FlowControl.js

function FlowControl(auto){
	this.auto = !!auto
	this.finish = {}
	this.wait = []
	this.units = {}
	
	if(document.readyState === "complete"){
		this.set("load")
	}else{
		window.addEventListener("load", function(){
			this.set("load")
		}, false)
	}
}

FlowControl.prototype.add = function(name, action, opts){
	var unit = {
		name: name,
		action: action,
		after: (opts && opts.after) || [],
		args: (opts && opts.args) || [],
		bind: (opts && opts.bind) || null,
	}
	if(typeof unit.action !== "function"){
		throw new Error("Action is not function.")
	}
	if(! (unit.after instanceof Array)){
		unit.after = [unit.after]
	}
	if(! (unit.args instanceof Array)){
		unit.args = [unit.args]
	}
	
	if(unit.name !== null){
		if(unit.name in this.units){
			throw new Error("name [[" + unit.name + "]] already exists.")
		}
		
		this.units[unit.name] = unit
	}
	this.wait.push(unit)
	
	if(this.auto){
		this._run()
	}
}

FlowControl.prototype.add_cb = function(name, action, opts){
	var that = this
	return function(/*arguments*/){
		opts.args = [].slice.call(arguments)
		that.add(name, action, opts)
	}
}

FlowControl.prototype.set = function(name){
	if(name in this.units){
		throw new Error("name [[" + unit.name + "]] already exists.")
	}
	this.finish[name] = {name: name}
	this.units[name] = {name: name}
	if(this.auto){
		this._run()
	}
}

FlowControl.prototype._run = function(){
	var before_length, after_length
	var that = this
	do{
		before_length = that.wait.length
		
		that.wait = that.wait.filter(function(e,i,a){
			if(e.after.filter(function(ee){
				return !(ee in that.finish)
			}).length === 0){
				e.action.apply(e.bind, e.args)
				if(e.name !== null)
					that.finish[e.name] = e
				return false
			}
			return true
		})
		
		after_length = that.wait.length
	}while(before_length !== after_length)
}
FlowControl.prototype.run = function(auto){
	this._run()
	if(auto!=null){
		this.auto = !!auto
	}
}
FlowControl.prototype.stop = function(){
	this.auto = false
}

usage.js

/////////////sample///////////////

var fc = new FlowControl
fc.add("b", function(){console.log("b")}, {after:["t","g"]})
fc.run()
console.log("runしてもbはまだ出力されない")
fc.add("g", function(){console.log("g")})
console.log("gは待機するものないけどautoじゃないときはrunするまで実行されない")
fc.add("t", function(){console.log("t")})
fc.run()
console.log("****************")

//
var fc = new FlowControl(true)
fc.add("b", function(){console.log("b")}, {after:["t","g"]})
fc.run()
console.log("runしてもbはまだ出力されない")
fc.add("g", function(){console.log("g")})
console.log("autoなのでgが出力される")
fc.add("t", function(){console.log("t")})
console.log("****************")

//
var obj = {xx:1,yy:2}
var fc = new FlowControl(true)
fc.add("a", function(a,b,c){console.log("a | args =>",a,b,c)}, {args:[1,2,3], after:"b"})
fc.add("b", function(){console.log("b | this =>", this)}, {bind:obj, after:"c"})
setTimeout(fc.add_cb("c", function(a,b){console.log("c | args =>",a,b)}, {after:"d"}), 1000, "zzz1", "zzz2")
fc.add("d", function(){console.log("d | ")})
fc.add(null, function(){console.log("Action that name is null can be registered any number of times.")})
fc.add(null, function(){console.log("Action that name is null can be registered any number of times.")})