Installation

1. Create app/models/behaviors/uuid.php using the code provided in the behavior section below.

Usage

Add the behavior name to the $actsAs array for your model. For example, let's assume you have a model named Post (which maps to a database table named posts). Edit your app/models/post.php file and add $actsAs as follows:

Model Class:

<?php 
class Post extends AppModel {
    var $name = 'Post';
    var $actsAs = array('Uuid' => array('field' => 'id'));
}
?>
That's all there is to it. When you use the function save() in your model (native CakePHP function) the behavior will add a UUID to the field specified. The field can be any you choose and defaults to id.

The field you choose to set a UUID on will need to be configured appropriately in your database. For instance my id column definition in MySQL looks like: `id` char(36) NOT NULL

Behavior

Here's the code for the behavior. Save this as a file named uuid.php in your app/models/behaviors folder.

<?php
/**
 * UUID Behavior class file.
 *
 * Model Behavior to support adding UUID's when a record is saved.
 *
 * This behavior implements the beforeSave() callback for updating the
 * specified field with a UUID. The actual randomness of the generated
 * UUID has not been tested. Use at your own risk.
 *
 * Usage in model:
 *
 * Add Uuid to the $actsAs array of your model:
 * var $actsAs = array('Uuid' => array('field' => 'id'));
 *
 * @filesource
 * @package     app
 * @subpackage  models.behaviors
 */

/**
 * Add UUID behavior to a model.
 *
 * @author      Billy Gunn
 * @package     app
 * @subpackage  models.behaviors
 */
class UuidBehavior extends ModelBehavior {
    /**
     * Default model settings
     */
    var $defaultSettings = array('field' => 'id');

    /**
     * Initiate behaviour for the model using settings.
     *
     * @param object $model    Model using the behaviour
     * @param array $settings    Settings to override for model.
     *
     * @access public
     */
    function setup(&$model, $settings = array()) {
        $field = $this->defaultSettings['field'];

        if (!empty($settings['field'])) {
            $field = $settings['field'];
        }

        if ($model->hasField($field)) {
            $this->settings[$model->name] = array('field' => $field);
        }
    }

    /**
     * Generates a pseudo-random UUID.
     * Slightly modified version of a function submitted to php.net:
     * http://us2.php.net/manual/en/function.com-create-guid.php#52354
     *
     * @access public
     */
    function uuid() {
        if (function_exists('com_create_guid')) {
            return com_create_guid();
        } else {
            mt_srand((double)microtime()*10000);
            $charid = md5(uniqid(rand(), true));
            $hyphen = chr(45);// "-"
            $uuid = substr($charid, 0, 8).$hyphen
                  . substr($charid, 8, 4).$hyphen
                  . substr($charid,12, 4).$hyphen
                  . substr($charid,16, 4).$hyphen
                  . substr($charid,20,12);

            return $uuid;
        }
    }

    /**
     * Run before a model is saved to add a UUID to a field.
     *
     * @param object $model    Model about to be saved.
     *
     * @access public
     */
    function beforeSave(&$model) {
        if ($this->settings[$model->name]) {
            $field = $this->settings[$model->name]['field'];
            if (!isset($model->data[$model->name][$field])) {
                $model->data[$model->name][$field] = $this->uuid();
            }
        }
    }
}
?>


Test Case

If you haven't already, read Testing Models with CakePHP 1.2 test suite as a starting point for getting your test environment configured.

Before continuing you should have the Uuid behavior and your test environment installed and working. Create a file named uuid_test_fixture.php in the app/tests/fixtures folder with the following contents.


<?php
/**
 * Uuid Behavior test fixture class file.
 *
 * Fixture for tests in uuid Behavior.
 *
 * @filesource
 * @package     app
 * @subpackage  app.tests.fixtures
 */

/**
 * Fixture used in tests for the Uuid behavior.
 *
 * @author      Billy Gunn
 * @package     app
 * @subpackage  app.tests.fixtures
 */
class UuidTestFixture extends CakeTestFixture {
        var $name = 'UuidTest';
        var $fields = array('id' => array('type' => 'integer', 'key' => 'primary'),
                            'uuid' => array('type' => 'string', 'null' => false, 'length' => 36),
                            'name' => array('type' => 'string', 'null' => false),
                            'description' => array('type' => 'string', 'null' => false),
                            'created' => 'datetime',
                            'updated' => 'datetime'
        );

        var $records = array(
                array ('id' => 1, 'uuid' => '758372bc-6fd4-102a-ae1c-00065becda85', 'name' => 'First record', 'description' => 'First record', 'created' => '2007-03-18 10:39:23', 'updated' => '2007-03-18 10:41:31')
        );
}
?>

Next, create a file called uuid.test.php in the app/tests/cases/behaviors folder with the following contents.


<?php
/**
 * Uuid Behavior test case.
 *
 * Test cases for Uuid Behavior.
 *
 * @filesource
 * @package     app
 * @subpackage  app.tests.cases.behaviors
 */

/**
 * Model used in tests for Uuid.
 *
 * @author      Billy Gunn
 * @package     app
 * @subpackage  app.tests.cases.behaviors
 */
class UuidTest extends CakeTestModel {
        var $name = 'UuidTest';
        var $actsAs = array('Uuid' => array('field' => 'uuid'));
}

/**
 * Uuid Behavior test case.
 *
 * @author      Billy Gunn
 * @package     app
 * @subpackage  app.tests.cases.behaviors
 */
class UuidTestCase extends CakeTestCase {

        var $fixtures = array( 'uuid_test' );

    /**
     * testCreateRecord
     *
     * Create a new record and verify that a valid uuid
     * was added to the the uuid field.
     *
     * @access public
     * @return void
     */
    function testCreateRecord() {

        $this->Record =& new UuidTest();

        $data = array('UuidTest' => 
                   array('id' => 4, 
                         'uuid' => null, 
                         'name' => 'New record')
                );

        $this->Record->save($data);

        $result = $this->Record->read(null, 4);

        $match = preg_match("/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/", $result['UuidTest']['uuid']);

        $this->assertEqual($match, 1);
    }


    /**
     * testUpdateRecord
     *
     * An existing record should not have its uuid updated on save
     *
     * @access public
     * @return void
     */
    function testUpdateRecord() {

        $this->Record =& new UuidTest();

        $data = array('UuidTest' => array ( 'id' => 1, 'uuid' => '758372bc-6fd4-102a-ae1c-00065becda85', 'description' => 'modified record'));
        $this->Record->save($data);

        $result = $this->Record->findAll(null, array('id', 'uuid', 'name', 'description'));

        $expected = array(
                array('UuidTest' => array(
                      'id' => 1,
                      'uuid' => '758372bc-6fd4-102a-ae1c-00065becda85',
                      'name' => 'First record',
                      'description' => 'modified record'
                ))
       );

       $this->assertEqual($result, $expected);
    }
}
?>

Point your browser to: http:///test.php. Once there, click on App Test Cases, and then look for the option behaviors/uuid.test.php and click it. You will see the results of the test in your browser.