Split Nav

splitnav.js

var splitNav = (function() {
	var that = {};
	that.container = null;
	that.lean = 'left';
	that.min = 10;
	that.sumArr = function(arr) {
		z = 0;
		for(var i in arr) {
			z += arr[i];
		}
		return z;
	}
	that.setup = function() {
		$('li.top', that.container).each(function() {
			var weights = [];
			var li = $(this);
			var dad = li.children('ul');
			//Gets the weights of each subnav
			dad.children('li').each(function() {
				var w = 2;
				w += $(this).children('ul').children('li').length;
				weights.push(w);
			});
			//Wrap subnav in a div for further control
			//Change the classname to whatever
			dad.wrap('<div class="sub" />');
			var sum = that.sumArr(weights);
			var half = Math.ceil(sum/2);
			//If threshold is met, split
			if(sum >= that.min) {
				var check = true;
				var index = -1;
				var total = 0;
				for(var i in weights) {
					total += weights[i];
					if(check === true && total >= half) {
						if(that.lean == 'left') {
							//The left column is taller
							index = parseInt(i)+1;	
						} else {
							//The right column is taller
							index = parseInt(i);
						}
						check = false;
					}
				}
				if(index != -1) {
					var sub = dad.children('li').slice(index);
					dad.after($('<ul></ul>').append(sub));
				}
			}
		});
	};
	that.init = function() {
		//Update your selector to suit
		that.container = $('.split_it');
		if(that.container.length > 0) {
			that.setup();
		}
	};
	return that;
})();