From: Colin Watson <cjwatson@debian.org>
Date: Tue, 1 Oct 2024 13:48:05 +0000 (+0100)
Subject: Support loading comments from Mastodon
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~cjwatson/git?a=commitdiff_plain;h=467b445c3d66c79caa119c846c47f2b5213caccc;p=blog.git

Support loading comments from Mastodon

Lightly adapted from:
https://carlschwan.eu/2020/12/29/adding-comments-to-your-static-blog-with-mastodon/
---

diff --git a/m.css/pelican-theme/templates/article_footer.html b/m.css/pelican-theme/templates/article_footer.html
index 6282168f..6e3330d3 100644
--- a/m.css/pelican-theme/templates/article_footer.html
+++ b/m.css/pelican-theme/templates/article_footer.html
@@ -1 +1,195 @@
+{% if MASTODON_HOST and MASTODON_USERNAME and article.metadata['mastodon-id'] %}
+<section id="comments" class="article-content">
+  <h2>Comments</h2>
+  <p>With an account on the Fediverse or Mastodon, you can respond to this <a href="https://{{ MASTODON_HOST }}/@{{ MASTODON_USERNAME }}/{{ article.metadata['mastodon-id'] }}">post</a>. Since Mastodon is decentralized, you can use your existing account hosted by another Mastodon server or compatible platform if you don't have an account on this one. Known non-private replies are displayed below.</p>
+  <p>Learn how this is implemented <a class="link" href="https://carlschwan.eu/2020/12/29/adding-comments-to-your-static-blog-with-mastodon/">here</a>.</p>
+
+  <p id="mastodon-comments-list"><button id="load-comment">Load comments</button></p>
+  <div id="comments-wrapper">
+    <noscript><p>Loading comments relies on JavaScript. Try enabling JavaScript and reloading, or visit <a href="https://{{ MASTODON_HOST }}/@{{ MASTODON_USERNAME }}/{{ article.metadata['mastodon-id'] }}">the original post</a> on Mastodon.</p></noscript>
+  </div>
+  <noscript>You need JavaScript to view the comments.</noscript>
+  <script src="/assets/js/purify.min.js"></script>
+  <script type="text/javascript">
+    function escapeHtml(unsafe) {
+      return unsafe
+           .replace(/&/g, "&amp;")
+           .replace(/</g, "&lt;")
+           .replace(/>/g, "&gt;")
+           .replace(/"/g, "&quot;")
+           .replace(/'/g, "&#039;");
+    }
+    function emojify(input, emojis) {
+      let output = input;
+
+      emojis.forEach(emoji => {
+        let picture = document.createElement("picture");
+
+        let source = document.createElement("source");
+        source.setAttribute("srcset", escapeHtml(emoji.url));
+        source.setAttribute("media", "(prefers-reduced-motion: no-preference)");
+
+        let img = document.createElement("img");
+        img.className = "emoji";
+        img.setAttribute("src", escapeHtml(emoji.static_url));
+        img.setAttribute("alt", `:${ emoji.shortcode }:`);
+        img.setAttribute("title", `:${ emoji.shortcode }:`);
+        img.setAttribute("width", "20");
+        img.setAttribute("height", "20");
+
+        picture.appendChild(source);
+        picture.appendChild(img);
+
+        output = output.replace(`:${ emoji.shortcode }:`, picture.outerHTML);
+      });
+
+      return output;
+    }
+
+    function loadComments() {
+      let commentsWrapper = document.getElementById("comments-wrapper");
+      let loadCommentsButton = document.getElementById("load-comment");
+      loadCommentsButton.innerHTML = "Loading";
+      fetch('https://{{ MASTODON_HOST }}/api/v1/statuses/{{ article.metadata['mastodon-id'] }}/context')
+        .then(function(response) {
+          return response.json();
+        })
+        .then(function(data) {
+          let descendants = data['descendants'];
+          if(
+            descendants &&
+            Array.isArray(descendants) &&
+            descendants.length > 0
+          ) {
+            commentsWrapper.innerHTML = "";
+
+            descendants.forEach(function(status) {
+                console.log(descendants)
+              if( status.account.display_name.length > 0 ) {
+                status.account.display_name = escapeHtml(status.account.display_name);
+                status.account.display_name = emojify(status.account.display_name, status.account.emojis);
+              } else {
+                status.account.display_name = status.account.username;
+              };
+
+              let instance = "";
+              if( status.account.acct.includes("@") ) {
+                instance = status.account.acct.split("@")[1];
+              } else {
+                instance = "{{ MASTODON_HOST }}";
+              }
+
+              const isReply = status.in_reply_to_id !== "{{ article.metadata['mastodon-id'] }}";
+
+              let op = false;
+              if( status.account.acct == "{{ MASTODON_USERNAME }}" ) {
+                op = true;
+              }
+
+              status.content = emojify(status.content, status.emojis);
+
+              let avatarSource = document.createElement("source");
+              avatarSource.setAttribute("srcset", escapeHtml(status.account.avatar));
+              avatarSource.setAttribute("media", "(prefers-reduced-motion: no-preference)");
+
+              let avatarImg = document.createElement("img");
+              avatarImg.className = "avatar";
+              avatarImg.setAttribute("src", escapeHtml(status.account.avatar_static));
+              avatarImg.setAttribute("alt", `@${ status.account.username }@${ instance } avatar`);
+
+              let avatarPicture = document.createElement("picture");
+              avatarPicture.appendChild(avatarSource);
+              avatarPicture.appendChild(avatarImg);
+
+              let avatar = document.createElement("a");
+              avatar.className = "avatar-link";
+              avatar.setAttribute("href", status.account.url);
+              avatar.setAttribute("rel", "external nofollow");
+              avatar.setAttribute("title", `View profile at @${ status.account.username }@${ instance }`);
+              avatar.appendChild(avatarPicture);
+
+              let instanceBadge = document.createElement("a");
+              instanceBadge.className = "instance";
+              instanceBadge.setAttribute("href", status.account.url);
+              instanceBadge.setAttribute("title", `@${ status.account.username }@${ instance }`);
+              instanceBadge.setAttribute("rel", "external nofollow");
+              instanceBadge.textContent = instance;
+
+              let display = document.createElement("span");
+              display.className = "display";
+              display.setAttribute("itemprop", "author");
+              display.setAttribute("itemtype", "http://schema.org/Person");
+              display.innerHTML = status.account.display_name;
+
+              let header = document.createElement("header");
+              header.className = "author";
+              header.appendChild(display);
+              header.appendChild(instanceBadge);
+
+              let permalink = document.createElement("a");
+              permalink.setAttribute("href", status.url);
+              permalink.setAttribute("itemprop", "url");
+              permalink.setAttribute("title", `View comment at ${ instance }`);
+              permalink.setAttribute("rel", "external nofollow");
+              permalink.textContent = new Date( status.created_at ).toLocaleString('en-US', {
+                dateStyle: "long",
+                timeStyle: "short",
+              });
+
+              let timestamp = document.createElement("time");
+              timestamp.setAttribute("datetime", status.created_at);
+              timestamp.appendChild(permalink);
+
+              let main = document.createElement("main");
+              main.setAttribute("itemprop", "text");
+              main.innerHTML = status.content;
+
+              let interactions = document.createElement("footer");
+              if(status.favourites_count > 0) {
+                let faves = document.createElement("a");
+                faves.className = "faves";
+                faves.setAttribute("href", `${ status.url }/favourites`);
+                faves.setAttribute("title", `Favorites from ${ instance }`);
+                faves.textContent = status.favourites_count;
+
+                interactions.appendChild(faves);
+              }
+
+              let comment = document.createElement("article");
+              comment.id = `comment-${ status.id }`;
+              comment.className = isReply ? "comment comment-reply" : "comment";
+              comment.setAttribute("itemprop", "comment");
+              comment.setAttribute("itemtype", "http://schema.org/Comment");
+              comment.appendChild(avatar);
+              comment.appendChild(header);
+              comment.appendChild(timestamp);
+              comment.appendChild(main);
+              comment.appendChild(interactions);
+
+              if(op === true) {
+                comment.classList.add("op");
+
+                avatar.classList.add("op");
+                avatar.setAttribute(
+                  "title",
+                  "Blog post author; " + avatar.getAttribute("title")
+                );
+
+                instanceBadge.classList.add("op");
+                instanceBadge.setAttribute(
+                  "title",
+                  "Blog post author: " + instanceBadge.getAttribute("title")
+                );
+              }
+
+              commentsWrapper.innerHTML += DOMPurify.sanitize(comment.outerHTML);
+            });
+          }
+          loadCommentsButton.hidden = true;
+        });
+      }
+      document.getElementById("load-comment").addEventListener("click", loadComments);
+  </script>
+</section>
+{% endif %}
 <p>Posted{% if article.authors %} by {% for author in article.authors %}<a href="{{ author.url|format_siteurl|e }}">{{ author|e }}</a>{% endfor %}{% endif %} on <time datetime="{{ article.date.isoformat() }}">{{ article.locale_date }}</time> in <a href="{{ article.category.url|format_siteurl|e }}">{{ article.category|e }}</a>.{% if article.modified %} <span class="m-label m-success">updated <time datetime="{{ article.modified.isoformat() }}">{{ article.locale_modified }}</time></span>{% endif %}{% if article.archived == 'True' %} <span class="m-label m-warning">archived</span>{% endif %}{% if article.status == 'draft' %} <span class="m-label m-dim">draft</span>{% endif %}{% if article.tags %} Tags: {% for tag in article.tags %}<a href="{{ tag.url|format_siteurl|e }}">{{ tag|e }}</a>{% if not loop.last %}, {% endif %}{% endfor %}.{% endif %}</p>
diff --git a/pelicanconf.py b/pelicanconf.py
index d833e04c..1ca72c37 100644
--- a/pelicanconf.py
+++ b/pelicanconf.py
@@ -56,3 +56,6 @@ M_LINKS_FOOTER2 = [
     ('Liberapay', 'https://liberapay.com/cjwatson/donate'),
     ]
 M_SOCIAL_TWITTER_SITE = '@colmmacuait'
+
+MASTODON_HOST = 'mastodon.ie'
+MASTODON_USERNAME = 'cjwatson'