Federico Cargnelutti

Simple is better than complex. Complex is better than complicated. | @fedecarg

Testing Zend Framework Action Controllers With Mocks

with 5 comments

In this post I’ll demonstrate a unit test technique for testing Zend Framework Action Controllers using Mock Objects. Unit testing controllers independently has a number of advantages:

  1. You can develop controllers test-first (TDD).
  2. It allows you to develop and test all of your controller code before developing any of the view scripts.
  3. It helps you quickly identify problems in the controller, rather than problems in one of the combination of Model, View and Controller.

The Action Controller I’m going to test has only one method, profileAction():

tests/application/controllers/UserController.php

class UserController extends Zend_Controller_Action
{
    public function profileAction()
    {
        $this->view->userId = $this->_getParam('user_id');
        return $this->render();
    }
}

tests/application/ControllerTestCase.php

class ControllerTestCase extends Zend_Test_PHPUnit_ControllerTestCase
{
    public $application;

    public function setUp()
    {
        $this->application = new Zend_Application(
            APPLICATION_ENV,
            APPLICATION_PATH . '/config/application.ini'
        );

        $this->bootstrap = array($this, 'bootstrap');
        parent::setUp();
    }

    public function tearDown()
    {
        Zend_Controller_Front::getInstance()->resetInstance();

        $this->resetRequest();
        $this->resetResponse();

        $this->request->setPost(array());
        $this->request->setQuery(array());
    }

    public function bootstrap()
    {
        $this->application->bootstrap();
    }
}

tests/application/controllers/UserControllerTest.php

require_once TESTS_PATH . '/application/ControllerTestCase.php';
require_once APPLICATION_PATH . '/controllers/UserController.php';

class UserControllerTest extends ControllerTestCase
{
    public function testStubRenderMethodCall()
    {
        $request = $this->getRequest()
            ->setRequestUri('/user/profile/1')
            ->setParams(array('user_id'=>1))
            ->setPathInfo(null);

        $response = $this->getResponse();

        $this->getFrontController()
            ->setRequest($request)
            ->setResponse($response)
            ->throwExceptions(true)
            ->returnResponse(false);

        $controller = $this->getMock(
            'UserController',
            array('render'),
            array($request, $response, $request->getParams())
        );
        $controller->expects($this->once())
                 ->method('render')
                 ->will($this->returnValue(true));

        $this->assertTrue($controller->profileAction());
        $this->assertTrue($controller->view->user_id == 1);
    }
}

You can go further making both the tests and the implementation more sophisticated. The main point is that you can build and test a controller in a way that doesn’t require a view script to be written to do so.

Zend Framework Known Issues

By default Zend_Test_PHPUnit_ControllerTestCase sets the redirector exit value to false, leading to unexpected behavior when unit testing your code. For that reason, make sure you always add a return statement after calling a utility method:

class UserController extends Zend_Controller_Action
{
    public function profileAction()
    {
        if (null == $this->_getParam('user_id', null) {
            return $this->_redirect('/');
        }
        return $this->render();
    }
}

If you want the Front Controller to throw exceptions, you have no other choice than to overwrite the dispatch method and pass a boolean TRUE to the throwExceptions() method:

class ControllerTestCase extends Zend_Test_PHPUnit_ControllerTestCase
{
    ...

    public function dispatch($url = null)
    {
        // redirector should not exit
        $redirector = Zend_Controller_Action_HelperBroker::getStaticHelper('redirector');
        $redirector->setExit(false);

        // json helper should not exit
        $json = Zend_Controller_Action_HelperBroker::getStaticHelper('json');
        $json->suppressExit = true;

        $request = $this->getRequest();
        if (null !== $url) {
            $request->setRequestUri($url);
        }
        $request->setPathInfo(null);

        $this->getFrontController()
             ->setRequest($request)
             ->setResponse($this->getResponse())
             ->throwExceptions(true)
             ->returnResponse(false);

        $this->getFrontController()->dispatch();
    }

    ...
}

The Dispatcher not only violates the DRY principle but also suffers from amnesia. The problem is that it doesn’t store the instance of the Action Controller, instead, it destroys it (Zend_Controller_Dispatcher_Standard Line 305). You can easily get around this issue by extending the standard dispatcher and overwriting the dispatch() method:

class Zf_Controller_Dispatcher_Standard extends Zend_Controller_Dispatcher_Standard
{
    ...

    public function dispatch($url = null)
    {
        ...
        Zend_Registry::set('Zend_Controller_Action', $controller);

        // Destroy the page controller instance and reflection objects
        $controller = null;
    }

This allows you to access the view object after dispatching the request:

class ExampleControllerTest extends ControllerTestCase
{
    public function testDefaultActionRendersViewObject()
    {
        $this->dispatch('/');

        $controller = Zend_Registry::get('Zend_Controller_Action');

        $this->assertEquals('ExampleController', get_class($controller));
        $this->assertTrue(isset($controller->view));
    }

Links

PHPUnit: Testing Zend Framework Controllers
PHPUnit: Mock Objects

Written by Federico

November 1, 2009 at 1:33 pm

Symfony 1.3 Web Application Development

with 3 comments

Packt Publishing recently sent me a copy of the book “Symfony 1.3 Web Application Development” to review.

This book is not a reference guide, but an example driven tutorial that takes you through the process of building Model-View-Controller-based web applications. You will learn how to create and develop a simple online store application. It also covers best practices for better and quicker application development.

The book is based on the latest version of the Symfony Framework, and does a great job telling you what you get out of the box and how it works, which is perfect for hitting the ground running. During the development you are introduced to the concepts and features of the MVC framework. However, for those who want to know more about the framework, the book doesn’t explain how things work under the covers. This book is more for beginners who want to get started with Symfony 1.3.

One thing I didn’t like about this book is that it uses Propel instead of Doctrine as the default ORM framework. Apart from that, it does a great job explaining and demonstrating with practical examples how to build a Web application from scratch.

Overall, and considering that some of the topics in this book have already been covered in Practical Symfony 1.3, I rate this book 4 out of 5.

Symfony 1.3 Web Application Development

Written by Federico

October 13, 2009 at 11:24 am

Posted in Frameworks, PHP

Database Replication Adapter for Zend Framework Applications

with 10 comments

Database replication is an option that allows the content of one database to be replicated to another database or databases, providing a mechanism to scale out the database. Scaling out the database allows more activities to be processed and more users to access the database by running multiple copies of the databases on different machines.

The problem with monolithic database designs is that they don’t establish an infrastructure that allows for rapid changes in business requirements. Here is where database replication comes into play. Replication can be used effectively for many different purposes, such as separating data entry and reporting, distributing load across servers, providing high availability, etc.

In 2008, Paul M. Jones announced the release of an SQL adapter that allows Solar users to connect to master/slave database installations. My first reaction was: Great! This will inspire other FOSS developers to create similar components. And guess what, it did. I wrote my own ReplicationAdapter. It’s not great, but it’s flexible enough to support the most commonly used replication scenarios:

Single-Master Replication

In the simplest replication scenario, the master copy of directory data is held in a single read-write replica on one server called the supplier server. The supplier server also maintains changelog for this replica. On another server, called the consumer server, there can be multiple read-only replicas.

Configuration array:

$db = array(
    'adapter'        => 'Pdo_Mysql',
    'driver_options' => array(PDO::ATTR_TIMEOUT=>5),
    'username'       => 'root',
    'password'       => 'root',
    'dbname'         => 'test',
    'master_servers' => 1,
    'servers'        => array(
        array('host' => 'db.master-1.com'),
        array('host' => 'db.slave-1.com'),
        array('host' => 'db.slave-2.com')
    )
);

// or ...

$db = array(
    'adapter'        => 'Pdo_Mysql',
    'driver_options' => array(PDO::ATTR_TIMEOUT=>5),
    'dbname'         => 'test',
    'master_servers' => 1,
    'servers'        => array(
        array('host' => 'db.master-1.com', 'username' => 'user1', 'password'=>'pass1'),
        array('host' => 'db.slave-1.com', 'username' => 'user2', 'password' => 'pass2'),
        array('host' => 'db.slave-2.com', 'username' => 'user3', 'password' => 'pass3')
    )
);

Zend_Registry::set('db_config_array', $db);

In the setup above, all writes will go to the master connection and all reads will be randomly distributed across the available slaves.

Multi-Master Replication

This type of configuration can work with any number of consumer servers. Each consumer server holds a read-only replica. The consumers can receive updates from all the suppliers. The consumers also have referrals defined for all the suppliers to forward any update requests that the consumers receive.

$db = array(
    'adapter'        => 'Pdo_Mysql',
    'driver_options' => array(PDO::ATTR_TIMEOUT=>5),
    'username'       => 'root',
    'password'       => 'root',
    'dbname'         => 'test',
    'master_servers' => 2,
    'master_read'    => true,
    'servers'        => array(
        array('host' => 'db.master-1.com'),
        array('host' => 'db.master-2.com')
    )
);

Zend_Registry::set('db_config_array', $db);

Using a distributed memory caching system

Database connections are expensive and it’s very inefficient for an application to try to connect to a server that is down or not responding. A distributed memory caching system can help alleviate this problem by keeping a list of all the failed connections in memory, sharing that information across multiple servers and allowing the application to access it before attempting to open a connection.

To enable this option, you have to register an instance of the Memcached adapter class:

Zend_Registry::set('db_config_array', $db);
...

$cache = Zend_Cache::factory('Core', 'Zend_Cache_Backend_Memcached', $f, $b);
Zend_Registry::set('Zend_Cache', $cache);

Zend Framework Example

Here is a short and simple example of how the ReplicationAdapter might be used in a ZF application:

class SingleMasterDb extends Zf_Db_ReplicationAdapter
{
    public function fecthAll()
    {
        $db = $this->getConnection('slave');
        $query = $db->select()->from('test');
        return $db->fetchAll($query);
    }

    public function insert($data)
    {
        $db = $this->getConnection('master');
        $db->insert('test', $data);
        return $db->lastInsertId();
    }

    public function update($id, $data)
    {
        $db = $this->getConnection('master');
        $where = $db->quoteInto('id = ?', $id);
        return $db->update('test', $data, $where);
    }
}

Source Code:
http://fedecarg.com/repositories/show/zfreplicationadapter

Written by Federico

October 2, 2009 at 3:29 pm

Adding theme support to your Zend Framework application

with 10 comments

This is a brief explanation on how to add theme support to your Zend Framework application and how to ensure those themes are self-contained, easy to distribute and install.

Themes are very powerful and extremely easy to develop. They allow you to quickly switch between layouts and change the look and feel of your application. You can use themes to show, for example, a mobile friendly version of your site.

Making a Zend Framework application theme-able is a three-step process.

First, modify your directory structure:

application/
    controllers/
library/
public/
    themes/
        default/
            css/
            images/
            templates/
        custom/
            css/
            images/
            templates/

Then, edit your Bootstrap class:

class Bootstrap extends Zend_Application_Bootstrap_Bootstrap
{
    protected function _initView()
    {
        $theme = 'default';
        if (isset($this->config->app->theme)) {
            $theme = $this->config->app->theme;
        }
        $path = PUBLIC_PATH.'/themes/'.$theme.'/templates';

        $layout = Zend_Layout::startMvc()
            ->setLayout('layout')
            ->setLayoutPath($path)
            ->setContentKey('content');

        $view = new Zend_View();
        $view->setBasePath($path);
        $view->setScriptPath($baseDir);

        return $view;
    }
}

And finally, copy your view scripts and layouts to the templates directory:

application/
library/
public/
    themes/
        full-site/
            css/
            images/
            templates/
                error/
                index/
                partials/
                layout.phtml
        mobile-site/
            css/
            images/
            templates/

Voila, mission accomplished.

Written by Federico

September 20, 2009 at 10:43 pm

Posted in Frameworks, Open-source, PHP

Zend Framework DAL: DAOs and DataMappers

with 8 comments

A Data Access Layer (DAL) is the layer of your application that provides simplified access to data stored in persistent storage of some kind. For example, the DAL might return a reference to an object complete with its attributes instead of a row of fields from a database table.

A Data Access Objects (DAO) is used to abstract and encapsulate all access to the data source. The DAO manages the connection with the data source to obtain and store data. Also, it implements the access mechanism required to work with the data source. The data source could be a persistent store like a database, a file or a Web service.

And finally, a DataMapper is used to move data between the object and a database while keeping them independent of each other. The DataMapper main responsibility is to transfer data between the two and also to isolate them from each other.

Zend Framework Example

app/
    controllers/
        UserController.php
    views/
lib/
    Project/
        Dao/
            Db/
                User.php
            Service/
                User.php
        DataMapper/
            User.php
        Entity/
            User.php
        Model/
            User.php
    Zf/
        DataSource/
            Dao/
                Mapper.php
        Domain/
            Entity.php
        Db/
            Adapter.php

Database Table Structure

CREATE TABLE `user` (
 `id` int(11) NOT NULL auto_increment,
 `first_name` varchar(100) NOT NULL,
 `last_name` varchar(100) NOT NULL,
 PRIMARY KEY  (`id`)
)

The User DAO

The DAO pattern provides a simple, consistent API for data access that does not require knowledge of an ORM interface. DAO does not just apply to simple mappings of one object to one relational table, but also allows complex queries to be performed and allows for stored procedures and database views to be mapped into data structures.

A typical DAO design pattern interface is shown below:

class Project_Dao_Db_User extends Zf_Db_Adapter
{
    public function fecthAll()
    {
        $db = $this->getConnection();
        $query = $db->select()->from('user');
        return $db->fetchAll($query);
    }

    public function fetchRowById($id)
    {
        $db = $this->getConnection();
        $query = $db->select()->from('user')->where('id = ?', $id);
        return $db->fetchRow($query);
    }

    public function insert($data)
    {
        $db = $this->getConnection();
        $db->insert('user', $data);
        return $db->lastInsertId();
    }

    public function update($id, $data)
    {
        $db = $this->getConnection();
        $where = $db->quoteInto('id = ?', $id);
        return $db->update('user', $data, $where);
    }

    public function delete($id)
    {
        $db = $this->getConnection();
        $where = $db->quoteInto('id = ?', $id);
        return $db->delete('user', $where);
    }
}

Source Code: Zf_Db_Adapter

The User Entity

An Entity is anything that has continuity through a life cycle and distinctions independent of attributes that are important to the application’s user.

class Project_Entity_User extends Zf_Domain_Entity
{
    public $id;
    public $firstName;
    public $lastName;
}

Source Code: Zf_Domain_Entity

The User DataMapper

class Project_DataMapper_User extends Zf_DataSource_Dao_Mapper
{
    protected $_map = array(
        'id'         => 'id',
        'first_name' => 'firstName',
        'last_name'  => 'lastName'
    );

    public function get($id)
    {
        $dao = new Project_Dao_Db_User();
        $row = $dao->fetchRowById($id);
        if (!$row) {
         return false;
        }
        return $this->map($row);
    }
}

Source Code: Zf_DataSource_Dao_Mapper

The User Model

The following class represents the User Relational Model:

class Project_Model_User
{
    public function getUser($id)
    {
        $mapper = new Project_DataMapper_User();
        $mapper->setEntity(new Project_Entity_User());
        $user = $mapper->get($id);

        return $user;
    }
}

The User Controller

class UserController extends Zend_Controller_Action
{
    public function viewAction()
    {
        $model = new Project_Model_User();
        $user = $model->getUser($this->_getParam('id'));
        if ($user) {
            $userId = $user->getId();
            $userFirstName = $user->getFirstName();
            $userLastName = $user->getLastName();

            // get an array of database fields and values
            $row = $user->getRow();
        }
    }
}

Keep in mind that ORM tools such as phpDataMapper and Doctrine offer an alternative way of modeling data. ORMs and ERMs are popular with Web frameworks, and the combination of an ORM and DDD makes DAOs redundant, however, it has not been proven to be better than a straightforward approach of implementing a collection of domain-specific data access functions.

That’s all, I hope you’ve found this post useful.

Written by Federico

September 19, 2009 at 12:23 pm

Increase speed and reduce bandwidth usage with ZF and Apache

with 18 comments

Apache’s mod_deflate module provides the DEFLATE output filter that allows output from your server to be compressed before being sent to the client over the network.

There are two ways of enabling gzip compression:

  1. Using Apache’s mod_deflate
  2. Using PHP’s built-in functions

Encoding the output and setting the appropriate headers manually makes the code more portable. Keep in mind that there are hundreds of Linux distributions, each slightly different to significantly different. To allow portability the application should not make assumptions about the OS or config involved.

Using Apache

1. Enable mod_deflate

Debian/Ubuntu:

$ a2enmod deflate
$ /etc/init.d/apache2 force-reload

2. Configure mode_deflate

$ nano /etc/apache2/mods-enabled/deflate.conf

#
# mod_deflate configuration
#
<IfModule mod_deflate.c>
 AddOutputFilterByType DEFLATE text/plain
 AddOutputFilterByType DEFLATE text/html
 AddOutputFilterByType DEFLATE text/xml
 AddOutputFilterByType DEFLATE text/css
 AddOutputFilterByType DEFLATE application/xml
 AddOutputFilterByType DEFLATE application/xhtml+xml
 AddOutputFilterByType DEFLATE application/rss+xml
 AddOutputFilterByType DEFLATE application/javascript
 AddOutputFilterByType DEFLATE application/x-javascript

 DeflateCompressionLevel 9

 BrowserMatch ^Mozilla/4 gzip-only-text/html
 BrowserMatch ^Mozilla/4\.0[678] no-gzip
 BrowserMatch \bMSIE !no-gzip !gzip-only-text/html

 DeflateFilterNote Input instream
 DeflateFilterNote Output outstream
 DeflateFilterNote Ratio ratio
</IfModule>

Using PHP

Create a gzip compressed string in your bootstrap file:

try {
    $frontController = Zend_Controller_Front::getInstance();
    if (@strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== false) {
        ob_start();
        $frontController->dispatch();
        $output = gzencode(ob_get_contents(), 9);
        ob_end_clean();
        header('Content-Encoding: gzip');
        echo $output;
    } else {
        $frontController->dispatch();
    }
} catch (Exeption $e) {
    if (Zend_Registry::isRegistered('Zend_Log')) {
        Zend_Registry::get('Zend_Log')->err($e->getMessage());
    }
    $message = $e->getMessage() . "\n\n" . $e->getTraceAsString();
    /* trigger event */
}

Reference

Use mod_deflate to compress Web content delivered by Apache

Written by Federico

July 6, 2009 at 11:09 am

Towards Community Cloud Computing

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Cloud Computing is rising fast, with its data centers growing at an unprecedented rate. However, this has come with concerns of privacy, efficiency at the expense of resilience, and environmental sustainability, because of the dependence on Cloud vendors such as Google, Amazon, and Microsoft. Community Cloud Computing makes use of the principles of Digital Ecosystems to provide a paradigm for Clouds in the community, offering an alternative architecture for the use cases of Cloud Computing. It is more technically challenging to deal with issues of distributed computing, such as latency, differential resource management, and additional security requirements. However, these are not insurmountable challenges, and with the need to retain control over our digital lives and the potential environmental consequences, it is a challenge we must pursue.

Towards Community Cloud Computing (Visit Site | Download PDF)

Written by Federico

July 4, 2009 at 7:43 pm

Format a time interval with the requested granularity

with 8 comments

This class, a refactored version of Drupal’s format_interval function, makes it relatively easy to format an interval value. The format will automatically format as compactly as possible. For example: if the difference between the two dates is only a few hours and both dates occur on the same day, the year, month, and day parts of the date will be omitted.

class DateIntervalFormat
{
    /**
     * Format an interval value with the requested granularity.
     *
     * @param integer $timestamp The length of the interval in seconds.
     * @param integer $granularity How many different units to display in the string.
     * @return string A string representation of the interval.
     */
    public function getInterval($timestamp, $granularity = 2)
    {
        $seconds = time() - $timestamp;
        $units = array(
            '1 year|:count years' => 31536000,
            '1 week|:count weeks' => 604800,
            '1 day|:count days' => 86400,
            '1 hour|:count hours' => 3600,
            '1 min|:count min' => 60,
            '1 sec|:count sec' => 1);
        $output = '';
        foreach ($units as $key => $value) {
            $key = explode('|', $key);
            if ($seconds >= $value) {
                $count = floor($seconds / $value);
                $output .= ($output ? ' ' : '');
                if ($count == 1) {
                    $output .= $key[0];
                } else {
                    $output .= str_replace(':count', $count, $key[1]);
                }
                $seconds %= $value;
                $granularity--;
            }
            if ($granularity == 0) {
                break;
            }
        }

        return $output ? $output : '0 sec';
    }
}

Usage:

$dateFormat = new DateIntervalFormat();
$timestamp = strtotime('2009-06-21 20:46:11');
print sprintf('Submitted %s ago',  $dateFormat->getInterval($timestamp));

Outputs:

Submitted 3 days 4 hours ago

Written by Federico

June 25, 2009 at 12:49 am

Face Detection Using PHP

leave a comment »

Maurice Svay explains how to detect faces in photos with PHP:

Nowadays, face detection is built in many consumer products (camera obviously, but also Google and iPhoto), and seems to be a pretty common job. So I expected to find many solutions for doing it with PHP. Surprisingly, the only one I could find is OpenCV, an opensource lib that was originally developed by Intel. OpenCV seems to perform well but you need to be able to install it on your server. In my case, I wanted to have a pure PHP solution, so it can work with most hosts.

Face detection in pure PHP (without OpenCV)

Written by Federico

June 24, 2009 at 4:09 pm

Posted in PHP

Apache HTTP DoS tool released

with 2 comments

Yesterday an interesting HTTP DoS tool has been released. The tool performs a Denial of Service attack on Apache (and some other, see below) servers by exhausting available connections. While there are a lot of DoS tools available today, this one is particularly interesting because it holds the connection open while sending incomplete HTTP requests to the server.

More info here

Written by Federico

June 22, 2009 at 8:29 pm

Posted in Linux, Security, Tools