sequence.js

/**
 * Permanently bind a function to an object.
 *
 * @param fn (function)
 *    Function to bind.
 * @param object (object)
 *    Object scope to force the function to run within.
 * @return
 *    New function, where the argument function is forced to
 *    execute within the scope of object.
 */
function bind(fn, object){
    return function(){
        return fn.apply(object, arguments);
    };
}

/**
 * Chain one function to another so that the second is called 
 * after the first one finishes and is given the result of the
 * first.
 * 
 * @param fn1 (function)
 *    First function to call, it's result will be passed on to 
 *    fn2.
 * @param fn2 (function)
 *    Function to call with the results of the first function.
 * @param waitTime (optional integer)
 *    Time to wait between when the first function finishes and 
 *    when to start the second.
 * @return
 *    New function which, when called with the arguments you'd 
 *    want to call fn1 with, will initiate the chain.
 */
function chain(fn1, fn2){
    var waitTime = arguments.length > 2 ? arguments[2] : 10;
    return function(){
        var returnObj = fn1.apply(null, arguments);
        var obj2 = obj2;
        setTimeout(function(){
            fn2.call(null, returnObj);
        }, waitTime);
        return returnObj;
    };
}

/**
 * Chain together a bunch of functions which will call 
 * eachother and pass along their return values.
 *
 * @param scope (object or null)
 *    The scope within which to call all of the functions.
 * @param fns (Array of Functions)
 *    The functions to make a non-blocking sequence out of.
 * @param waitTime (optional integer)
 *    The amount of time to wait between each function.
 * @return 
 *    A new function which consists of the sequence of functions.  
 *    Call it with the arguments you'd want to pass to the first 
 *    function in the sequence.
 */
function makeSequence(scope, fns){
    var waitTime = arguments.length > 2 ? arguments[2] : 10;
    for(var i = 0, len=fns.length; i < len; i++){
        fns[i] = bind(fns[i],scope);
    }
    for(var len=fns.length, i=len-1; i >= 1; i--){
        fns[i-1] = chain(fns[i-1], fns[i], waitTime);
    }
    return fns[0];
}


/***************************************************************
 *  Example Situation.
 **************************************************************/

function addOne(){
    console.log("addOne()->1+"+this.value);
    this.value++;
    return;
}
var obj = {
    name:"Chained object scope", 
    value: 1
};

var start = makeSequence(obj, [addOne, addOne, addOne, addOne], 200);
start(); // start execution

console.dir(obj);
setTimeout(function(){
    console.dir(obj);
}, 1000);