HamlPy

HamlPy (pronounced "haml pie") is a tool for Django developers who want to use a Haml like syntax for their templates. HamlPy is not a template engine in itself but simply a compiler which will convert HamlPy files into templates that Django can understand.

But wait, what is Haml? Haml is an incredible template engine written in Ruby used a lot in the Rails community. You can read more about it here.

Installing

Stable release

The latest stable version of HamlPy can be installed using setuptools easy_install hamlpy or pip (pip install hamlpy)

Development

The latest development version can be installed directly from GitHub:

pip install https://github.com/jessemiller/HamlPy/tarball/master

Syntax

Almost all of the XHTML syntax of Haml is preserved.

#profile
	.left.column
		#date 2010/02/18
		#address Toronto, ON
	.right.column
		#bio Jesse Miller

turns into..

<div id='profile'>
	<div class='left column'>
		<div id='date'>2010/02/18</div>
		<div id='address'>Toronto, ON</div>
	</div>
	<div class='right column'>
		<div id='bio'>Jesse Miller</div>
	</div>
</div>

The main difference is instead of interpreting Ruby, or even Python we instead can create Django Tags and Variables

%ul#athletes
	- for athlete in athlete_list
		%li.athlete{'id': 'athlete_{{ athlete.pk }}'}= athlete.name

turns into..

<ul id='athletes'>
	{% for athlete in athlete_list %}
		<li class='athlete' id='athlete_{{ athlete.pk }}'>{{ athlete.name }}</li>
	{% endfor %}
</ul>

Usage

Option 1: Template loader

The template loader was originally written by Chris Hartjes under the name 'djaml'. This project has now been merged into the HamlPy codebase.

Add the HamlPy template loaders to the Django template loaders:

TEMPLATE_LOADERS = (
    'hamlpy.template.loaders.HamlPyFilesystemLoader',
    'hamlpy.template.loaders.HamlPyAppDirectoriesLoader',   
    ...
)

If you don't put the HamlPy template loader first, then the standard Django template loaders will try to process it first. Make sure your templates have a .haml or .hamlpy extension, and put them wherever you've told Django to expect to find templates (TEMPLATE_DIRS).

Template caching

For caching, just add django.template.loaders.cached.Loader to your TEMPLATE_LOADERS:

TEMPLATE_LOADERS = (
    ('django.template.loaders.cached.Loader', (
	    'hamlpy.template.loaders.HamlPyFilesystemLoader',
	    'hamlpy.template.loaders.HamlPyAppDirectoriesLoader',
	    ...
    )),   
)

Settings

Following values in Django settings affect haml processing:

• HAMLPY_ATTR_WRAPPER -- The character that should wrap element attributes. This defaults to ' (an apostrophe).

Option 2: Watcher

HamlPy can also be used as a stand-alone program. There is a script which will watch for changed hamlpy extensions and regenerate the html as they are edited:

    usage: hamlpy-watcher [-h] [-v] [-i EXT [EXT ...]] [-ext EXT] [-r S]
                        [--tag TAG] [--attr-wrapper {",'}]
                        input_dir [output_dir]

    positional arguments:
    input_dir             Folder to watch
    output_dir            Destination folder

    optional arguments:
    -h, --help            show this help message and exit
    -v, --verbose         Display verbose output
    -i EXT [EXT ...], --input-extension EXT [EXT ...]
                            The file extensions to look for
    -ext EXT, --extension EXT
                            The output file extension. Default is .html
    -r S, --refresh S     Refresh interval for files. Default is 3 seconds
    --tag TAG             Add self closing tag. eg. --tag macro:endmacro
    --attr-wrapper {",'}  The character that should wrap element attributes.
                            This defaults to ' (an apostrophe).
    --jinja               Makes the necessary changes to be used with Jinja2

Or to simply convert a file and output the result to your console:

hamlpy inputFile.haml

Or you can have it dump to a file:

hamlpy inputFile.haml outputFile.html

Optionally, --attr-wrapper can be specified:

hamlpy inputFile.haml --attr-wrapper='"'

Using the --jinja compatibility option adds macro and call tags, and changes the empty node in the for tag to else.

For HamlPy developers, the -d switch can be used with hamlpy to debug the internal tree structure.

Create message files for translation

There is a very simple solution.

django-admin.py makemessages --settings=<project.settings> -a

Where:

• project.settings -- Django configuration file where module "hamlpy" is configured properly.

Reference

Check out the reference.md file for a complete reference and more examples.

Status

HamlPy currently:

• has no configuration file. which it should for a few reasons, like turning off what is autoescaped for example
• does not support some of the filters yet

Contributing

Very happy to have contributions to this project. Please write tests for any new features and always ensure the current tests pass. You can run the tests from the hamlpy/test folder using nosetests by typing

nosetests *.py