PartialsLoader.php

<?php

class PartialsLoader implements ArrayAccess {

	protected $baseDir;
	protected $extensions = array('mustache', 'stache', 'ms');
	protected $partials = array();

	public function __construct($baseDir = null) {
		$this->baseDir = (isset($baseDir)) ? $baseDir : dirname(__FILE__);
	}

	public function offsetExists($offset) {
		return ($this->findPartial($offset) !== null);
	}

	public function offsetSet($offset, $value) {
		throw new InvalidArgumentException('PartialsLoader is read-only o_O');
	}

	public function offsetUnset($offset) {
		throw new InvalidArgumentException('PartialsLoader is read-only o_O');
	}

	public function offsetGet($offset) {
		if (!isset($this->partials[$offset])) {
			$this->partials[$offset] = $this->loadPartial($offset);
		}
		return $this->partials[$offset];
	}

	protected function findPartial($name) {
		foreach ($this->extensions as $ext) {
			$filename = sprintf("%s/%s.%s", $this->baseDir, $name, $ext);
			if (file_exists($filename)) {
				return $filename;
			}
		}
	}

	protected function loadPartial($name) {
		$filename = $this->findPartial($name);
		
		if ($filename === null) {
			throw new UnknownPartialExtension(sprintf(
				'Partial template %s does not exist in %s', $offset, $this->baseDir
			));
		}

		return file_get_contents($filename);
	}
}