LaTeX.org

So, I finally found what I was looking for. In the 'Options' menu just left of the 'Help' menu, there is an option "Define Current Document as 'Master Document'".

Hello,

I was just wondering if it was possible to compile from within a subfile of a long document. Is there a way to set the main/root file? Or must I return to the main file, save all, and then compile from there each time?

Thanks!