they'll only include the link text).
Embeds of ignored notes will be skipped entirely.
### Ignorefile syntax
The syntax for `.export-ignore` files is identical to that of [gitignore] files.
Here's an example:
```
# Ignore the directory private that is located at the top of the export tree
/private
# Ignore any file or directory called `test`
test
# Ignore any PDF file
*.pdf
# ..but include special.pdf
!special.pdf
```
For more comprehensive documentation and examples, see the [gitignore] manpage.
## Recursive embeds
It's possible to end up with "recursive embeds" when two notes embed each other.
This happens for example when a `Note A.md` contains `![[Note B]]` but `Note B.md` also contains `![[Note A]]`.
By default, this will trigger an error and display the chain of notes which caused the recursion.
This behavior may be changed by specifying `--no-recursive-embeds`.
Using this mode, if a note is encountered for a second time while processing the original note, instead of embedding it again a link to the note is inserted instead to break the cycle.
## Relative links with Hugo
The [Hugo] static site generator [does not support relative links to files][hugo-relative-linking].
Instead, it expects you to link to other pages using the [`ref` and `relref` shortcodes].
As a result of this, notes that have been exported from Obsidian using obsidian-export do not work out of the box because Hugo doesn't resolve these links correctly.
[Markdown Render Hooks] (only supported using the default `goldmark` renderer) allow you to work around this issue however, making exported notes work with Hugo after a bit of one-time setup work.
Create the file `layouts/_default/_markup/render-link.html` with the following contents:
```
{{- $url := urls.Parse .Destination -}}
{{- $scheme := $url.Scheme -}}
<a href="
{{- if eq $scheme "" -}}
{{- if strings.HasSuffix $url.Path ".md" -}}
{{- relref .Page .Destination | safeURL -}}
{{- else -}}
{{- .Destination | safeURL -}}
{{- end -}}
{{- else -}}
{{- .Destination | safeURL -}}
{{- end -}}"
</a>
{{- /* whitespace stripped here to avoid trailing newline in rendered result caused by file EOL */ -}}
```
And `layouts/_default/_markup/render-image.html` for images:
```
{{- $url := urls.Parse .Destination -}}
{{- $scheme := $url.Scheme -}}
<img src="
{{- if eq $scheme "" -}}
{{- if strings.HasSuffix $url.Path ".md" -}}
{{- relref .Page .Destination | safeURL -}}
{{- else -}}
{{- printf "/%s%s" .Page.File.Dir .Destination | safeURL -}}
{{- end -}}
{{- else -}}
{{- .Destination | safeURL -}}
{{- end -}}"
{{- end -}}
/>
{{- /* whitespace stripped here to avoid trailing newline in rendered result caused by file EOL */ -}}
```
With these hooks in place, links to both notes as well as file attachments should now work correctly.
> Note: If you're using a theme which comes with it's own render hooks, you might need to do a little extra work, or customize the snippets above, to avoid conflicts with the hooks from your theme.
[`ref` and `relref` shortcodes]: https://gohugo.io/content-management/cross-references/
[gitignore]: https://git-scm.com/docs/gitignore
[hugo-relative-linking]: https://notes.nick.groenen.me/notes/relative-linking-in-hugo/
[hugo]: https://gohugo.io
[markdown render hooks]: https://gohugo.io/getting-started/configuration-markup#markdown-render-hooks