HAML安装

First of all, you need to install the Haml gem. Most people will just want to use the most recent stable release. To get it, just run

gem install --no-ri haml

If you want to use the latest and greatest stuff in Haml, though, you'll need to install it from Git. To do so, run

git clone git://github.com/nex3/haml.git
cd haml
rake install

赋予程序方法
haml --rails path/to/app

还有要注意的就是
写完的文件保存为.haml
RAILS会自动在VIEW中寻找对应controller的HAML的