A few education improvements

src/config/config.go.example

@@ -1,3 +1,5 @@
+//go:build !js
+
 package config
 
 import (

src/config/jsconfig.go

@@ -0,0 +1,7 @@
+//go:build js
+
+package config
+
+var Config = HMNConfig{
+	BaseUrl: "https://handmade.network",
+}

src/parsing/parsing.go

@@ -14,6 +14,7 @@ import (
 
 // Used for rendering real-time previews of post content.
 var ForumPreviewMarkdown = makeGoldmark(
+	false,
 	goldmark.WithExtensions(makeGoldmarkExtensions(MarkdownOptions{
 		Previews: true,
 		Embeds:   true,
@@ -22,6 +23,7 @@ var ForumPreviewMarkdown = makeGoldmark(
 
 // Used for generating the final HTML for a post.
 var ForumRealMarkdown = makeGoldmark(
+	false,
 	goldmark.WithExtensions(makeGoldmarkExtensions(MarkdownOptions{
 		Previews: false,
 		Embeds:   true,
@@ -30,6 +32,7 @@ var ForumRealMarkdown = makeGoldmark(
 
 // Used for generating plain-text previews of posts.
 var PlaintextMarkdown = makeGoldmark(
+	false,
 	goldmark.WithExtensions(makeGoldmarkExtensions(MarkdownOptions{
 		Previews: false,
 		Embeds:   true,
@@ -39,6 +42,7 @@ var PlaintextMarkdown = makeGoldmark(
 
 // Used for processing Discord messages
 var DiscordMarkdown = makeGoldmark(
+	false,
 	goldmark.WithExtensions(makeGoldmarkExtensions(MarkdownOptions{
 		Previews: false,
 		Embeds:   false,
@@ -48,20 +52,24 @@ var DiscordMarkdown = makeGoldmark(
 
 // Used for rendering real-time previews of post content.
 var EducationPreviewMarkdown = makeGoldmark(
+	true,
 	goldmark.WithExtensions(makeGoldmarkExtensions(MarkdownOptions{
 		Previews:  true,
 		Embeds:    true,
 		Education: true,
 	})...),
+	goldmark.WithRendererOptions(html.WithUnsafe()),
 )
 
 // Used for generating the final HTML for a post.
 var EducationRealMarkdown = makeGoldmark(
+	true,
 	goldmark.WithExtensions(makeGoldmarkExtensions(MarkdownOptions{
 		Previews:  false,
 		Embeds:    true,
 		Education: true,
 	})...),
+	goldmark.WithRendererOptions(html.WithUnsafe()),
 )
 
 func ParseMarkdown(source string, md goldmark.Markdown) string {
@@ -79,8 +87,9 @@ type MarkdownOptions struct {
 	Education bool
 }
 
-func makeGoldmark(opts ...goldmark.Option) goldmark.Markdown {
+func makeGoldmark(rawHTML bool, opts ...goldmark.Option) goldmark.Markdown {
 	// We need to re-create Goldmark's default parsers to disable HTML parsing.
+	// Or enable it again. yay
 
 	// See parser.DefaultBlockParsers
 	blockParsers := []util.PrioritizedValue{
@@ -105,6 +114,11 @@ func makeGoldmark(opts ...goldmark.Option) goldmark.Markdown {
 		util.Prioritized(parser.NewEmphasisParser(), 500),
 	}
 
+	if rawHTML {
+		blockParsers = append(blockParsers, util.Prioritized(parser.NewHTMLBlockParser(), 900))
+		inlineParsers = append(inlineParsers, util.Prioritized(parser.NewRawHTMLParser(), 400))
+	}
+
 	opts = append(opts, goldmark.WithParser(parser.NewParser(
 		parser.WithBlockParsers(blockParsers...),
 		parser.WithInlineParsers(inlineParsers...),

src/parsing/wasm/parsingmain.go

@@ -16,6 +16,6 @@ func main() {
 		return parsing.ParseMarkdown(args[0].String(), parsing.EducationPreviewMarkdown)
 	}))
 
-	var done chan bool
+	var done chan struct{}
 	<-done // block forever
 }

src/templates/src/education_article.html

@@ -5,6 +5,38 @@
         .hide-notes .note {
             display: none;
         }
+
+        .toc {
+            position: relative;
+            overflow: hidden;
+            transition: all 40ms ease-in-out;
+        }
+
+        .toc::after {
+            content: '';
+            position: absolute;
+            left: 0;
+            top: 0;
+            width: 100%;
+            height: 100%;
+            border-left: 0 solid var(--link-color);
+            transition: all 40ms ease-in-out;
+        }
+
+        .toc.active {
+            background-color: var(--dim-background);
+        }
+
+        .toc.active::after {
+            border-left-width: 0.25rem;
+        }
+
+        .toc-1 {}
+        .toc-2 { margin-left: 1rem; }
+        .toc-3 { margin-left: 2rem; }
+        .toc-4 { margin-left: 3rem; }
+        .toc-5 { margin-left: 4rem; }
+        .toc-6 { margin-left: 5rem; }
     </style>
 {{ end }}
 
@@ -22,12 +54,50 @@
         <div class="edu-article flex-grow-1 post-content">
             {{ .Article.Content }}
         </div>
-        <div class="ml3 flex-shrink-0 w5">
+        <div class="sidebar ml3 flex-shrink-0 w-30">
-            I'm a sidebar!
+            <div class="toc-container flex flex-column">
+                {{ range .TOC }}
+                    <a href="#{{ .ID }}" class="db ph2 pv1 br2 toc toc-{{ .Level }}">{{ .Text }}</a>
+                {{ end }}
+            </div>
         </div>
     </div>
 
     <script>
+        const sidebar = document.querySelector('.sidebar');
+        const tocContainer = document.querySelector('.toc-container');
+        const tocEntries = Array.from(document.querySelectorAll('.toc')).map(tocLink => ({
+            link: tocLink,
+            heading: document.querySelector(tocLink.getAttribute('href')),
+        }));
+
+        // TOC
+        const FUDGE = 100;
+        const TOC_TOP_SPACING = 20;
+        document.addEventListener('scroll', () => {
+            // Stickiness
+            const stick = window.pageYOffset > sidebar.offsetTop-TOC_TOP_SPACING;
+            tocContainer.style.position = stick ? 'fixed' : 'static';
+            tocContainer.style.top = `${TOC_TOP_SPACING}px`;
+
+            // Active items
+            let activeEntry = null;
+            for (const toc of tocEntries) {
+                if (window.pageYOffset >= toc.heading.offsetTop-FUDGE) {
+                    activeEntry = toc;
+                } else {
+                    break;
+                }
+            }
+            for (const toc of tocEntries) {
+                toc.link.classList.remove('active');
+            }
+            if (activeEntry) {
+                activeEntry.link.classList.add('active');
+            }
+        });
+
+        // Notes
         function toggleNotes() {
             document.querySelector('.edu-article').classList.toggle('hide-notes',
                 document.querySelector('#hide-notes').checked,

src/website/education.go

@@ -8,6 +8,8 @@ import (
 	"net/http"
 	"net/url"
 	"regexp"
+	"strconv"
+	"strings"
 	"time"
 
 	"git.handmade.network/hmn/hmn/src/db"
@@ -66,6 +68,7 @@ func EducationArticle(c *RequestContext) ResponseData {
 	type articleData struct {
 		templates.BaseData
 		Article   templates.EduArticle
+		TOC       []TOCEntry
 		EditUrl   string
 		DeleteUrl string
 	}
@@ -96,6 +99,11 @@ func EducationArticle(c *RequestContext) ResponseData {
 		tmpl.Article.Content = template.HTML(reEduEditorsNote.ReplaceAllLiteralString(string(tmpl.Article.Content), ""))
 	}
 
+	// Generate TOC and stuff I dunno
+	html, tocEntries := generateTOC(string(tmpl.Article.Content))
+	tmpl.Article.Content = template.HTML(html)
+	tmpl.TOC = tocEntries
+
 	var res ResponseData
 	res.MustWriteTemplate("education_article.html", tmpl, c.Perf)
 	return res
@@ -426,3 +434,31 @@ func eduArticleURL(a *models.EduArticle) string {
 		panic("unknown education article type")
 	}
 }
+
+var reHeading = regexp.MustCompile(`<h([1-6])>(.*?)</h[1-6]>`)
+var reNotSimple = regexp.MustCompile(`[^a-zA-Z0-9-_]+`)
+
+type TOCEntry struct {
+	Text  string
+	ID    string
+	Level int
+}
+
+func generateTOC(html string) (string, []TOCEntry) {
+	var entries []TOCEntry
+	replacinated := reHeading.ReplaceAllStringFunc(html, func(s string) string {
+		m := reHeading.FindStringSubmatch(s)
+		level := m[1]
+		content := m[2]
+		id := strings.ToLower(reNotSimple.ReplaceAllLiteralString(content, "-"))
+
+		entries = append(entries, TOCEntry{
+			Text:  content,
+			ID:    id,
+			Level: utils.Must1(strconv.Atoi(level)),
+		})
+
+		return fmt.Sprintf(`<h%s id="%s">%s</h%s>`, level, id, content, level)
+	})
+	return replacinated, entries
+}