From 8e3b6e4992afd1f17cd69a32c402ebb3288c521a Mon Sep 17 00:00:00 2001
From: Geoff Rich <geoff.rich@alaskaair.com>
Date: Fri, 13 Nov 2020 16:38:33 -0800
Subject: [PATCH] docs: remove some h4s from the table of contents

---
 site/content/docs/01-component-format.md | 10 ++--
 site/src/routes/docs/_sections.js        | 12 +++--
 site/src/utils/attributes.js             | 61 ++++++++++++++++++++++++
 3 files changed, 75 insertions(+), 8 deletions(-)
 create mode 100644 site/src/utils/attributes.js

diff --git a/site/content/docs/01-component-format.md b/site/content/docs/01-component-format.md
index 7286205bdf..7c5f423ca8 100644
--- a/site/content/docs/01-component-format.md
+++ b/site/content/docs/01-component-format.md
@@ -24,7 +24,7 @@ All three sections — script, styles and markup — are optional.
 
 A `<script>` block contains JavaScript that runs when a component instance is created. Variables declared (or imported) at the top level are 'visible' from the component's markup. There are four additional rules:
 
-#### 1. `export` creates a component prop
+#### 1. `export` creates a component prop { data-toc-ignore }
 
 ---
 
@@ -85,7 +85,7 @@ You can use reserved words as prop names.
 </script>
 ```
 
-#### 2. Assignments are 'reactive'
+#### 2. Assignments are 'reactive' { data-toc-ignore }
 
 ---
 
@@ -107,7 +107,7 @@ Because Svelte's reactivity is based on assignments, using array methods like `.
 </script>
 ```
 
-#### 3. `$:` marks a statement as reactive
+#### 3. `$:` marks a statement as reactive { data-toc-ignore }
 
 ---
 
@@ -143,7 +143,7 @@ If a statement consists entirely of an assignment to an undeclared variable, Sve
 </script>
 ```
 
-#### 4. Prefix stores with `$` to access their values
+#### 4. Prefix stores with `$` to access their values { data-toc-ignore }
 
 ---
 
@@ -172,7 +172,7 @@ Local variables (that do not represent store values) must *not* have a `$` prefi
 </script>
 ```
 
-#### Store contract
+#### Store contract { data-toc-ignore }
 
 ```js
 store = { subscribe: (subscription: (value: any) => void) => (() => void), set?: (value: any) => void }
diff --git a/site/src/routes/docs/_sections.js b/site/src/routes/docs/_sections.js
index 3657ba85ac..b730abbe2f 100644
--- a/site/src/routes/docs/_sections.js
+++ b/site/src/routes/docs/_sections.js
@@ -3,6 +3,7 @@ import path from 'path';
 import { SLUG_PRESERVE_UNICODE, SLUG_SEPARATOR } from '../../../config';
 import { extract_frontmatter, extract_metadata, link_renderer } from '@sveltejs/site-kit/utils/markdown.js';
 import { make_session_slug_processor } from '@sveltejs/site-kit/utils/slug';
+import { extract_attributes } from '../../utils/attributes';
 import { highlight } from '../../utils/highlight';
 import marked from 'marked';
 
@@ -85,6 +86,10 @@ export default function() {
 			renderer.heading = (text, level, rawtext) => {
 				let slug;
 
+				let extracted = extract_attributes(text, rawtext);
+				text = extracted.text;
+				rawtext = extracted.raw;
+
 				const match = /<a href="([^"]+)"[^>]*>(.+)<\/a>/.exec(text);
 				if (match) {
 					slug = match[1];
@@ -93,7 +98,8 @@ export default function() {
 					slug = make_slug(rawtext);
 				}
 
-				if (level === 3 || level === 4) {
+				const tocIgnore = 'data-toc-ignore' in extracted.attrs;
+				if ((level === 3 || level === 4) && !tocIgnore) {
 					const title = text
 						.replace(/<\/?code>/g, '')
 						.replace(/\.(\w+)(\((.+)?\))?/, (m, $1, $2, $3) => {
@@ -106,8 +112,8 @@ export default function() {
 				}
 
 				return `
-					<h${level}>
-						<span id="${slug}" class="offset-anchor" ${level > 4 ? 'data-scrollignore' : ''}></span>
+					<h${level} ${extracted.attrstring}>
+						<span id="${slug}" class="offset-anchor" ${level > 4 || tocIgnore ? 'data-scrollignore' : ''}></span>
 						<a href="docs#${slug}" class="anchor" aria-hidden="true"></a>
 						${text}
 					</h${level}>`;
diff --git a/site/src/utils/attributes.js b/site/src/utils/attributes.js
new file mode 100644
index 0000000000..1a823cab11
--- /dev/null
+++ b/site/src/utils/attributes.js
@@ -0,0 +1,61 @@
+const ATTRS_REGEX = /^(.+)\s+\{(.+)\}$/;
+/**
+ * Extracts attributes from markdown text to be applied to the resulting HTML.
+ * @example
+ * // returns { 
+ * //   text: 'Heading',
+ * //   raw: '<code>Heading</code>',
+ * //   attrs: { id: 'important', class: 'red', test: 'true' },
+ * //   attrstring: 'id="important" class="red" test="true"'
+ * // }
+ * extract_attributes(
+ *   'Heading { #important .red test=true }', 
+ *   '<code>Heading</code> { #important .red test=true }'
+ * );
+ * ```
+ * @param {string} text 
+ * @param {string} raw 
+ */
+export function extract_attributes(text, raw) {
+	try {
+		const textMatch = text.match(ATTRS_REGEX);
+		const rawMatch = raw && raw.match(ATTRS_REGEX);
+		const attrs = textMatch ? parse_attributes(textMatch[2]) : {};
+
+		return {
+			text: textMatch ? textMatch[1] : text,
+			raw: rawMatch ? rawMatch[1] : raw,
+			attrs,
+			attrstring: Object.keys(attrs).map(key => `${key}="${attrs[key].trim()}"`).join(' ')
+		}
+	} catch (err) {
+		console.log(err);
+		return {
+			text,
+			raw,
+			attrs: {},
+			attrstring: ''
+		};
+	}
+}
+
+function parse_attributes(raw_attributes) {
+	const attributes = raw_attributes.split(' ');
+	const result = { };
+	attributes.forEach(attr => {
+		if (!attr) return;
+		if (attr.startsWith('#')) {
+			result.id = attr.substring(1);
+		} else if (attr.startsWith('.')) {
+			if (!result.class) {
+				result.class = '';
+			}
+			result.class += attr.substring(1) + ' ';
+		} else {
+			let [key, value = ''] = attr.split('=');
+			result[key] = value;
+		}
+	})
+
+	return result;
+}
\ No newline at end of file