service model example for CakePHP

app_controller.php

<?php

class AppController extends Controller {

	var $uses = array('Service');

}

app_shell.php

<?php

class AppShell extends Shell {

	var $uses = array('Service');

	function postByEmail() {
		$data = array(); // some email receiving process
		return $data;
	}

}

article.php

<?php

class Article extends AppModel {
	function add() {
	}
}

article_shell.php

<?php

App::import('Shell', 'AppShell');

class ArticleShell extends AppShell {

	function add() {
		$data = $this->postByEmail();
		if (!$this->Service->saveNewArticle($data)) {
			$this->log($data);
			// delivering failed notice email
		}
	}

}

articles_controller.php

<?php

class ArticlesController extends AppController {

	function add() {
		if (!empty($this->data)) {
			if ($this->Service->saveNewArticle($this->data)) {
				$this->Session->setFlash(__('Article has been saved.', true));
				$this->redirect(array('action' => 'index'));
			} else {
				$this->Session->setFlash(__('Article was not saved. Please, try again.', true));
			}
		}
	}

}

service.php

<?php

class Service extends Overloadable2 {

	function get__($name) {
		return $this->$name = ClassRegistry::init($name);
	}

	function set__($name, &$val) {
		return $this->$name =& $val;
	}

	function saveNewArticle($data) {
		return $this->Article->add($data);
	}

}

service.test.php

<?php

App::import('Model', 'Article');

Mock::generate('Article');

class ServiceTest extends CakeTestCase {

	function startTest() {
		$Article =& ClassRegistry::init('MockArticle');
		ClassRegistry::addObject('Article', $Article);
		$this->Service = ClassRegistry::init('Service');
	}

	function endTest() {
		unset($this->Service);
		ClassRegistry::flush();
	}

	function testSaveNewArticle() {
		$this->Service->Article->expectOnce('add');
		$this->Service->saveNewArticle(array(
			'title' => 'test title',
			'body' => "test\nbody",
		));
	}

}