Add interactive link previews

public/style.css

@@ -8484,6 +8484,23 @@ span.icon-rss::before {
   height: var(--image-size);
   object-fit: cover;
 }
+.project-header-img {
+  width: 100%;
+  height: var(--height-5);
+  background-color: rgba(255, 255, 255, 0.5);
+  background-size: cover;
+}
+.project-links {
+  background-color: var(--c-transparent-background);
+  display: flex;
+  align-items: center;
+  --link-color: var(--color);
+  font-weight: bold;
+}
+.project-links::after {
+  content: "\200b";
+  padding: var(--spacing-2) 0;
+}
 
 /* src/rawdata/scss/showcase.css */
 .showcase-item .gradient {

src/links/links.go

@@ -0,0 +1,94 @@
+package links
+
+import "regexp"
+
+//
+// This is all in its own package so we can compile it to wasm without building extra junk.
+//
+
+// An online site/service for which we recognize the link
+type Service struct {
+	Name     string
+	IconName string
+	Regex    *regexp.Regexp
+}
+
+var Services = []Service{
+	// {
+	// 	Name:     "itch.io",
+	// 	IconName: "itch",
+	// 	Regex:    regexp.MustCompile(`://(?P<username>[\w-]+)\.itch\.io`),
+	// },
+	{
+		Name:     "App Store",
+		IconName: "app-store",
+		Regex:    regexp.MustCompile(`^https?://apps.apple.com`),
+	},
+	{
+		Name:     "Bluesky",
+		IconName: "bluesky",
+		Regex:    regexp.MustCompile(`^https?://bsky.app/profile/(?P<username>[\w.-]+)$`),
+	},
+	{
+		Name:     "Discord",
+		IconName: "discord",
+		Regex:    regexp.MustCompile(`^https?://discord\.gg`),
+	},
+	{
+		Name:     "GitHub",
+		IconName: "github",
+		Regex:    regexp.MustCompile(`^https?://github\.com/(?P<username>[\w/-]+)`),
+	},
+	{
+		Name:     "GitLab",
+		IconName: "gitlab",
+		Regex:    regexp.MustCompile(`^https?://gitlab\.com/(?P<username>[\w/-]+)`),
+	},
+	{
+		Name:     "Google Play",
+		IconName: "google-play",
+		Regex:    regexp.MustCompile(`^https?://play\.google\.com`),
+	},
+	{
+		Name:     "Patreon",
+		IconName: "patreon",
+		Regex:    regexp.MustCompile(`^https?://patreon\.com/(?P<username>[\w-]+)`),
+	},
+	{
+		Name:     "Twitch",
+		IconName: "twitch",
+		Regex:    regexp.MustCompile(`^https?://twitch\.tv/(?P<username>[\w/-]+)`),
+	},
+	{
+		Name:     "Twitter",
+		IconName: "twitter",
+		Regex:    regexp.MustCompile(`^https?://(twitter|x)\.com/(?P<username>\w+)`),
+	},
+	{
+		Name:     "Vimeo",
+		IconName: "vimeo",
+		Regex:    regexp.MustCompile(`^https?://vimeo\.com/(?P<username>\w+)`),
+	},
+	{
+		Name:     "YouTube",
+		IconName: "youtube",
+		Regex:    regexp.MustCompile(`youtube\.com/(c/)?(?P<username>[@\w/-]+)$`),
+	},
+}
+
+func ParseKnownServicesForUrl(url string) (service Service, username string) {
+	for _, svc := range Services {
+		match := svc.Regex.FindStringSubmatch(url)
+		if match != nil {
+			username := ""
+			if idx := svc.Regex.SubexpIndex("username"); idx >= 0 {
+				username = match[idx]
+			}
+
+			return svc, username
+		}
+	}
+	return Service{
+		IconName: "website",
+	}, ""
+}

src/parsing/wasm/parsingmain.go

@@ -5,16 +5,25 @@ package main
 import (
 	"syscall/js"
 
+	"git.handmade.network/hmn/hmn/src/links"
 	"git.handmade.network/hmn/hmn/src/parsing"
 )
 
 func main() {
-	js.Global().Set("parseMarkdown", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	js.Global().Set("parseMarkdown", js.FuncOf(func(this js.Value, args []js.Value) any {
 		return parsing.ParseMarkdown(args[0].String(), parsing.ForumPreviewMarkdown)
 	}))
-	js.Global().Set("parseMarkdownEdu", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	js.Global().Set("parseMarkdownEdu", js.FuncOf(func(this js.Value, args []js.Value) any {
 		return parsing.ParseMarkdown(args[0].String(), parsing.EducationPreviewMarkdown)
 	}))
+	js.Global().Set("parseKnownServicesForUrl", js.FuncOf(func(this js.Value, args []js.Value) any {
+		service, username := links.ParseKnownServicesForUrl(args[0].String())
+		return js.ValueOf(map[string]any{
+			"service":  service.Name,
+			"icon":     service.IconName,
+			"username": username,
+		})
+	}))
 
 	var done chan struct{}
 	<-done // block forever

src/rawdata/scss/projects.css

@@ -72,3 +72,26 @@
   height: var(--image-size);
   object-fit: cover;
 }
+
+.project-header-img {
+  /* w-100 h5 bg-white-50 bg-center cover */
+  width: 100%;
+  height: var(--height-5);
+  /* TODO(redesign): Better placeholder */
+  background-color: rgba(255, 255, 255, 0.5);
+  background-size: cover;
+}
+
+.project-links {
+  background-color: var(--c-transparent-background);
+  display: flex;
+  align-items: center;
+  --link-color: var(--color);
+  font-weight: bold;
+
+  /* make sure secondary links render at the right height despite SVG size */
+  &::after {
+    content: '\200b';
+    padding: var(--spacing-2) 0;
+  }
+}

src/templates/mapping.go

@@ -4,13 +4,13 @@ import (
 	"fmt"
 	"html/template"
 	"net/netip"
-	"regexp"
 	"strconv"
 	"strings"
 
 	"git.handmade.network/hmn/hmn/src/calendar"
 	"git.handmade.network/hmn/hmn/src/hmndata"
 	"git.handmade.network/hmn/hmn/src/hmnurl"
+	"git.handmade.network/hmn/hmn/src/links"
 	"git.handmade.network/hmn/hmn/src/models"
 )
 
@@ -240,95 +240,8 @@ var UnknownUser = User{
 	AvatarUrl: UserAvatarUrl(nil),
 }
 
-// An online site/service for which we recognize the link
-type LinkService struct {
-	Name     string
-	IconName string
-	Regex    *regexp.Regexp
-}
-
-var LinkServices = []LinkService{
-	// {
-	// 	Name:     "itch.io",
-	// 	IconName: "itch",
-	// 	Regex:    regexp.MustCompile(`://(?P<username>[\w-]+)\.itch\.io`),
-	// },
-	{
-		Name:     "App Store",
-		IconName: "app-store",
-		Regex:    regexp.MustCompile(`^https?://apps.apple.com`),
-	},
-	{
-		Name:     "Bluesky",
-		IconName: "bluesky",
-		Regex:    regexp.MustCompile(`^https?://bsky.app/profile/(?P<username>[\w.-]+)$`),
-	},
-	{
-		Name:     "Discord",
-		IconName: "discord",
-		Regex:    regexp.MustCompile(`^https?://discord\.gg`),
-	},
-	{
-		Name:     "GitHub",
-		IconName: "github",
-		Regex:    regexp.MustCompile(`^https?://github\.com/(?P<username>[\w/-]+)`),
-	},
-	{
-		Name:     "GitLab",
-		IconName: "gitlab",
-		Regex:    regexp.MustCompile(`^https?://gitlab\.com/(?P<username>[\w/-]+)`),
-	},
-	{
-		Name:     "Google Play",
-		IconName: "google-play",
-		Regex:    regexp.MustCompile(`^https?://play\.google\.com`),
-	},
-	{
-		Name:     "Patreon",
-		IconName: "patreon",
-		Regex:    regexp.MustCompile(`^https?://patreon\.com/(?P<username>[\w-]+)`),
-	},
-	{
-		Name:     "Twitch",
-		IconName: "twitch",
-		Regex:    regexp.MustCompile(`^https?://twitch\.tv/(?P<username>[\w/-]+)`),
-	},
-	{
-		Name:     "Twitter",
-		IconName: "twitter",
-		Regex:    regexp.MustCompile(`^https?://(twitter|x)\.com/(?P<username>\w+)`),
-	},
-	{
-		Name:     "Vimeo",
-		IconName: "vimeo",
-		Regex:    regexp.MustCompile(`^https?://vimeo\.com/(?P<username>\w+)`),
-	},
-	{
-		Name:     "YouTube",
-		IconName: "youtube",
-		Regex:    regexp.MustCompile(`youtube\.com/(c/)?(?P<username>[@\w/-]+)$`),
-	},
-}
-
-func ParseKnownServicesForLink(link *models.Link) (service LinkService, username string) {
-	for _, svc := range LinkServices {
-		match := svc.Regex.FindStringSubmatch(link.URL)
-		if match != nil {
-			username := ""
-			if idx := svc.Regex.SubexpIndex("username"); idx >= 0 {
-				username = match[idx]
-			}
-
-			return svc, username
-		}
-	}
-	return LinkService{
-		IconName: "website",
-	}, ""
-}
-
 func LinkToTemplate(link *models.Link) Link {
-	service, username := ParseKnownServicesForLink(link)
+	service, username := links.ParseKnownServicesForUrl(link.URL)
 	return Link{
 		Name:        link.Name,
 		Url:         link.URL,

src/templates/src/include/link_editor.html

@@ -5,14 +5,14 @@
 	</legend>
 	<div class="pa3 input-group">
 		<div id="links" class="flex flex-column g2 relative">
-			<div class="b">Primary Links</div>
+			<div class="b primary_links">Primary Links</div>
 			<div class="b drop_slot secondary_links">Secondary Links</div>
 		</div>
 		<template id="link_row">
 			<div class="link_row drop_slot w-100 flex flex-row items-center" data-tmpl="root">
 				<span class="link_handle svgicon pr3 pointer grab" onmousedown="startLinkDrag(event)">{{ svg "draggable" }}</span>
-				<input data-tmpl="nameInput" class="link_name mr3 w5" type="text" placeholder="Name" />
-				<input data-tmpl="urlInput" class="link_url flex-grow-1" type="url" placeholder="Link" />
+				<input data-tmpl="nameInput" class="link_name mr3 w5" type="text" placeholder="Name" oninput="linkInput(event)" />
+				<input data-tmpl="urlInput" class="link_url flex-grow-1" type="url" placeholder="Link" oninput="linkInput(event)" />
 				<a class="delete_link svgicon link-normal pl3 f3" href="javascript:;" onclick="deleteLink(event)">{{ svg "delete" }}</a>
 			</div>
 		</template>
@@ -51,6 +51,8 @@
 	function addLink(e) {
 		e.preventDefault();
 		linksContainer.appendChild(linkTemplate().root);
+
+		fireLinkEditEvent();
 	}
 
 	function deleteLink(e) {
@@ -59,6 +61,8 @@
 		l.remove();
 
 		ensureLinksEmptyState();
+
+		fireLinkEditEvent();
 	}
 
 	function ensureLinksEmptyState() {
@@ -169,9 +173,19 @@
 
 		document.body.classList.remove("grabbing");
 		draggingLink = null;
+
+		fireLinkEditEvent();
 	}
 	window.addEventListener("mouseup", endLinkDrag);
 	window.addEventListener("mousemove", doLinkDrag);
+
+	function linkInput(e) {
+		fireLinkEditEvent();
+	}
+
+	function fireLinkEditEvent() {
+		window.dispatchEvent(new Event("linkedit"));
+	}
 	</script>
 </fieldset>
 

src/templates/src/project_edit.html

@@ -6,9 +6,20 @@
 	<script src="{{ static "js/templates.js" }}"></script>
 	<script src="{{ static "js/base64.js" }}"></script>
 	<script src="{{ static "js/markdown_upload.js" }}"></script>
+	<script src="{{ static "go_wasm_exec.js" }}"></script>
+
+	<script>
+		const go = new Go();
+		WebAssembly.instantiateStreaming(fetch('{{ static "parsing.wasm" }}'), go.importObject)
+			.then(result => {
+				go.run(result.instance); // don't await this; we want it to be continuously running
+				updateLinkPreviews();
+			});
+		window.parseKnownServicesForUrl = null; // will be set by the Go code
+	</script>
 	
 	<style>
-		#desc-preview:empty::after {
+		#desc_preview:empty::after {
 			content: 'A preview of your description will appear here.';
 			color: var(--dimmer-color);
 			font-style: italic;
@@ -195,7 +206,38 @@
 			</div>
 		</form>
 		<div class="flex-fair bl pa4">
-			<div id="desc-preview" class="w-100 post-content"></div>
+			<!-- Link / card templates -->
+			<template id="primary_link">
+				<!-- need href -->
+				<a data-tmpl="root" class="ph3 pv2 flex items-center"><span data-tmpl="name"></span><span class="svgicon f6 ml2">{{ svg "arrow-right-up" }}</span></a>
+			</template>
+			<template id="secondary_link">
+				<!-- need href and title -->
+				<a data-tmpl="root" class="ph2 flex"><!-- need icon --></a>
+			</template>
+			<div hidden>
+				{{ range .AllLogos }}
+					<span id="link-icon-{{ .Name }}">{{ .Svg }}</span>
+				{{ end }}
+			</div>
+
+			<!--
+				NOTE(ben): This is a copy-paste from project_homepage.html right now.
+				We don't have a good story for sharing templates between Go and JS.
+			-->
+
+			<!-- Header image / links -->
+			<div id="header_img_preview" class="project-header-img"><!-- Needs background-image -->
+				<div class="flex justify-end pa3">
+					<div class="flex g3">
+						<div id="primary_links_preview" class="project-links hide-if-empty"></div>
+						<div id="secondary_links_preview" class="project-links ph1 hide-if-empty"></div>
+					</div>
+				</div>
+			</div>
+
+			<!-- Long description preview -->
+			<div id="desc_preview" class="w-100 post-content"></div>
 		</div>
 	</div>
 	<input type="file" multiple name="file_input" id="file_input" class="dn" />{{/* NOTE(mark): copied NOTE(asaf): Placing this outside the form to avoid submitting it to the server by accident */}}
@@ -235,7 +277,7 @@
 		const projectName = "{{ .Project.Name }}";
 	{{ end }}
 	const description = document.querySelector('#full_description');
-	const descPreview = document.querySelector('#desc-preview');
+	const descPreview = document.querySelector('#desc_preview');
 	const { clear: clearDescription } = autosaveContent({
 		inputEl: description,
 		storageKey: `project-description/${projectName}`,
@@ -397,5 +439,64 @@
 		{{ .TextEditor.UploadUrl }}
 	);
 
+	/////////////////////
+	// Link management //
+	/////////////////////
+
+	const primaryLinkTemplate = makeTemplateCloner("primary_link");
+	const secondaryLinkTemplate = makeTemplateCloner("secondary_link");
+
+	function updateLinkPreviews() {
+		const links = document.querySelector("#links");
+		const linksChildren = Array.from(links.children);
+
+		const secondaryHeader = links.querySelector(".secondary_links");
+		const rows = links.querySelectorAll(".link_row");
+
+		function index(el) {
+			return linksChildren.indexOf(el);
+		}
+
+		const primaryPreview = document.querySelector("#primary_links_preview");
+		const secondaryPreview = document.querySelector("#secondary_links_preview");
+
+		primaryPreview.innerHTML = "";
+		secondaryPreview.innerHTML = "";
+
+		const indexOfSecondary = index(secondaryHeader);
+		for (const row of rows) {
+			const name = row.querySelector(".link_name").value;
+			const url = row.querySelector(".link_url").value;
+
+			const primary = index(row) < indexOfSecondary;
+			if (primary) {
+				const l = primaryLinkTemplate();
+				l.root.href = url;
+				l.name.innerText = name;
+				primaryPreview.appendChild(l.root);
+			} else {
+				let icon = "website";
+				let title = "";
+				if (parseKnownServicesForUrl) {
+					const guess = parseKnownServicesForUrl(url);
+					icon = guess.icon;
+					title = guess.service;
+					if (guess.username) {
+						title += ` (${guess.username})`;
+					}
+				}
+				const iconSVG = document.querySelector(`#link-icon-${icon}`).innerHTML;
+				
+				const l = secondaryLinkTemplate();
+				l.root.href = url;
+				l.root.title = name || title;
+				l.root.innerHTML = iconSVG;
+				secondaryPreview.appendChild(l.root);
+			}
+		}
+	}
+	updateLinkPreviews();
+	window.addEventListener("linkedit", () => updateLinkPreviews());
+
 	</script>
 {{ end }}

src/templates/src/project_homepage.html

@@ -10,8 +10,8 @@
 {{ define "content" }}
 <div class="flex justify-center">
 	<div class="flex-grow-1 flex flex-column items-center mw-site pt4">
-		<div class="w-100 h5 bg-white-50 bg-center cover" style="background-image: url('{{ .Project.HeaderImage }}')">
-			<div class="flex justify-between pa3 link-normal b">
+		<div class="project-header-img" style="background-image: url('{{ .Project.HeaderImage }}')">
+			<div class="flex justify-between pa3">
 				<div class="flex g3">
 					{{ if .CanEdit }}
 						<div class="bg-transparent flex">
@@ -21,18 +21,17 @@
 				</div>
 				<div class="flex g3">
 					{{ with .PrimaryLinks }}
-						<div class="bg-transparent flex">
+						<div class="project-links">
 							{{ range . }}
 								<a class="ph3 pv2 flex items-center" href="{{ .Url }}">{{ .Name }}<span class="svgicon f6 ml2">{{ svg "arrow-right-up" }}</span></a>
 							{{ end }}
 						</div>
 					{{ end }}
 					{{ with .SecondaryLinks }}
-						<div class="bg-transparent flex items-center ph1">
+						<div class="project-links ph1">
 							{{ range . }}
 								<a class="ph2 flex" href="{{ .Url }}" title="{{ .ServiceName }}{{ with .Username }} ({{ . }}){{ end }}">{{ svg (strjoin "logos/" .Icon) }}</a>
 							{{ end }}
-							<div class="pv2">&#8203;</div><!-- make sure secondary links render at the right height despite SVG size -->
 						</div>
 					{{ end }}
 				</div>

src/templates/templates.go

@@ -155,6 +155,23 @@ func GetImg(file string) []byte {
 	return utils.Must1(io.ReadAll(img))
 }
 
+func ListImgsDir(dir string) []fs.DirEntry {
+	var imgs fs.ReadDirFS
+	if config.Config.DevConfig.LiveTemplates {
+		imgs = utils.DirFS("src/templates/img").(fs.ReadDirFS)
+	} else {
+		imgs = Imgs
+		dir = filepath.Join("img/", dir)
+	}
+
+	entries, err := imgs.ReadDir(dir)
+	if err != nil {
+		panic(err)
+	}
+
+	return entries
+}
+
 var controlCharRegex = regexp.MustCompile(`\p{Cc}`)
 
 var HMNTemplateFuncs = template.FuncMap{
@@ -247,10 +264,7 @@ var HMNTemplateFuncs = template.FuncMap{
 		}
 	},
 	"svg": func(name string) template.HTML {
-		contents, err := Imgs.ReadFile(fmt.Sprintf("img/%s.svg", name))
-		if err != nil {
-			panic("SVG not found: " + name)
-		}
+		contents := GetImg(fmt.Sprintf("%s.svg", name))
 		return template.HTML(contents)
 	},
 	"static": func(filepath string) string {

src/templates/types.go

@@ -228,6 +228,11 @@ type Link struct {
 	Primary     bool   `json:"primary"`
 }
 
+type Icon struct {
+	Name string        `json:"name"`
+	Svg  template.HTML `json:"svg"`
+}
+
 type Podcast struct {
 	Title       string
 	Description string

src/website/projects.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"html/template"
 	"image"
 	"io"
 	"net/http"
@@ -372,6 +373,8 @@ type ProjectEditData struct {
 	APICheckUsernameUrl                string
 	LogoMaxFileSize, HeaderMaxFileSize int
 
+	AllLogos []templates.Icon
+
 	TextEditor templates.TextEditor
 }
 
@@ -396,7 +399,7 @@ func ProjectNew(c *RequestContext) ResponseData {
 		currentJam = hmndata.CurrentJam()
 		if currentJam != nil {
 			project.JamParticipation = []templates.ProjectJamParticipation{
-				templates.ProjectJamParticipation{
+				{
 					JamName:       currentJam.Name,
 					JamSlug:       currentJam.Slug,
 					Participating: true,
@@ -416,6 +419,8 @@ func ProjectNew(c *RequestContext) ResponseData {
 		LogoMaxFileSize:     ProjectLogoMaxFileSize,
 		HeaderMaxFileSize:   ProjectHeaderMaxFileSize,
 
+		AllLogos: allLogos(),
+
 		TextEditor: templates.TextEditor{
 			MaxFileSize: AssetMaxSize(c.CurrentUser),
 			UploadUrl:   c.UrlContext.BuildAssetUpload(),
@@ -558,6 +563,8 @@ func ProjectEdit(c *RequestContext) ResponseData {
 		LogoMaxFileSize:     ProjectLogoMaxFileSize,
 		HeaderMaxFileSize:   ProjectHeaderMaxFileSize,
 
+		AllLogos: allLogos(),
+
 		TextEditor: templates.TextEditor{
 			MaxFileSize: AssetMaxSize(c.CurrentUser),
 			UploadUrl:   c.UrlContext.BuildAssetUpload(),
@@ -1102,3 +1109,16 @@ func CanEditProject(user *models.User, owners []*models.User) bool {
 	}
 	return false
 }
+
+func allLogos() []templates.Icon {
+	var logos []templates.Icon
+	logoEntries := templates.ListImgsDir("logos")
+	for _, logo := range logoEntries {
+		logos = append(logos, templates.Icon{
+			Name: logo.Name()[:len(logo.Name())-len(".svg")],
+			Svg:  template.HTML(templates.GetImg(fmt.Sprintf("logos/%s", logo.Name()))),
+		})
+	}
+
+	return logos
+}