var formatCollection function function findNode id data for var index

var formatCollection = (function () {

    function findNode(id, data) {
        for (var index = 0; index < data.length; index++) {
            if (data[index].id == id) {
                return data[index].children;
            } else {
                var children = data[index].children;
                var node = findNode(id, children);
                if (node) {
                    return node;
                }
            }
        }
    }

    function makeCollection(nodes, results) {

        nodes = _.sortBy(nodes, function (node) {
            return node['item'].position;
        });

        _.forEach(nodes, function (node) {
            results.push(node.item);
            makeCollection(node.children, results);
        });
    }

    return function (collection) {

        var data = [
            {
                id: 0,
                children: []
            }
        ];

        while (collection.length > 0) {
            var item = collection.shift();
            var node = findNode(item.parentId || 0, data);
            if (node) {
                node.push({
                    id: item.id,
                    item: item,
                    children: []
                });
            } else {
                collection.push(item);
            }
        }

        var formattedCollection = [];
        makeCollection(data[0].children, formattedCollection);

        return formattedCollection;
    };
})();