Angular2 toggle/open ng2-select dropdown

Angular 4.3+ I am using ng2-select dropdown. I want the drop down to be opened on some event. I want to trigger the event that would open the drop down. Dropdown:

Angular2: Cloning component / HTML element and it’s functionality

So, the question is fairly simple… I have a table and some angular logic on it (calculating styles, etc)… specifically I have this on THs [class.hidden] = “ !== ‘key-data’ && …