This also speeds up situations where you only need the fragments/toc and not the rendered content, e.g. Related
with fragments type indexing:
```bash
name old time/op new time/op delta
RelatedSite-10 12.3ms ± 2% 10.7ms ± 1% -12.95% (p=0.029 n=4+4)
name old alloc/op new alloc/op delta
RelatedSite-10 38.6MB ± 0% 38.2MB ± 0% -1.08% (p=0.029 n=4+4)
name old allocs/op new allocs/op delta
RelatedSite-10 117k ± 0% 115k ± 0% -1.36% (p=0.029 n=4+4)
```
Fixes#10750
The main topic of this commit is that you can now index fragments (content heading identifiers) when calling `.Related`.
You can do this by:
* Configure one or more indices with type `fragments`
* The name of those index configurations maps to an (optional) front matter slice with fragment references. This allows you to link
page<->fragment and page<->page.
* This also will index all the fragments (heading identifiers) of the pages.
It's also possible to use type `fragments` indices in shortcode, e.g.:
```
{{ $related := site.RegularPages.Related .Page }}
```
But, and this is important, you need to include the shortcode using the `{{<` delimiter. Not doing so will create infinite loops and timeouts.
This commit also:
* Adds two new methods to Page: Fragments (can also be used to build ToC) and HeadingsFiltered (this is only used in Related Content with
index type `fragments` and `enableFilter` set to true.
* Consolidates all `.Related*` methods into one, which takes either a `Page` or an options map as its only argument.
* Add `context.Context` to all of the content related Page API. Turns out it wasn't strictly needed for this particular feature, but it will
soon become usefil, e.g. in #9339.
Closes#10711
Updates #9339
Updates #10725
* Removes any surrounding paragraph nodes
* And transfers any attributes from the surrounding paragraph down to the image node
* Adds IsBlock and Ordinal (zero based) field to the image context passed to the image render hooks
IsBlock is set to true if `wrapStandAloneImageWithinParagraph = false` and the image's parent node has only one child.
Closes#8362Fixes#10492Fixes#10494Fixes#10501
Note that we will now fail if `inlineImports` is enabled and we cannot resolve an import.
You can work around this by either:
* Use url imports or imports with media queries.
* Set `skipInlineImportsNotFound=true` in the options
Also get the argument order in the different NewFileError* funcs in line.
Fixes#9895
* Redo the server error template
* Always add the content file context if relevant
* Remove some now superflous error string matching
* Move the server error template to _server/error.html
* Add file context (with position) to codeblock render blocks
* Improve JS build errors
Fixes#9892Fixes#9891Fixes#9893
This commit prevents the most commons case of infinite recursion in link render hooks when the `linkify` option is enabled (see below). This is always a user error, but getting a `stack overflow` (the current stack limit in Go is 1 GB on 64-bit, 250 MB on 32-bit) error isn't very helpful. This fix will not prevent all such errors, though, but we may do better once #9570 is in place.
So, these will fail:
```
<a href="{{ .Destination | safeURL }}" >{{ .Text | markdownify }}</a>
<a href="{{ .Destination | safeURL }}" >{{ .Text | .Page.RenderString }}</a>
```
`.Text` is already rendered to `HTML`. The above needs to be rewritten to:
```
<a href="{{ .Destination | safeURL }}" >{{ .Text | safeHTML }}</a>
<a href="{{ .Destination | safeURL }}" >{{ .Text | safeHTML }}</a>
```
Fixes#8959
For the Position in code blocks we try to match the .Inner with the original source. This isn't always possible.
This commits avoids panics in these situations.
Fixes#9627
You can now create custom hook templates for code blocks, either one for all (`render-codeblock.html`) or for a given code language (e.g. `render-codeblock-go.html`).
We also used this new hook to add support for diagrams in Hugo:
* Goat (Go ASCII Tool) is built-in and enabled by default; just create a fenced code block with the language `goat` and start draw your Ascii diagrams.
* Another popular alternative for diagrams in Markdown, Mermaid (supported by GitHub), can also be implemented with a simple template. See the Hugo documentation for more information.
Updates #7765Closes#9538Fixes#9553Fixes#8520Fixes#6702Fixes#9558
Currently the generated `<pre>` element isn't fully accessible as it can't be focused by keyboard users.
To make this fully accessible, the attribute `tabindex="0"` should be added to the `<pre>` tag.
Closes#7194
