Issue 6786 - Display the Safari App Extension migration page

background.js

Index: background.js
diff --git a/background.js b/background.js
index f76a61f18f02e5c90a0c60cb756ac4a607ccbd54..49d1a4658a11e4e4a3c322d07e91e339fc1dfc7e 100644
--- a/background.js
+++ b/background.js
@@ -62,3 +62,24 @@ port.on("forward", function(msg, sender)
     targetPage.sendMessage(msg.payload);
   }
 });
+
+// Display a page to explain to users of Safari 10 and higher that they need
+// to migrate to our Safari App extension, but only once the migration page
+// is online.
+
+function showMigrationPageWhenReady()
+{
+  fetch("https://eyeo.to/adblockplus/safari-app-extension-migration")

[Sebastian Noack, 2018/07/13 18:01:35]

I wonder, should we perhaps just send a HEAD request instead of downloading the
whole document?

[kzar, 2018/07/13 18:44:04]

Done.

+    .then(function(response)
+    {
+      if (response.ok)
+        ext.showPage(response.url);
+    });
+}
+
+if (Services.vc.compare(require("info").applicationVersion, "10") >= 0)
+{
+  // Show now, and then once every 24 hours.
+  showMigrationPageWhenReady();
+  window.setInterval(showMigrationPageWhenReady, 1000 * 60 * 60 * 24);

[Sebastian Noack, 2018/07/13 18:01:35]

As far as I understand the issue description, we only want to try again in 24h
if the page wasn't online yet. Also then we don't have to bother about the
scenario in which the tab is already open, just using ext.pages.open() here, and
don't need to touch (and re-test) the logic showing the options page.

Furthermore, we might want to call setTimeout() (recursively) instead of using
setInterval(). That is because if an interval is missed while your computer was
in standby/sleep it is skipped, however if a timeout was missed, it is performed
as soon as you resume from standby.

[kzar, 2018/07/13 18:44:04]

I've adjusted the issue description to clarify.
Good point, done.

+}