modeline needs to be set for it to work
Note that in order for vim modelines to work, you must have the ‘modeline’ option set, i.e. :set modeline. Do a :help modeline for more info.
Posts tagged with filetype
Vim modelines
If vim does not detect a filetype correctly, then you can add a modeline at the top of the file (first or second line, I think), which tells vim the filetype...