FEATURE: Show Reply count on blog index page when embedding

app/controllers/embed_controller.rb

@@ -24,6 +24,20 @@ class EmbedController < ApplicationController
     discourse_expires_in 1.minute
   end
 
+  def count
+
+    topic_embeds = TopicEmbed.where(embed_url: params[:embed_url]).includes(:topic).all
+
+    by_url = {}
+    topic_embeds.each do |te|
+      by_url["#{te.embed_url}#discourse-comments"] = I18n.t('embed.replies', count: te.topic.posts_count - 1)
+    end
+
+    respond_to do |format|
+      format.js { render json: {counts: by_url}, callback: params[:callback] }
+    end
+  end
+
   private
 
     def ensure_embeddable

config/routes.rb

@@ -243,6 +243,7 @@ Discourse::Application.routes.draw do
   get "topics/private-messages-unread/:username" => "list#private_messages_unread", as: "topics_private_messages_unread", constraints: {username: USERNAME_ROUTE_FORMAT}
 
   get 'embed/comments' => 'embed#comments'
+  get 'embed/count' => 'embed#count'
 
   # Topic routes
   get "t/:slug/:topic_id/wordpress" => "topics#wordpress", constraints: {topic_id: /\d+/}

public/javascripts/count.js

@@ -0,0 +1,45 @@
+/* global discourseUrl:true */
+
+(function() {
+
+
+  // Discover the URLs we want counts for
+  var links = document.getElementsByTagName("a"),
+      countFor = [];
+
+  for(var i=0; i<links.length; i++) {
+    var href = links[i].href;
+    if (href && href.length) {
+      var m = /^(.*)#discourse-comments$/.exec(href);
+      if (m && m[1]) { countFor.push(m[1]); }
+    }
+  }
+  //
+  // JSONP callback to update counts
+  window.discourseUpdateCounts = function(result) {
+    if (result && result.counts) {
+      var byUrl = result.counts;
+      for (var i=0; i<links.length; i++) {
+        var link = links[i],
+            linkCount = byUrl[link];
+
+        if (linkCount) {
+          var t = document.createTextNode(" (" + linkCount + ")");
+          link.appendChild(t);
+        }
+      }
+    }
+  };
+
+  if (countFor.length > 0) {
+    // Send JSONP request for the counts
+    var d = document.createElement('script');
+    d.src = discourseUrl + "embed/count?callback=discourseUpdateCounts&";
+
+    for (var j=0; j<countFor.length; j++) {
+      d.src += "&" + "embed_url[]=" + encodeURIComponent(countFor[j]);
+    }
+    (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(d);
+  }
+
+})();