/*!
 * HashChange.js
 * @version 1.0
 * @author mach3
 * @example
 * var foo = new HashChange();
 * foo.config({ onInit:myInitFunc, onChange:myChangeFunc, interval:100 });
 * foo.start(); // When start to observe.
 * foo.stop(); // When stop to observe.
 */
 
/**
 * Creates a new HashChange.
 * @constructor
 * @class observe changes of locatin.hash.
 * @param {Object} options Configuration options.
 */
var HashChange = function( options ){
 
	var my, vars, methods ;
 
	my = this;
	vars = {
		onChange : null,
		onInit : null,
		interval : 100,
		timer : null,
		hash : null
	};
	methods = {
		isFunction : function( target ){
			return typeof( target ) === "function" ;
		}
	};
 
	/**
	 * Configure options.
	 * @param {Object} options Configuration options.
	 */
	my.config = function( options ){
		for( i in options ){
			if( !vars.hasOwnProperty( i ) ){ continue; }
			vars[i] = options[i];
		}
	};
	/**
	 * Start to observe.
	 */
	my.start = function(){
		my.run();
	};
	/**
	 * Check whether location.hash has been changed or not,
	 * call onInit/onChange function if set,
	 * and call itself by timeout again.
	 */
	my.run = function(){
		var h = location.hash;
		if( vars.hash === null && methods.isFunction( vars.onInit ) ){
			vars.onInit( h );
		} else if ( vars.hash !== h && methods.isFunction( vars.onChange ) ){
			vars.onChange( h );
		}
		vars.hash = location.hash;
		vars.timer = setTimeout( my.run, vars.interval );
	};
	/**
	 * Stop to observe.
	 */
	my.stop = function(){
		clearTimeout( vars.timer );
	};
 
	my.config( options );
};

var myHashChange = new HashChange();
myHashChange.config({
	onInit : function( hash ){
		console.log( "Initialize : " + hash );
	},
	onChange : function( hash ){
		console.log( "Change : " + hash );
	}
});
myHashChange.start();