Jetpack page-mod/bfcache

page-mod-bfcache.js

/*
 * testing page-mod's persistence with bfcache
 */
 
require('sdk/page-mod').PageMod({
  include: '*',
  contentScript: 'new ' + fn
});  

// Content script
function fn () {
  var count = 0;
  console.log("load: " + document.location.href);
  setInterval(function () {
    ++count;
    console.log("ping " + count + ": " + document.location.href);
  }, 3000);
}

/*
Output: Loading `products` page, then clicking on `about`, 
going "back" to `products` and then "forward" to `about`,
persisting counts and pings without reloading

info: pagemod: load: http://www.mozilla.org/en-US/products/
info: pagemod: ping 1: http://www.mozilla.org/en-US/products/
info: pagemod: ping 2: http://www.mozilla.org/en-US/products/
info: pagemod: ping 3: http://www.mozilla.org/en-US/products/
info: pagemod: load: http://www.mozilla.org/en-US/about/
info: pagemod: ping 1: http://www.mozilla.org/en-US/about/
info: pagemod: ping 2: http://www.mozilla.org/en-US/about/
info: pagemod: ping 3: http://www.mozilla.org/en-US/about/
info: pagemod: ping 4: http://www.mozilla.org/en-US/products/
info: pagemod: ping 5: http://www.mozilla.org/en-US/products/
info: pagemod: ping 6: http://www.mozilla.org/en-US/products/
info: pagemod: ping 4: http://www.mozilla.org/en-US/about/
info: pagemod: ping 5: http://www.mozilla.org/en-US/about/
info: pagemod: ping 6: http://www.mozilla.org/en-US/about/

*/