VIM folding for ERB files?

Vim noob here. I have code folding working in most places, via indent mode, but for some reason I cannot get Vim to fold .html.erb files in ruby... even with indents.

Here's the relevant region of my vimrc. Is there something else I need to do to make Vim aware of the erb files? Is it possible to customize my folding per file type?

I'm running all the Janus plugins, so have rails.vim, etc. all installed.

let ruby_fold=1
set foldmethod=indent
set foldcolumn=0
set foldlevel=99
nnoremap <space> za<cr>

It's a difficult question, because there's probably something in your vim configuration that inhibits folding and I, for example, can't reproduce it. But I can suggest a few things you could try.

First of all, check what the values of those settings are in the actual buffer. Meaning, open up an erb file and check if the settings are correct. In order to do that, you can type, for example, set foldmethod, which will echo the current value of foldmethod to the screen. If one of the settings doesn't match the ones in your .vimrc, then that might be the problem.

Also, see if the file really does have the "eruby" filetype. If it's not displayed in your statusline, you could check that with set filetype.

Most importantly, one way of customizing settings per filetype is by creating a file with the filetype's name inside the ~/.vim/ftplugin directory. In your case, you can create the file ~/.vim/ftplugin/eruby.vim and put any filetype-specific settings in it. Setting them with setlocal instead of set will keep them local to the file. If it turns out the settings for erb are off, you can "fix" them by putting the values you want there.