DEMO: Action helper. No more data-user-id needed.

[smfoote]

Because the listener has the context/model within closure scope, no need to do model lookups when the event happens.

[prashn64]

Let me know if this would be useless, but maybe you could allow binding to a different context:

let boundContext = params.context || context;
frag.querySelector(selector).addEventListener(type, context[method].bind(boundContext));