How to make a file with .pt extension, with xml syntax highlighting and vim's plugin snipmate load pt.snippets?

I have the following in my .vimrc:

au BufNewFile,BufRead *.pt set filetype=xml

This is needed because although I'm editing a file with *.pt extension, it's indeed a valid xml file: setting the filetype like this I can have syntax highlighting.

I'm using vim's snipmate plugin, and tried to create pt.snippets to specific needs since these files are Zope Page Templates (ZPT with TAL).

Now, I have a problem: I don't want to create these snippets in xml.snippets, since they aren't really generic xml snippets, but my *.pt files are set to xml, so when I define my pt snippets they aren't loaded 开发者_开发知识库unless I run :set filetype=pt on my pt file on vim - but then I lose syntax highlighting.

I would like to be able to have a pt file, with xml syntax highlighting, to be able to load a pt.snippets file from snipmate. How can I do it?

(I would like to avoid putting my snippets in a generic snippet file, I would like it to be present only in pt.snippets to be easier to maintain.)

the syntax is notoriously finnicky for not wanting to support two concurrent filetypes (actually, someone asked this same question yesterday)

au BufRead *.pt set filetype=xml.pt
au BufNewFile *.pt set filetype=xml.pt

jinfield's answer is actually spot-on, but I have had the comma-syntax fail on some versions of vim

Snipmate allows for dotted 'filetype' syntax, try:

au BufNewFile,BufRead *.pt set filetype=xml.pt

How about?:

autocmd BufNewFile,BufRead *.pt setlocal filetype=pt
autocmd BufNewFile,BufRead *.pt setlocal syntax=xml