A technique for keeping the UI thread moving when you need to do a fair bit of processing

example.js

var loadChain = new LoadChain();

loadChain.push(function(){
  console.log("Intensive work is happening here...");
});

loadChain.push(function(){
  console.log("And some more is happening here...");
});

loadChain.push(function(){
  console.log("And if you have some code to indicate your progess, it'll work!");
});

loadChain.start();

loadchain.js

// A quick and dirty implementation of a queue to prevent the UI thread from being tied up for several seconds, and
// (for example) allow a progress bar to work. You can push functions onto the queue, and when you call myQueue.start(), 
// it will run each function in a chain of window.setTimeout calls.

function LoadChain() {
  this.queue = [];

  this.push = function(f) {
    var self = this;

    // Push a function onto the queue that executes the user-specified function, then sets a timeout to execute the
    // next function if there is one
    this.queue.push(function() {
      f();
      var next = self.queue.shift();
      if(next) window.setTimeout(next, 0);
    });
  };

  this.start = function() {
    var first = this.queue.shift();
    first();
  };
}