Issue 6786 - Switch Safari 12+ users to content blocking API

safari/ext/content.js

Index: safari/ext/content.js
diff --git a/safari/ext/content.js b/safari/ext/content.js
index 25d64b006a20a69e14c8e2f9db5d4686ca8970d8..13992e1f5e4a46574aed4c4c967e9df25fd5fd04 100644
--- a/safari/ext/content.js
+++ b/safari/ext/content.js
@@ -25,23 +25,33 @@
 
   /* Intialization */
 
-  var beforeLoadEvent = document.createEvent("Event");
-  beforeLoadEvent.initEvent("beforeload", false, true);
+  var applicatonVersion = navigator.userAgent.match(/Version\/([\d.]+)/)[1];
+  var majorApplicationVersion = parseInt(applicatonVersion.split(".")[0], 10);
 
-  // Decide if we should use the new content blocker API or not. (Note when the
-  // API is used Safari breaks the canLoad function, making it either throw an
-  // exception or return true when used.)
+  var beforeLoadEvent;
   var usingContentBlockerAPI = true;
-  try
-  {
-    if (safari.self.tab.canLoad(beforeLoadEvent,
-                                {category: "request",
-                                 payload: {type: "prefs.get",
-                                           key: "safariContentBlocker"}}) != true)
-      usingContentBlockerAPI = false;
-  }
-  catch (e)
+
+  // Safari 12 automatically disables extensions which use the old canLoad API,
+  // so avoid using the old APIs on Safari 12!
+  if (majorApplicationVersion < 12)
   {
+    beforeLoadEvent = document.createEvent("Event");
+    beforeLoadEvent.initEvent("beforeload", false, true);
+
+    // Decide if we should use the new content blocker API or not. (Note when the
+    // API is used Safari breaks the canLoad function, making it either throw an
+    // exception or return true when used.)
+    try

[Sebastian Noack, 2018/07/13 18:27:53]

It seems this kind of feature detection is obsolete now. Instead, we can only
rely on the Safari version now. In fact, there doesn't seem to be any scenario
where this would fail (on Safari 6-11).

[kzar, 2018/07/13 18:58:33]

I don't think this logic is redundant, it's how we figure out if the content
blocking is being used or not, which is still relevant for Safari < 12.

+    {
+      if (safari.self.tab.canLoad(beforeLoadEvent,
+                                  {category: "request",
+                                   payload: {type: "prefs.get",
+                                             key: "safariContentBlocker"}}) != true)
+        usingContentBlockerAPI = false;
+    }
+    catch (e)
+    {
+    }
   }
 
   var isTopLevel;
@@ -63,7 +73,8 @@
       isTopLevel: isTopLevel,
       isPrerendered: isPrerendered,
       documentId: documentId,
-      legacyAPISupported: "canLoad" in safari.self.tab &&
+      legacyAPISupported: majorApplicationVersion < 12 &&
+                          "canLoad" in safari.self.tab &&
                           "onbeforeload" in Element.prototype
     });
   }
@@ -183,14 +194,17 @@
     },
     sendMessageSync: function(message)
     {
-      return safari.self.tab.canLoad(
-        beforeLoadEvent,
-        {
-          category: "request",
-          documentId: documentId,
-          payload: message
-        }
-      );
+      if (majorApplicationVersion < 12)
+      {
+        return safari.self.tab.canLoad(
+          beforeLoadEvent,
+          {
+            category: "request",
+            documentId: documentId,
+            payload: message
+          }
+        );
+      }
     }
   };