How to catch the completion of rendering a template change?

Question

Angular

I have a search field in the template, when you enter, there is a request to issue a large list, which is then drawn in the same template.
I'm having a problem changing the readonly status of the search field while an http request is in progress. I connected it with the status of the request, when the request ends, I change readonly to false, but the list has not yet been drawn, because the list is drawn quite difficult, because of this there is a problem, there is no list yet, but the search field is already editable.
How to hang a handler to complete the display of template changes?