Insert anchor as full heading (#1916)

* Add insert_anchor = "heading"

* Update CHANGELOG.md

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>

CHANGELOG.md

@@ -4,11 +4,11 @@
 
 ### Breaking
 
-- Switch to pulldown-cmark anchor rather than ours, some (very niche) edge cases are not supported anymore, you can
+- Switch to pulldown-cmark anchor system rather than ours, some (very niche) edge cases are not supported anymore, you can
 also specify classes on headers now
 - Now outputs empty taxonomies instead of ignoring them
 - Unify all pages sorting variable names in templates to `lower`/`higher` in order to make it easy to re-use templates and it
-was becoming hard to come up with names
+was becoming hard to come up with names to be honest
 
 ### Other
 - Fix markup for fenced code with linenos
@@ -24,11 +24,12 @@ any pages related to that taxonomy
 - Ignore sections with `render=false` when looking for path collisions
 - Add support for backlinks
 - Add a warning mode for internal/external link checking in case you don't want zola to stop the build on invalid links
-- Always follow symlinks
+- Always follow symlinks when loading the site/assets
 - Add `rel="alternate"` to Atom post links
 - Fix taxonomy `current_path`
 - Fix feed location for taxonomies not in the default language
 - Add `title_bytes` sorting method
+- Add `insert_anchor = "heading"`, which allows users to use the entire heading as a link (rather than needing a seperate icon)
 
 ## 0.15.3 (2022-01-23)
 

components/markdown/src/markdown.rs

@@ -30,6 +30,10 @@ static EMOJI_REPLACER: Lazy<EmojiReplacer> = Lazy::new(EmojiReplacer::new);
 /// [uri-schemes]: https://www.iana.org/assignments/uri-schemes/uri-schemes.xhtml
 static STARTS_WITH_SCHEMA_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"^[0-9A-Za-z\-]+:").unwrap());
 
+/// Matches a <a>..</a> tag, getting the opening tag in a capture group.
+/// Used only with AnchorInsert::Heading to grab it from the template
+static A_HTML_TAG: Lazy<Regex> = Lazy::new(|| Regex::new(r"(<\s*a[^>]*>).*?<\s*/\s*a>").unwrap());
+
 /// Efficiently insert multiple element in their specified index.
 /// The elements should sorted in ascending order by their index.
 ///
@@ -516,7 +520,8 @@ pub fn markdown_to_html(
                 let anchor_idx = match context.insert_anchor {
                     InsertAnchor::Left => start_idx + 1,
                     InsertAnchor::Right => end_idx,
-                    InsertAnchor::None => 0, // Not important
+                    InsertAnchor::Heading => 0,  // modified later to the correct value
+                    InsertAnchor::None => unreachable!(),
                 };
                 let mut c = tera::Context::new();
                 c.insert("id", &id);
@@ -530,7 +535,15 @@ pub fn markdown_to_html(
                     &None,
                 )
                 .context("Failed to render anchor link template")?;
-                anchors_to_insert.push((anchor_idx, Event::Html(anchor_link.into())));
+                if context.insert_anchor != InsertAnchor::Heading {
+                    anchors_to_insert.push((anchor_idx, Event::Html(anchor_link.into())));
+                } else {
+                    if let Some(captures) = A_HTML_TAG.captures(&anchor_link) {
+                        let opening_tag = captures.get(1).map_or("", |m| m.as_str()).to_string();
+                        anchors_to_insert.push((start_idx + 1, Event::Html(opening_tag.into())));
+                        anchors_to_insert.push((end_idx, Event::Html("</a>".into())));
+                    }
+                }
             }
 
             // record heading to make table of contents

components/markdown/tests/markdown.rs

@@ -101,6 +101,9 @@ fn can_insert_anchors() {
     let body =
         common::render_with_insert_anchor(&cases.join("\n"), InsertAnchor::Right).unwrap().body;
     insta::assert_snapshot!(body);
+    let body =
+        common::render_with_insert_anchor(&cases.join("\n"), InsertAnchor::Heading).unwrap().body;
+    insta::assert_snapshot!(body);
 }
 
 #[test]

components/markdown/tests/snapshots/markdown__can_insert_anchors-3.snap

@@ -0,0 +1,10 @@
+---
+source: components/markdown/tests/markdown.rs
+expression: body
+---
+<h1 id="hello"><a class="zola-anchor" href="#hello" aria-label="Anchor link for: hello">Hello</a></h1>
+<h1 id="world"><a class="zola-anchor" href="#world" aria-label="Anchor link for: world">World</a></h1>
+<h1 id="hello-1"><a class="zola-anchor" href="#hello-1" aria-label="Anchor link for: hello-1">Hello!</a></h1>
+<h2 id="rust"><a class="zola-anchor" href="#rust" aria-label="Anchor link for: rust"><a href="https://rust-lang.org">Rust</a></a></h2>
+<h1 id="hello-2"><a class="zola-anchor" href="#hello-2" aria-label="Anchor link for: hello-2">Hello*_()</a></h1>
+

components/utils/src/types.rs

@@ -5,5 +5,12 @@ use serde::{Deserialize, Serialize};
 pub enum InsertAnchor {
     Left,
     Right,
+    Heading,
     None,
 }
+
+impl InsertAnchor {
+    pub fn uses_template(&self) -> bool {
+        matches!(self, InsertAnchor::Left | InsertAnchor::Right)
+    }
+}

docs/content/documentation/content/linking.md

@@ -32,7 +32,7 @@ links working.
 
 ## Anchor insertion
 It is possible to have Zola automatically insert anchor links next to the heading, as you can see on this documentation
-if you hover a title.
+if you hover a title or covering the full heading text.
 
 This option is set at the section level: the `insert_anchor_links` variable on the
 [section front matter page](@/documentation/content/section.md#front-matter).
@@ -47,6 +47,9 @@ The anchor link template has the following variables:
 - `lang`: the current language, unless called from the `markdown` template filter, in which case it will always be `en`
 - `level`: the heading level (between 1 and 6)
 
+If you use `insert_anchor = "heading"`, the template will still be used but only the opening `<a>` tag will get extracted
+from it, everything else will not be used.
+
 ## Internal links
 Linking to other pages and their headings is so common that Zola adds a
 special syntax to Markdown links to handle them: start the link with `@/` and point to the `.md` file you want

docs/content/documentation/content/section.md

@@ -79,7 +79,8 @@ paginate_reversed = false
 # This determines whether to insert a link for each header like the ones you can see on this site if you hover over
 # a header.
 # The default template can be overridden by creating an `anchor-link.html` file in the `templates` directory.
-# This value can be "left", "right" or "none".
+# This value can be "left", "right", "heading" or "none".
+# "heading" means the full heading becomes the text of the anchor.
 insert_anchor_links = "none"
 
 # If set to "true", the section pages will be in the search index. This is only used if