A wrapper for less.php to integrate LESS into SilverStripe.

• Integrates less.php http://lessphp.gpeasy.com/ seemessly into SilverStripe
• Based on lesscss from https://github.com/tardinha/silverstripe-lesscss
• Includes flushing option (?flush=1) to regenerate CSS stylesheets (ie. force undetected less changes with @import)
• Check all required *.css files for a *.less equivalent, so works transparently.
• Allows custom global variables to be passed through to less compiling
• Automatic image & @import URL translation (eg: url('../image.png') will get rewritten as url('/path/to/image.png') depending on your website's root folder)
• Automatic compression of CSS files when in Live mode (may require an initial ?flush)

• SilverStripe 2 or 3
• Webserver must have read & write permissions to the directories containing the *.less files to write compiled css files

You can refer to your less files either by its "LESS name" (eg:stylesheet.less) or "CSS name" (eg:stylesheet.css) - the parser will check to see if there is a less file for all css files included.

In your controller you can:

Simply refer to your files as *.css files. This ensures that cache is always used (unless a ?flush is run), using filemtime() in "live" move (fastest), and Less_Cache in "dev" mode.

class Page_Controller extends ContentController {

	public function init() {
		parent::init();
		/* The parser will find css/stylesheet[1-3].less files are compile those */
		$css[] = $this->ThemeDir() . '/css/stylesheet1.css';
		$css[] = $this->ThemeDir() . '/css/stylesheet2.css';
		$css[] = $this->ThemeDir() . '/css/stylesheet3.css';
		Requirements::combine_files('combined.css', $css);
		Requirements::process_combined_files();
	}

}

You can optionally use the *.less names. Note: this option forces the use of Less_Cache in both "live" and "dev" modes.

class Page_Controller extends ContentController {

	public function init() {
		parent::init();
		if ( Director::isDev() ){
			Requirements::css($this->ThemeDir() . '/css/stylesheet1.less');
			Requirements::css($this->ThemeDir() . '/css/stylesheet2.less');
			Requirements::css($this->ThemeDir() . '/css/stylesheet3.less');
		} else {
			/* combined.less simply includes a merged list of the above stylesheets
			 * in the same order as above:
			 * @import "stylesheet1";
			 * @import "stylesheet2";
			 * @import "stylesheet3";
			*/
			Requirements::css($this->ThemeDir() . '/css/combined.less');
		}
	}

}

or you can call it directly from your template file:

    <% require css(themes/mytheme/css/stylesheet.less) %>

By default silverstripe-lesscss includes one custom global variable ThemeDir which you are able to use in your less files:

div {
    background: url('@{ThemeDir}/images/icon-menu.png') no-repeat top center;
}

@{ThemeDir} will get substituted with "Director::baseURL() . SSViewer::get_theme_folder()".

You can add optionally your own global variables to your mysite/_config.php:

LessCompiler::addVariable("StandardFont", "Arial, helvetica, sans-serif");
LessCompiler::addVariable("BaseURL" => "'http://example.com/'");
// note the double-quote, see below...

Note: Be aware that the value of the variable is a string containing a CSS value. So if you want to pass a LESS string in, you're going to need two sets of quotes. One for PHP and one for LESS. If you get the error "less.php fatal error: failed to parse passed in variable" then you probably need to add extra quoted to your value.