Dropdown

Standard example:

@models = Model.all
select_tag "models", options_from_collection_for_select(@models, "id", "name"), {}

This will generate the following HTML: David

The last argument are options, which accepts the following:

{
     multiple: false, 
     disabled: false, 
     include_blank: false, 
     prompt: false
}

More examples can be found: http://apidock.com/rails/ActionView/Helpers/FormTagHelper/select_tag