The 404 RedirectOMatic 3000

404.js

$(function(){
  // Fade the page, hide the 'Not found' message a little, there's still hope!
  $('#title, #page').css('opacity', 0.3);

  // If the JSON is taking its time or fail then reset
  var timeout = setTimeout(function(){
    $('#page, #title').css('opacity', 1);
  }, 2000);

  // Get the JSON. Using jQuery.
  $.getJSON('/js/url_migrations.json?r='+Math.random(), function(data){
    var found = false, tracking = '?utm_source=404&utm_medium=redirect&utm_campaign=pagenotfoundredirect';
    // I am curious to see the effectiveness of this hence the Analytics flags

    $.each(data['redirects'], function(idx, url){
      if(url[0] == window.location.pathname || window.location.hash == '#test'){
        window.location.replace(url[1] + tracking); found = true; return false;
        // Epic win! Lets redirect to the new page
      }
    });

    // So if we have no match and the URL looks Tumblrish then redirect to Tumblr
    if(!found && window.location.pathname.match(/^\/post\/[0-9]+/)) {
      found = true;
      window.location.replace('http://tumblog.alexeckermann.com' + window.location.pathname + tracking);
    }
    
    // Cleanup...
    if(found) return;
    $('#page, #title').css('opacity', 1);
    clearTimeout(timeout);
  });
  
});

url_migrations.json

{
  "redirects":
    [
      [ "/post/2711036222/quick-tip-going-completely-xib-less",
        "/tutorials/going-completely-xib-less.html", false ],
        "/tutorials/filtering-nsarray-with-nspredicate.html", false ],
      [ "/post/957671497/first-steps-with-core-data",
        "/tutorials/first-steps-with-core-data.html", false ],
      [ "/post/957196387/fine-art-of-uitableviews",
        "/tutorials/fine-art-of-uitableview.html", false ],
      [ "...old Tumblr URL...",
        "... new Jekyll URL...", 'a flag if its external, not implemented' ]
    ]
}