# \[ANN\] Haml 1.5!

**URL:** <https://www.ruby-forum.com/t/ann-haml-1-5/89095>\
**Category:** Rails\
**Created:** [March 17, 2007, 6:10am UTC](https://www.ruby-forum.com/t/ann-haml-1-5/89095 "2007-03-17T06:10:29Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![nex3](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ed8c4c/32.png) [@nex3](https://www.ruby-forum.com/u/nex3)\
**Post date:** [March 17, 2007, 6:10am UTC](https://www.ruby-forum.com/t/ann-haml-1-5/89095/1 "2007-03-17T06:10:29Z")

</div>

Haml 1.5 has been released! Download the new version and give it a  
try.

For Rails: “./script/plugin install  
[http://svn.hamptoncatlin.com/svn/haml/tags/stable](http://svn.hamptoncatlin.com/svn/haml/tags/stable)”  
Standalone: “gem install haml”

For those of you who don’t know about Haml, it’s a very snazzy  
templating engine that can be used as a replacement for ERb/RHTML.  
Rather than just shoving Ruby code into XHTML, Haml actually creates  
an abstraction on top of the XHTML document, using whitespace instead  
of repetitive start and end tags to denote structure. For more  
information, check out the Haml tutorial at  
[http://haml.hamptoncatlin.com/docs](http://haml.hamptoncatlin.com/docs).

So what’s new in 1.5? Along with plenty of bug fixes, version 1.5 adds  
various useful and snazzy features to Haml. But the biggest news in  
1.5 isn’t a new feature: it’s an entirely new templating engine.

You see, after using Haml for a while, one tends to get used to the  
idea that markup can, indeed /should/, be beautiful and concise.  
Other, less elegant markup languages begin to seem a little grating.  
While working on a stylesheet, one might think “I can right HTML in an  
elegant manner. Why can’t I do the same thing with CSS?” Well, we  
thought that, too. So we came up with a solution: Syntactically  
Awesome StyleSheets, or “Sass.”

Sass is a templating engine for CSS that’s bundled along with Haml  
1.5. It allows you to write CSS using the same elegant whitespace-  
sensitive style used in Haml. It eliminates the redundancy formerly  
inherent in nesting CSS styles, using “namespace” styles such as font-  
family and font-weight, re-using the same value, and even writing out  
CSS rules. Just stick your “.sass” files in “public/stylesheets/sass”,  
and corresponding “.css” files will be created whenever you need them  
to be. You can read all about it at  
[http://haml.hamptoncatlin.com/docs/sass](http://haml.hamptoncatlin.com/docs/sass),  
but here’s a sample to get you interested:

!main\_color = #82fc08

#main  
:width 80%  
:color = !main\_color  
:font  
:family sans-serif  
:size 1.3em

p  
:color = !main\_color - #404040  
:font-size 0.8em

This compiles to

#main {  
width: 80%;  
color: #82fc08;  
font-family: sans-serif;  
font-size: 1.3em; }  
#main p {  
color: #42bc00;  
font-size: 0.8em; }

Now, of course Sass is all exciting and wonderful, but what about  
those new Haml features I was mentioning? Well, they’re delightful as  
well. For instance, Haml now does error handling. Before 1.5, invalid  
input wouldn’t cause an error; it would just produce undefined, often  
very strange, output. This was the cause of many confusing issues for  
many people, even those of us who created Haml. Haml 1.5, however,  
checks for syntax errors, and will notify you exactly what went wrong  
and where in the document the error occurred, in a way that Rails can  
then format as a good old error page.

Haml 1.5 also adds a new type of command: filters, which use the “:”  
character followed by the name of the filter. Filters take an indented  
block of text and pass it through some sort of text processor,  
independent of Haml, and insert the result (as properly indented as  
possible) into the Haml document. For example, if you wanted to add  
some “humane” markup to your document using Textile, you could do:

.content  
:textile  
h1. Blah!

```
 Blah. Blah blah blah blah, blah blah blah.
 *Blah* blah blah, blah bl-blah blah blah.

 _Blah_ blah blah blah.

```

This would compile to:

# Blah!

Blah. Blah blah blah blah, blah blah blah.

**Blah** blah blah, blah bl-blah blah blah.

_Blah_ blah blah blah.

There are lots of predefined filters, including:

- :plain doesn’t parse the text at all, allowing you to put “.” and  
other Haml-significant characters at the beginning of a line without  
escaping them with a backslash.
- :ruby interprets the text as Ruby code, and inserts all output  
printed to stdout into the Haml document.
- :preserve preserves all whitespace in the text, even at the  
beginning of lines.
- :erb parses the text with ERb, the engine used for RHTML.
- :sass parses the text with Sass, of course.
- :textile and :markdown run the respective text interpreters over  
the text. :textile is only available if the RedCloth gem is  
installed; :markdown is available if either RedCloth or BlueCloth is  
installed.

The introduction of filters also means that the use of the “~”  
character to denote a nested block of whitespace-sensitive text is now  
entirely redundant. As such, we’ve deprecated it; it’s still usable in  
1.5, but a warning will pop up, and it will be removed in the next  
version. The :preserve filter should be used instead. The other use of  
the “~” character, to preserve the whitespace in “

```
” and
“” tags output by functions, is still available.

Enjoy!
```

- Nathan