Check that currentView exists before accessing its children

Fixes #563

Signed-off-by: Ryan O'Hara <oharar@email.chop.edu>
Merge pull request #566 from ryanjohara/issue-563

Check that currentView exists before accessing its children
Port all remaining models from coffee to javascript

Signed-off-by: Don Naegely <naegelyd@gmail.com>