From 7af16471cd8a119a04ccd14249b34ce2d7a7eaf2 Mon Sep 17 00:00:00 2001
From: Riley Davis <riley.davis@gmail.com>
Date: Wed, 22 Mar 2017 15:37:27 -0600
Subject: [PATCH] if the asset_url is not present, attempt to find the
 canonical link tag. if not, warn the user and strip the query params.

---
 client/coral-embed/src/index.js | 11 ++++++++++-
 views/article.ejs               |  2 +-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/client/coral-embed/src/index.js b/client/coral-embed/src/index.js
index 21b159e8c..8ebd403b8 100644
--- a/client/coral-embed/src/index.js
+++ b/client/coral-embed/src/index.js
@@ -167,7 +167,16 @@ Talk.render = function (el, opts) {
     el.id = `_${Math.random()}`;
   }
 
-  let asset_url = opts.asset_url || window.location.href.split('#')[0];
+  let asset_url = opts.asset_url;
+  if (!asset_url) {
+    try {
+      asset_url = document.querySelector('link[rel="canonical"]').href;
+    } catch (e) {
+      console.warn('This page does not include a canonical link tag. Talk has inferred this asset_url from the window object. Query params have been stripped, which may cause a single thread to be present across multiple pages.');
+      asset_url = window.location.origin + window.location.pathname;
+    }
+  }
+
   let comment = window.location.hash.slice(1);
 
   let query = {
diff --git a/views/article.ejs b/views/article.ejs
index 3869262ff..5f90cdf4d 100644
--- a/views/article.ejs
+++ b/views/article.ejs
@@ -27,7 +27,7 @@
     <script src="/embed.js" async onload="
       Coral.Talk.render(document.getElementById('coralStreamEmbed'), {
         talk: '/',
-        asset: '<%= asset_url ? asset_url : '' %>'
+        asset_url: '<%= asset_url ? asset_url : '' %>'
       })
     "></script>
   </main>