[skip] When not browser focused on a view that refreshes, don’t refresh

[lukebooth]

This would halt the ticker when you’re not currently looking at a view that does polling. Regaining focus calls the given callback and restarts the view.

If you don't think this is a good idea or needs improvement, just comment on this. Thanks

[boblail]

Luke, do you think this'll mess up the dashboards? — like if one of those error messages shows up that we can't click on — or if they never have keyboard focus, they'll just not work?

What do you think of this?

Here's how the Alerts Dashboard uses the Refresher:

new Refresher()
  // ...
  .callback(function() {
    $.get('/alerts/dashboard' + window.location.search, {limit: limit}).done(renderAlerts);
  }).render();

What if the Refresher supported an option where: if callback returned a Promise, it would do something like this:

1. The refresher completes its circle
2. If @waitingForPromise is true, then it stops the refresher
3. Otherwise, it calls callback and checks the return value
4. If callback's return value is a promise, it sets @waitingForPromise = true, calls done on the promise, and, when done is invoked, sets @waitingForPromise = false and, if necessary, resumes the refresher

Clients of Refresher would opt-in to this behavior by returning a promise.

We would then modify the Alerts Dashboard to opt-in to this feature like so:

  new Refresher()
    // ...
    .callback(function() {
-     $.get('/alerts/dashboard' + window.location.search, {limit: limit}).done(renderAlerts);
+     return $.get('/alerts/dashboard' + window.location.search, {limit: limit}).done(renderAlerts);
    }).render();