Parser and if statement

It works without parser, but as I said I have to use parser .

Beside twig, which template engine also I should consider?

I use Blade from Laravel. Very very easy to integrate into CI, up to date, and has a ton of features to help you out (Template inheritance, auto escaping...)

Codeigniter is simply one of the tools you need to learn to be a successful developer. Always add more tools to your coding arsenal!