Open a file in Visual Studio's CSS Source Editor

Question

I am using Phil Haack's T4CSS T4 template based on .less

One bad thing about Phil's solution is that visual studio opens the .less files as plain text files rather than as css files. (Thus no intellisense.)

How can I get VS to open a .less file in the CSS Source Editor?

I've tried:

1. Right Click > Open With, but the CSS Source Editor isn't listed.
2. Tools > Options > Text Editor > File Extensions, but once again, CSS Source Editor isn't listed.

Can this be done?

Answer 1

I just posted an extension that does this; you can download it from the Visual Studio Gallery.

The key to the extension is the .pkgdef file:

[$RootKey$\Languages\File Extensions\.less] @="{A764E898-518D-11d2-9A89-00C04F79EFC3}"  [$RootKey$\Editors\{A764E89A-518D-11d2-9A89-00C04F79EFC3}\Extensions] "less"=dword:00000028 

Note that this extension doesn't do anything to help the CSS language service support Less; nested rules, for example, don't work very well at all (it confuses the CSS language service).