Issue 4027 - make the download button available for windows insider users

static/js/index.js

 (function()
 {
   var visibleTab;
   var container;
 
   window.toggleMore = function()
   {
     if (container.className == "hidden")
       container.className = visibleTab || getDefaultTab();
     else
@@ skipping 11 matching lines @@
   {
     var content = document.getElementById("content");
     var ua = content.className.match(/ua\-([^\s]+)/);
     visibleTab = ua && ua[1] || "firefox";
     return visibleTab;
   }
 
   function init()
   {
     container = document.getElementById("more-container");
+    if(document.getElementById("content").className.indexOf("edge") > -1)

[Sebastian Noack, 2016/05/17 08:50:13]

Perhaps moving this check inside checkEdgeSupport(). Then you could simply store
the value of document.getElementById("content") in a variable instead
duplication the lookup.

[saroyanm, 2016/05/17 12:38:54]

Done.

+      checkEdgeSupport();
+  }
+
+  function checkEdgeSupport()
+  {
+    if (!window.navigator.userAgent)

[saroyanm, 2016/05/13 10:50:20]

userAgent detection through navigator is deprecated (
https://developer.mozilla.org/en-US/docs/Web/API/NavigatorID/userAgent ), I'm
not sure if there is another way to detect the users, but this way is not
reliable currently and can start not working at anypoint in the future. Maybe
there is a feature that has been added in the new builds or maybe we can check
if the extension support is available on Edge versions, please let me know guys
if you know better way to detect this.

[Sebastian Noack, 2016/05/17 08:50:13]

I don't think there is a different way to detect the browser versions on the
client side. However, I don't expect navigator.userAgent going away any time
soon, and in particular not while we need that check here, since a lot of
websites rely on it. So I think it's fine to rely on navigator.userAgent here.

[saroyanm, 2016/05/17 12:38:53]

Acknowledged.

+      return;
+
+    var match = window.navigator.userAgent.match(/Edge\/(\d+.\d+)/);
+    if (match && match.length > 0 && parseFloat(match[1]) >= 14.14342)

[Sebastian Noack, 2016/05/17 08:50:13]

The check for |match.length > 0| is redundant. If there is a match it will
always be an array with one element per group (even if the group would be
optional).

[saroyanm, 2016/05/17 12:38:54]

Done.

+      document.getElementById("content").className += " edge-supported";

[Sebastian Noack, 2016/05/17 08:50:13]

How about using classList? We don't need to care about compatibility with old IE
versions here.

[saroyanm, 2016/05/17 12:38:53]

Good point

[saroyanm, 2016/05/17 12:38:54]

Done.

   }
 
   init();
 })();