- Complex report optimization
- Max rate calculation optimization

- Login filtering
- Complex enter key behaviour
- Process loading icon

Client js tried to get (incorrectly) discipline id from URL and got error at the server side.

See `discipline/666/teachers` page.

Ternary operator is left-associated in PHP (right in C++), so we have:
    (...) ? one : second;

I have put an extra braces to improve the evaluation order.

Look at office/ page

it-lab/grade#29 (comment 111)