I had an interesting bug combining InstantClick with Clicky.com (a GA stats tracking alternative).

Clicky dynamically adds a JS file to the header so it's asynchronous. It does the same every few minutes to poll and indicate someone's still on the page.

When used with InstantClick, the first tracking request worked fine. But when I clicked - the first AND second Clicky tracking request were sent. Another click meant 3 new requests were sent.

It puzzled me for a minute, before I realized. Clicky's JS didn't have InstantClicks' data-no-instant attribute, so all previous tracking scripts were being re-loaded with every click.

The fix is to push the tracking requests to Clicky manually via InstantClick's on change callback. Then I used JQuery to add the data-no-instant attr to all the clicky script tags in the head:

  InstantClick.on('change', function() {
    clicky.log(location.pathname+location.search, document.title, 'pageview');
    // now stop any clicky scripts from being re-requested each time the page is insta-reloaded, to stop wasted tracking requests
    jQuery("head script[src*='clicky.com']:not([data-no-instant])").attr('data-no-instant', true);
  });

The same might happen with Google Analytics if you're using it asynchronously, but I've not tried that.

Hope this helps someone if they see the same weirdness.

Any one test this with any ad networks running? Clearly you don't want non-visible ads being called.

Interesting to see the differences between InstaClick and Pjax.

InstantClick

  - InstantClick is a little easier to implement, with nothing required server-side
  - InstantClick works to reduce latency by prefetching page content on hover.
  - InstantClick always replaces the body's outerHTML
  - InstantClick provides a YouTube style loading progress bar

Pjax[1]

  - You specify specifically which page element is replaced (using the ID)
  - You set up your app to return only the required page fragment on ajax calls
  - No loading bar is included, but can easily be added
  - Content is not prefetched on hover

I think I still prefer the pjax approach because it sends less data over the wire. However, would be interesting to see a hybrid of the two approaches.

Also worth noting that both essentially turn your site into a single-page app that updates the browser URL bar using pushState. Both approaches also degrade nicely.

[1] https://github.com/defunkt/jquery-pjax

InstantClick seems to be using pjax? at http://instantclick.io/:

    InstantClick uses pushState and Ajax (a combo known as pjax), replacing only the body and the title in the head.

If someone hovers over a link but doesn't click it, will the page load still be accounted as a page view (e.g. by Google Analytics)?

not sure of the details of how prefetch work, but I doubt it( GA requires its little JS snippet to run)

No.

If you guys are interested in testing this out on a "real" site... i just implemented InstantClick on http://www.topiama.com/.

If I spot anything weird I'll let you guys know.

Cool idea.

Not sure how it works now but shouldn't Apple/Google just disable that delay if your viewport is already set to device-width? It's not like you're going to double-tap to zoom in any further.

You're thinking of fastclick. This is different, it's page prefetching so that you start loading the page before the UI event that would normally start loading it happens.

Yes they should, Chrome 34 on Android already does it actually.

When Youtube started to do this "custom progressbar", now my Chrome history is inconsistent, when I type something and open the related history item, a completely different web-page comes. Please, if you are intending to do this, do it correct, don't break the expected behaviour of a browser.

wouldn't it be nice if this was built into the browsers themselves ? probably with a settings to change the timeout etc/or disable the feature ..

Unfortunately, links might change state. Links on some sites will delete records, and a browser has no way of knowing which.

Also, it generates a much larger server load. Look up FasterFox and the related controversy.

Is this something like FastClick[1]?

1. https://github.com/ftlabs/fastclick

FastClick removes the 300/450 ms delay and makes your click trigger right after touchend, InstantClick makes use of this delay (plus the delay between touchstart and touchend) to preload the page.

I don't know, maybe click on the link and see what this is about? Spoiler: no.

>FastClick: eliminating the 300ms delay between a physical tap and the firing of a click event on mobile browsers

>InstantClick: preloading links you are likely to click on