Dynamically create polymer element

Question

I have defined login element as follows:

Answer 1

factory MyLogin() => document.createElement("form", "my-login");

Then you can just call:

MyLogin login = new MyLogin();

This works for me.

Answer 2

You should instantiate it as

Element y = new Element.tag('form', 'my-login');

What seems not to work is

MyLogin y = new Element.tag('form', 'my-login');

this should result in the HTML for the inserted element

<form is="my-login"></form>