Prendre un Café

Hey, it’s been a long time I didn’t blog something clever here on Symfony, let me try to remedy this.

I’ve just stumbled upon this blog post about the use of sfValidatorCallback, which is quite cool because by using this particular validator you can virtually employ any kind of php callable to validate something. But as the author warned, it can be problematic to tie the symfony form validation framework to your model classes.

Personnaly, I rather prefer to declare a method in the form class itself to validate some value without boring myself writing each time a new sfValidatorBase derived class^[1] :

<?php
class myForm extends sfForm
{
  public function configure()
  {
    $this->setWidgets(array(
      'name' => new sfWidgetFormInput(),
    ));
    
    $this->setValidators(array(
      'name' => new sfValidatorCallback(array('callback' => array($this, 'validateChuckNorris'))),
    ));
  }
  
  public function validateChuckNorris(sfValidatorBase $validator, $value)
  {
    // you can't validate chuck norris, but chuck norris can invalidate you
    if ('Chuck Norris' === $value)
    {
      throw new sfValidatorError($validator, 'invalid');
    }
  }
}

Of course, if you got the exact same need in another form, you should create a dedicated validator class. If you want custom error messages and options, you’ll have to create a dedicated class as well. But for simple and casual needs, this is just enough.

The neat thing with the sfValidatorCallback validator is you can even validate form schema values (say, an array containing all the values bound to the form) the same way, eg. using a post validator. Let’s see an example reusing the form shown previously:

<?php
class myForm extends sfForm
{
  static protected $choices = array(
    'none' => 'No emails', 
    'commercials' => 'Commercial emails', 
    'news' => 'Annoucement emails', 
    'alerts' => 'Alert emails',
  );
 
  public function configure()
  {
    $this->setWidgets(array(
      //...
      'email' => new sfWidgetFormInput(),
      'opt_in' => new sfWidgetFormSelectRadio(array('choices' => self::$choices)),
    ));
    
    $this->setValidators(array(
      //...
      'email' => new sfValidatorEmail(array('required' => false)),
      'opt_in' => new sfValidatorChoice(array('choices' => array_keys(self::$choices))),
    ));
    
    $this->validatorSchema->setPostValidator(new sfValidatorCallback(array(
      'callback' => array($this, 'validateSchema'),
    )));
  }
  
  // We want the user to provide his email if he choosed to receive stuff by email
  public function validateSchema(sfValidatorBase $validator, array $values)
  {
    if ($values['opt_in'] !== 'none' && !$values['email'])
    {
      throw new sfValidatorErrorSchema($validator, array(
        'email' => new sfValidatorError($validator, 'required'),
      ));
    }
  }
}

As a cool side effect, it will also make testing your form validation very easy, because you just have to test the callable method of your form.

Here’s another trick I stole to Kris on a project we worked together on lately, using a formatter callback to alter the presentation of a widget. Here’s an example showing how to get rid of the unordered list displaying a collection of checkboxes by default, by inlining them instead:

<?php
class myForm extends sfForm
{
  static protected $choices = array(
    'none' => 'No emails', 
    'commercials' => 'Commercial emails', 
    'news' => 'Annoucement emails', 
    'alerts' => 'Alert emails',
  );
 
  public function configure()
  {
    $this->setWidgets(array(
      //...
      'opt_in' => new sfWidgetFormSelectRadio(array(
        'choices' => self::$choices,
        'formatter' => array($this, 'formatInline'),
      )),
    ));
    
    $this->setValidators(array(
      //...
      'opt_in' => new sfValidatorChoice(array('choices' => array_keys(self::$choices))),
    ));
  }
  
  public function formatInline($widget, $inputs)
  {
    $formatted = array();
    
    foreach ($inputs as $input)
    {
      $formatted[] = $input['input'].' '.$input['label'];
    }
 
    return join(' ', $formatted);
  }
}

There are tons of little tricks like these which make the life of a developer using the forms framework easier, I’ll try to share them with you progressively.

It’s been quite a long time I didn’t give a go to Doctrine, so as it’s gonna be bundled by default in with the upcoming 1.2 release of symfony, I thought it was a good occasion to play with it.

So let’s checkout the 1.2 SVN branch of symfony and create a test project with a main application^[1]:

$ mkdir sf12test && cd sf12test
$ mkdir -p lib/vendor
$ svn co http://svn.symfony-project.com/branches/1.2 lib/vendor/symfony
$ php lib/vendor/symfony/data/bin/symfony generate:project sf12test
$ ln -s ../lib/vendor/symfony/data/web/sf web/sf
$ ./symfony generate:app main

Create a webserver vhost pointing to the web folder of the project directory. I’ve already explained plenty of times how to achieve this step.

Now, let’s enable the sfDoctrinePlugin and disable the Propel one by editing the setup() method of the config/ProjectConfiguration.class.php file:

public function setup()
  {
    $this->disablePlugins('sfPropelPlugin');
    $this->enablePlugins('sfDoctrinePlugin');
  }

You can list the available tasks running this simple command:

$ ./symfony list doctrine

Managing the Database Schema

First, configure your config/databases.yml file to set the database connection parameters. If you want to quick test Doctrine, use a local SQLite db, like this:

all:
  doctrine:
    class:    sfDoctrineDatabase
    param:
      dsn:    sqlite://<?php echo dirname(__FILE__).'/../data/data.db' ?>

We’re going to make a very simple weblog application, so let’s configure our database schema. We can do it in YAML^[2], so fire up your favorite editor/IDE and edit a brand new config/doctrine/schema.yml:

BlogPost:
  actAs:
    Sluggable:
      fields:       [title]
    Timestampable:
  columns:
    title:          string(255)
    body:           clob
    author:         string(255)
 
BlogComment:
  actAs:            [Timestampable]
  columns:
    blog_post_id:   integer
    author:         string(255)
    email:          string(255)
    content:        clob
  relations:
    BlogPost:
      class:        BlogPost
      local:        blog_post_id
      foreign:      id
      foreignType:  many
      type:         one

Note that Doctrine offers several pretty cool features including native behaviors (timestampable and slugable are used here).

Now, create a data/fixtures folder and put a data.yml file in, containing some test data in YAML format:

BlogPost:
  p1:
    title: My first post
    body: |
      This is cool.
    author: NiKo
    created_at: "<?php echo date('Y-m-d H:i:s', time() - 86400) ?>"
  p2:
    title: My second post
    body: |
      This is still cool.
    author: NiKo
    created_at: "<?php echo date('Y-m-d H:i:s', time() - 7200) ?>"
  p3:
    title: Third post
    body: |
      Is this one cool?
    author: Roger Hanin
    created_at: "<?php echo date('Y-m-d H:i:s') ?>"
 
BlogComment:
  c1:
    BlogPost: p3
    author: John
    email: john@doe.com
    content: Hey, you're right there.
    created_at: "<?php echo date('Y-m-d H:i:s', time() - 86400) ?>"
  c2:
    BlogPost: p3
    author: Paul
    email: paul@doe.com
    content: Nope, he's not.
    created_at: "<?php echo date('Y-m-d H:i:s') ?>"

Okay, now run the command below to generate the needed files, create the database and fill it with the data fixtures:

$ ./symfony doctrine:build-all-load

We can run several DQL queries in command line to check if everything is fine. DQL is very powerful, and compatible with a lot of RDBMS. You’ll find more information on DQL on the doctrine website.

For example, to find all blog posts:

$ ./symfony doctrine:dql "From BlogPost p"
found 3 results
-
  id: '21'
  title: 'My first post'
  body: "This is cool.\n"
  author: NiKo
  slug: my-first-post
  created_at: '2008-10-29 15:14:25'
  updated_at: '2008-10-30 15:14:25'
-
  id: '22'
  title: 'My second post'
  body: "This is still cool.\n"
  author: NiKo
  slug: my-second-post
  created_at: '2008-10-30 13:14:25'
  updated_at: '2008-10-30 15:14:25'
-
  id: '23'
  title: 'Third post'
  body: "Is this one cool?\n"
  author: 'Roger Hanin'
  slug: third-post
  created_at: '2008-10-30 15:14:25'
  updated_at: '2008-10-30 15:14:25'

Another example, to find informations about the blog post with slug third-post and its associated comments:

$ ./symfony doctrine:dql "Select p.title, p.author, c.author, c.content From BlogPost p, p.BlogComment c Where p.slug = 'third-post' Group by c.id"
found 3 results
-
  id: '23'
  title: 'Third post'
  author: 'Roger Hanin'
  BlogComment: [{ id: '15', author: John, content: 'Hey, you''re right there.' }, { id: '16', author: Paul, content: 'Nope, he''s not.' }]

Put the Query Logic in the Model

The Model part of any MVC architecture must contains the business data and associated logic. In other words, these data and logic should never be handled anywhere else, to decouple your components at max. So we’ll add some query methods in the lib/model/doctrine/BlogPostTable.class.php file, which represents our blog_post table and available operations on it:

<?php
class BlogPostTable extends Doctrine_Table
{
  public function getAll()
  {
    return Doctrine_Query::create()->
      select('p.title, p.slug, p.body, p.author, p.created_at, count(c.id) numcomments')->
      from('BlogPost p, p.BlogComment c')->
      orderBy('p.created_at DESC')->
      groupBy('p.id')->
      execute();
  }
 
  public function getOneBySlug($slug)
  {
    $posts = Doctrine_Query::create()->
      from('BlogPost p')->
      leftJoin('p.BlogComment c')->
      where('p.slug = ?')->
      orderBy('c.created_at ASC')->
      limit(1)->
      execute(array($slug));
 
    return isset($posts[0]) ? $posts[0] : null;
  }
}

A Weblog is About Web Interface, uh?

Okay, let’s add pretty controllers and templates to give some life to our blog. First, generate a post module in the main app:

$ ./symfony generate:module main post

Then, edit the apps/main/modules/post/actions/actions.class.php file:

<?php
class postActions extends sfActions
{
  public function executeIndex($request)
  {
    $this->posts = Doctrine::getTable('BlogPost')->getAll();
  }
  
  public function executeShow($request)
  {
    $this->post = Doctrine::getTable('BlogPost')->getOneBySlug($slug = $request->getParameter('slug'));
    $this->forward404Unless($this->post, 'No post with slug=' . $slug);
    $this->comments = $this->post->getBlogComment();
  }
}

We should have display templates too. The first one will show the posts list, in apps/main/modules/post/templates/indexSuccess.php:

<?php foreach ($posts as $post): ?>
  <?php include_partial('post/post', array('post' => $post, 'numComments' => $post->getNumcomments())) ?>
  <hr/>
<?php endforeach; ?>

Note that we must create the _post partial template, in apps/main/modules/post/templates/_post.php:

<h2><?php echo link_to($post->getTitle(), 'post/show?slug='.$post->getSlug()) ?></h2>
<p>
  <small>Posted by <?php echo $post->getAuthor() ?> on <?php echo $post->getCreatedAt() ?>
  <?php if (isset($numComments)): ?>
    - <?php echo $numComments ?> comments
  <?php endif; ?>
  </small>
</p>
<?php echo $post->getBody(ESC_RAW) ?>

The other main template will display one post and its comments, in apps/main/modules/post/templates/showSuccess.php:

<?php include_partial('post/post', array('post' => $post)) ?>
 
<h2>Comments</h2>
<?php if (!count($comments)): ?>
  <p>No comment yet.</p>
<?php else: ?>
<?php foreach ($comments as $comment): ?>
  <p><small>By <?php echo $comment->getAuthor() ?> on <?php echo $comment->getCreatedAt() ?></small></p>
  <blockquote><?php echo $comment->getContent() ?></blockquote>
<?php endforeach; ?>
<?php endif; ?>

That’s it. A rough but functional weblog if you lauch your browser to yourhost/main_dev.php/post/index:

And if you click a post title:

Good News, the Forms Framework Works with Doctrine Too

Symfony 1.1 introduced the new forms framework, and good news, Doctrine can take part of it. So maybe you’ve already noticed it, we have form classes generated already, in the lib/form/doctrine folder of the project.

So let’s add a neat commenting system to our blog, by first editing the lib/form/doctrine/BlogCommentForm.class.php file:

<?php
class BlogCommentForm extends BaseBlogCommentForm
{
  public function configure()
  {
    unset($this['id'], $this['created_at'], $this['updated_at']);
    
    $this->widgetSchema['blog_post_id'] = new sfWidgetFormInputHidden();
    
    $this->validatorSchema['author']  = new sfValidatorString(array('min_length' => 3));
    $this->validatorSchema['email']   = new sfValidatorEmail();
    $this->validatorSchema['content'] = new sfValidatorString(array('min_length' => 5));
  }
}

Now, use the form in the executeShow() method of our controller:

<?php
// ...
  public function executeShow($request)
  {
    $this->post = Doctrine::getTable('BlogPost')->getOneBySlug($slug = $request->getParameter('slug'));
    $this->forward404Unless($this->post, 'No post with slug=' . $slug);
    $this->comments = $this->post->getBlogComment();
    
    $comment = new BlogComment();
    $comment->setBlogPost($this->post);
    $this->form = new BlogCommentForm($comment);
    
    if ($request->isMethod('post') && $this->form->bindAndSave($request->getParameter('blog_comment')))
    {
      $this->redirect('post/show?slug='.$this->post->getSlug());
    }
  }

And in the showSuccess.php template, we’ll append the form display:

<h3>Add a comment</h3>
 
<?php echo $form->renderFormTag(url_for('post/show?slug='.$post->getSlug())) ?>
  <table>
    <?php echo $form ?>
    <tr>
      <td></td><td><input type="submit"/></td>
    </tr>
  </table>
</form>

We’ve now a pretty commeting system added to our blog, thanks to all the goodness provided by symfony and Doctrine:

Conclusion

The time when everyone choosed Propel because it was more stable than Doctrine seems to be over. Doctrine is robust, and performs quite well on my box. Furthermore, it handles complex relationships and dynamic object hydratation natively and better than Propel. Doctrine is also very well integrated into symfony, certainly because Jonathan Wage - the Doctrine lead developer - now works for Sensio, creator and main sponsor of symfony.

I’m back from the symfony camp 2008. It’s been a really great pleasure to meet the community^[1], there are so many smart people using symfony all around the world, it’s just amazing.

I gave a one day training session on symfony 1.1 to eleven attendees the day before, I think it was somewhat interesting even if it may have been too short to see every important aspects of the framework…

The conferences were also great, and some slides are already available:

• Edit: Opening Conference, by Lambert Beekhuis
• Be RESTful, by Fabien Potencier
• Beyond symfony 1.2, by Fabien
• Full Stack Web Application Performance Tuning, by Fabian Lange
• Debugging with symfony, by Stefan Koopmanschap
• The symfony Admin Generator, by Ian P. Christian
• Edit: Lessons Learned at Yahoo!, by Dustin Whittle
• Edit: Using YUI with symfony, by Dustin Whittle
• Edit: Developing for Developer, by François Zaninotto

Stefan has also taken some shots of the event.

Last and as a side note, as of now all my symfony related posts will be written in English, as it’s the main language used by the community.