symfony basics: form default values

This is some stuff for symfony beginners, who still want to learn symfony 1.4. You may set default form values for all kind of forms (including doctrine forms). Set one default value at a time:

class XxxForm extends BaseXxxForm
{
  public function configure()
  {
    $this->setDefault ('field', 'value');
  }
}

or set a whole array of them:

public function configure()
{
  $this->setDefaults(array(
    'field_1' => 'value_1',
    'field_2' => 'value_2',
    // ...
    'field_x' => 'value_x'
  ));
}

default values for new objects

Sometimes you want to set the default form values just before the object is created, because it'd be easier for the aplication user to fill in some data. For example, the owner/author of a blog post may be set default to the current logged in user - or the date of an event may be set to now - and so on. This can be achieved with the isNew method of the doctrine form class (lib/form/doctrine/XxxForm.class.php):

if ($this->isNew())
{
  $this->setDefault ('created_at'1, date('Y-m-d 00:00:00'));
  $this->setDefault ('created_by'2, sfContext::getInstance()->getUser()3->getId());
}

• note ¹: Timestampable Doctrine behavior used in this example,
• note ²: Signable Doctrine behavior used in this example,
• note ³: check this blog post to avoid using sfContext::getInstance().

moreover

You may implement whatever complex conditions you want your doctrine form to follow. Look at some of examples below:

• current time - php time function
• language/localization (default country when registering a new user) - use Accept-Language HTTP
• default settings set for a registered user - fetch individual user settings from database (doctrine query)
• last used item (category/product/etc.) - a user inserts or updates a large amount of data, when he choses a specific item (category/product) it can be saved in its session ($user->set/getAttribute()) - when another record is processed, last used item is used as default (which, again, lowers time needed for the user to work)

A well designed interface includes lots of form default values, so that users don't have to waste their time on picking up the same values over and over again.

symfony dynamic max_per_page

max_per_page

In this post I'll show a very easy and a really useful thing. It is dynamic max_per_page value of the list pager. Such feature gives you the possibility to change the number of elements displayed in a list just by one click. It can be used both in the frontend and backend (the pager is the same) - I'll use the doctrine generated admin module (and the interface will be placed inside the filters box):

templates

First, let's make it visible. Add the following entry to application config/app.yml file:

all:
  const:
    max_per_page: [ 10, 25, 50 ]

Now we may refer to app_const_max_per_page config value which holds few standard max_per_page values to be used (this can be used in many different admin modules). Let's say we've got an admin module for our custom MyModel model. Now, override the cached _filters.php template: fetch it from cache/admin/dev/modules/autoMyModel/templates and put it in apps/APP/modules/my_model/templates. Take a look at the following part of the code:

          </td>
        </tr>
      </tfoot>
      <tbody>
        <!-- insert here -->
        <tr>
          <td colspan="2">

and insert few lines of code (replace the comment) to get the following:

          </td>
        </tr>
      </tfoot>
      <tbody>
        <tr>
          <td colspan="2">
            set maximum elements per page:
            <?php foreach (sfConfig::get('app_const_max_per_page') as $value): ?>
              <span class="max_per_page_selector"><?php echo link_to($value, 'my_model/setMaxPerPage?max='.$value) ?></span>
            <?php endforeach; ?>
          </td>
        </tr>
        <tr>
          <td colspan="2">

controller/action

The interface to change max_per_page is ready, so we have to improve the controller now. Let's add an action which stores the number of elements to display per page in user session (symofny has nice set(get)Attributes methods). So here it comes:

  /**
   * Sets my_model list's max per page config value, using user session
   * attribute.
   *
   * @param sfWebRequest $request
   */
  public function executeSetMaxPerPage(sfWebRequest $request)
  {
    $this->getUser()->setAttribute('my_model.max_per_page', $max = $request->getParameter('max'));
    $this->getUser()->setFlash('notice', 'max_per_page has been set to: '.$max);
    $this->redirect('@my_model');
  }

configuration generator

And finally, tell the pager to look for the custom value each time the list is going to be rendered. We need to override the method in configuration generator of the admin module:

class my_modelGeneratorConfiguration extends BaseMy_modelGeneratorConfiguration
{
  /**
   * Returns max_per_page config value for my_model module. If it's not
   * defined manually by the user, default value is returned.
   *
   * @return Integer
   */
  public function getPagerMaxPerPage()
  {
    if ($max = sfContext::getInstance()->getUser()->getAttribute('my_model.max_per_page'))
      return $max;
    else
      return parent::getPagerMaxPerPage();
  }

It's all as easy as it could be. The controller searches the servers for the current user session data and returns either the custom data (if found) or the default value (which is taken from the generator.yml file).

Unfortunately, the sfContext::getInstance() is used here (this causes a lot of problems when the default context problem occurs). After a quick look I didn't find the better way to access the user from the configuration generator (but if you know how to - let me know ;).

(I'm wondering why it's not built in into symfony).

doctrine act as signable plugin - new releases

After few months, new versions 1.2.2 and 1.2.3 of sfDoctrineActAsSignablePlugin have been released. In short, the plugin provides a Signable behavior which automatically stores information on who has created or updated a given object.

what's new

A fellow symfony developer, Daniel Möllenbeck, suggested that there are some options missing in the behavior configuration. Until version 1.2.1, the onDelete option was hardcoded as CASCADE, which - as Daniel emphasised - may cause problems when a given user is supposed to be deleted (physically from the database, not softDeleted).

ALTER TABLE customer
ADD CONSTRAINT customer_created_by_sf_guard_user_id
FOREIGN KEY (created_by)
REFERENCES sf_guard_user(id)
ON DELETE CASCADE;

ALTER TABLE customer
ADD CONSTRAINT customer_updated_by_sf_guard_user_id
FOREIGN KEY (updated_by)
REFERENCES sf_guard_user(id)
ON DELETE CASCADE;

Let's imagine user enters customers over and over, then leaves the company. Now the admin deletes the user - probably the hard way (directly on the database, maybe the user is auto-created from somewhere...) --> The constraint will trigger the deletion of all customers created by that user. I have some doubt anybody would be happy about that.

Having the constraint like that does the trick:

a) allow NULL values in created_by/updated_by columns:

ALTER TABLE customer
ADD CONSTRAINT customer_created_by_sf_guard_user_id
FOREIGN KEY (created_by)
REFERENCES sf_guard_user(id)
ON DELETE SET NULL;

ALTER TABLE customer
ADD CONSTRAINT customer_updated_by_sf_guard_user_id
FOREIGN KEY (updated_by)
REFERENCES sf_guard_user(id)
ON DELETE SET NULL;

b) forbid the deletion of the user:

ALTER TABLE customer
ADD CONSTRAINT customer_created_by_sf_guard_user_id
FOREIGN KEY (created_by)
REFERENCES sf_guard_user(id)
ON DELETE RESTRICT;

ALTER TABLE customer
ADD CONSTRAINT customer_updated_by_sf_guard_user_id
FOREIGN KEY (updated_by)
REFERENCES sf_guard_user(id)
ON DELETE RESTRICT;

c) do nothing

moreover

Another fellow symfony developer, Christoph Berg, helped me to trace the bug with fixtures on created_by/updated_by values. Now, the bug is fixed and all fixture data works perfectly.

the community

Taking the opportunity, I'd like to thank Daniel, Christoph and all other symfony developers who share their opinions on my work - they help to find bugs and suggest some good ideas on how to improve the code. Thanks to you, the plugin gets better and better all the time. Thanks, guys!

Please, feel free to share your opinion and comment on the plugin!