Experiment with integration bootstrap forms with knockout and rails.
Add label options and bind to knockout.
Redesign form interface.
Handle many errors.
Refactoring.
Refactoring part2.
Add knockout mapping plugin.
Add submit button.
Send json to controller.
Bilding data tree for form from basic model tree.
Data in subsection works now.
Read data from instance variable and transform it using mapping.
Pass authenticity token as one of the params.
Added messages above the form.
First level errors support.
Errors works in subsection as well.

But you need set errors on base model.
Refactoring of form_for.
Content for is prety usefull.
Refactor model inside form.
Move js to assets and more refactoring.