Pass data from router into template helper

How can data from Router.route be passed onto a template helper. So I want to use a user _id from my iron router to be used in my template helper to get documents for that particular user. This is the code: {
    this.route('/user/:_id', {
    template: 'userPage',
    data: function(){
        var currentList = this.params._id;
        return Meteor.users.findOne({ _id: currentList });

So how can the currentUser in the templates.js file be assigned with the value of currentList from the routes.js file?

    name: function () {
        var currentUser = this.currentList; 
        var user = Meteor.users.findOne({ _id: currentUser });
        return user.usernamex;

Currently it returns undefined


FWIW the following says that is deprecated…

Thanks…I’ll make the changes from